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VAVACancer ColonColon Cancer Quality andand … · VAVACancer ColonColon Cancer Quality andand....
36
VA VA Colon Colon Cancer Cancer Quality Quality and and Cos Costs Study: Study: Es Estima timating ting Healthc Healthcar are Cos Costs fo for Colon Colon Cancer Cancer fo for Colon Colon Cancer Cancer Denise M. Hynes, RN, MPH, PhD Denise M. Hynes, RN, MPH, PhD Center for Management Center for Management of Complex of Complex Chronic Care & Chronic Care & VA Information Resource Information Resource Center Center, Edward Hines Jr , Edward Hines Jr. VA Hospital Hines, IL Hospital Hines, IL College of College of Medicine and Medicine and School of School of Public Health, Public Health, University University of of Illinois Illinois Chicago Chicago IL IL University University of of Illinois Illinois, Chicago Chicago, IL IL
Transcript of VAVACancer ColonColon Cancer Quality andand … · VAVACancer ColonColon Cancer Quality andand....
VAVA ColonColon CancerCancer QualityQuality andand CosCosttss StudyStudy EsEstimatimatingting HealthcHealthcararee CosCosttss
foforr ColonColon CancerCancerfoforr ColonColon CancerCancer Denise M Hynes RN MPH PhDDenise M Hynes RN MPH PhD
Center for ManagementCenter for Management of Complexof Complex Chronic Care ampChronic Care amp VVAA Information ResourceInformation Resource CenterCenter Edward Hines Jr Edward Hines Jr VVAA Hospital Hines ILHospital Hines IL
College ofCollege of Medicine andMedicine and School ofSchool of Public HealthPublic Health UniversityUniversity ofof IllinoisIllinois ChicagoChicago ILILUniversityUniversity ofof IllinoisIllinois ChicagoChicago ILIL
Focus for TodayFocus for Today
VA C l C Q lit f C d C t bull VA Colon Cancer Quality of Care and Cost Study
bull Approaches and Data Sources Used for Estimating CostsEstimating Costs
bull Alternative Methods for Dealing with Outliers and Impacts on Results
Overview
VA COLON CANCER QUALITY AND VA COLON CANCER QUALITY AND COSTS STUDY
ObjectiveObjective
bull Examine and compare healthcare use and costs for colon cancer ppatients treated in the Veterans Health Administration (VA) and MedicareMedicare
bull Completed study ffunded by VA HSRampD Service begun in 2004
4
ndashndash
AcknowledgementsAcknowledgements
bullbull AdvisorAdvisorssbullbull CCooaauutthhoorrssIInnveveststiiggatoatorrss ndashndash AlAl BensonBenson MDMD FAFACCPP
ElizElizabethabeth TaTarrlloovv PhDPhD RNRNElizElizabethabeth TaTarrlloovv PhDPhD RNRN ndashndash NirmalaNirmala BhoopalamBhoopalam MDMD ndashndash ToTodddd AA LeeLee PharmDPharmD PhDPhD ndashndash VivienVivien WW ChenChen PhDPhD
ndashndash MarMarcc TT GoodmanGoodman PhDPhDndashndash ThomasThomas WeWeiicchhllee MSMSThomasThomas WeWeiicchhllee MSMS ndashndash DaDawnwn PrProovvenzenzaalele MDMD ndashndash RamonRamon DurDuraazzoo‐‐ArArvizvizuu PhDPhD ndashndash BeBethth VirnigVirnig PhDPhD MPHMPH
ndashndash RuthRuth PPerrinerrin MAMA ndashndash MinMin WoWooonngg‐‐SohnSohn PhDPhDMinMin WoWooonngg SohnSohn PhDPhD
ndashndash QiuyingQiuying ZhangZhang MSMS ndashndash DaDavidvid BenBenttrreemm MDMD MSMS ndashndash CharlesCharles BennetBennettt MDMD PhDPhDndashndash RoRossaarriioo FFerrerreireiraa MDMD MAPPMAPP
Funding from the Department of Veterans Affairs (VA) Health Services Research and Development Service No IIR‐03‐196
5
~
How Much Does Colon Cancer Care Cost
bull Direct Medical CostDirect Medical Cost bull Est average cost of between $35000 and $80000 for each cancer
episode bull T tTotall cost f t for ttreattmentt off antiticiipattedd new cases ~ $8 3 billi $83 billion
bull Medicare Treatment Cost bull With first‐year Medicare treatment spending after detection
estimated at $35800 per case bull Medicare spending for new colorectal cancer cases ~ $2 4 billion $24 billionMedicare spending for new colorectal cancer cases
bull Treatment Cost Early Detection vs Late Stage bull Earlly ~ $$30000patient bull Late ~ $120000patient
20072007 estitimattes
6
Cost of Care Varies WidelyCost of Care Varies Widely
bull The total cost of chemotherapy to treat colorectal cancer mayy differ byy as much as $36999 per patient depending on the regimenregimen
ndash Lyman et al AmJ Managed Care 2008 (See Managed Care 2008 (See Variation in the cost of medications for the treatment of Variation in the cost of medications for the treatment ofLyman et al AmJ colorectal cancer Ferro SA Myer BS Wolff DA et al Am J Manag Care 2008 Nov14(11)717‐25)
7
VA and Cancer CareVA and Cancer Care
bull VA treats abbout 175000 cancer patients per year
bull VA cancer care is the focus of a conggressionallyy mandated Government Performance and Results Act study
bull Evaluation and measurement of cancer careEvaluation and measurement of cancer care and outcomes in the VA population is complicated by veteransrsquo use of both VA and complicated by veterans use of both VA and non‐VA
8
VA Cancer Care Facility CharacteristicsVA Cancer Care Facility Characteristics
Source Program Evaluation of Oncology Programs in the VHA ndash Survey of VA Facilities GPRA Evaluation 2006
What We Know About Dual VA and Medicare Users
bull Over 80 of elderly veterans eligible to use VA use Medicare alone or with VA services (Hynes et al 2007)
bull Empirical evidence of quality of care problems for general di l ill i l i l id i i (B kmedical illnesses in a multiple provider situation (Borowsky ampamp
Cowper 1999 and Petersen et al 2001)
bull Patients using more than one healthcare system may find coordination of care across systems to be lacking resulting in coordination of care across systems to be lacking resulting in delays in care and excessive healthcare use and costs
10
Colon Cancer Managgement Strateggies 1999‐2002
bull Stage 0 bull Stage IV Local excision or simple Surgical resection anastomosis or pp yp olypectomyy with clear marggins
b f l ibypass of priimary lesions
Radiation therapy to primary tumor bull Stage I amp II Wide surgical resection amp Surgical resection of isolated Surgical resection of isolated Wide surgical resection amp
anastomosis metastases (liver lung ovaries) Adjuvant chemotherapy in Adjuvant chemotherapy controlled clinical trials only
Clinical trials evaluating new drugs amp biologic therapy bull Stage III
Wide surgical resection amp Wide surgical resection amp anastomosis
Adjuvant chemotherapy
11
MethodsMethods
RRetrospectiive cohhort Dually eligible for VA and Medicare benefits At least 66 yrs old in 1999ndash2001
Matched amp linked to incident cancer record in VA Central Cancer Registry or one of 8 NCI SEER registriesregistries
ndash Participating SEER registries Atlanta California Detroit Hawaii Iowa Louisiana New Jersey ampDetroit Hawaii Iowa Louisiana New Jersey amp Western Washington
12
MethodsMethods
D l U Mbull Dual Use Measure ndash Specific to Colon Cancer Care
bull Collon cancer collectomy or chhemothherapy events indicated by diagnosis DRG procedure HCPCS BETOS revenue center clinic stop or pharmacy class codes
bull Calculated based on percentage of colon cancer specific inpatient and outpatient healthcare use in the VAinpatient and outpatient healthcare use in the VA
bull Three CC User Groups Dual Predominantly Medicare and P d i VAPredominantlly VA
13
e
Number of VA Colon Cancer
Related Inpatient Stays amp Outpatient
Events
Number of VA + Medicare Colon Cancer
Related Inpatient amp iStays amp Outpatient Events
0 140‐14 Predominantly Predominantly Medicare User
Percent of CarCare
Provided in VA
Dual CC User 15‐85
Predominantly VA User86ndash100
14
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Focus for TodayFocus for Today
VA C l C Q lit f C d C t bull VA Colon Cancer Quality of Care and Cost Study
bull Approaches and Data Sources Used for Estimating CostsEstimating Costs
bull Alternative Methods for Dealing with Outliers and Impacts on Results
Overview
VA COLON CANCER QUALITY AND VA COLON CANCER QUALITY AND COSTS STUDY
ObjectiveObjective
bull Examine and compare healthcare use and costs for colon cancer ppatients treated in the Veterans Health Administration (VA) and MedicareMedicare
bull Completed study ffunded by VA HSRampD Service begun in 2004
4
ndashndash
AcknowledgementsAcknowledgements
bullbull AdvisorAdvisorssbullbull CCooaauutthhoorrssIInnveveststiiggatoatorrss ndashndash AlAl BensonBenson MDMD FAFACCPP
ElizElizabethabeth TaTarrlloovv PhDPhD RNRNElizElizabethabeth TaTarrlloovv PhDPhD RNRN ndashndash NirmalaNirmala BhoopalamBhoopalam MDMD ndashndash ToTodddd AA LeeLee PharmDPharmD PhDPhD ndashndash VivienVivien WW ChenChen PhDPhD
ndashndash MarMarcc TT GoodmanGoodman PhDPhDndashndash ThomasThomas WeWeiicchhllee MSMSThomasThomas WeWeiicchhllee MSMS ndashndash DaDawnwn PrProovvenzenzaalele MDMD ndashndash RamonRamon DurDuraazzoo‐‐ArArvizvizuu PhDPhD ndashndash BeBethth VirnigVirnig PhDPhD MPHMPH
ndashndash RuthRuth PPerrinerrin MAMA ndashndash MinMin WoWooonngg‐‐SohnSohn PhDPhDMinMin WoWooonngg SohnSohn PhDPhD
ndashndash QiuyingQiuying ZhangZhang MSMS ndashndash DaDavidvid BenBenttrreemm MDMD MSMS ndashndash CharlesCharles BennetBennettt MDMD PhDPhDndashndash RoRossaarriioo FFerrerreireiraa MDMD MAPPMAPP
Funding from the Department of Veterans Affairs (VA) Health Services Research and Development Service No IIR‐03‐196
5
~
How Much Does Colon Cancer Care Cost
bull Direct Medical CostDirect Medical Cost bull Est average cost of between $35000 and $80000 for each cancer
episode bull T tTotall cost f t for ttreattmentt off antiticiipattedd new cases ~ $8 3 billi $83 billion
bull Medicare Treatment Cost bull With first‐year Medicare treatment spending after detection
estimated at $35800 per case bull Medicare spending for new colorectal cancer cases ~ $2 4 billion $24 billionMedicare spending for new colorectal cancer cases
bull Treatment Cost Early Detection vs Late Stage bull Earlly ~ $$30000patient bull Late ~ $120000patient
20072007 estitimattes
6
Cost of Care Varies WidelyCost of Care Varies Widely
bull The total cost of chemotherapy to treat colorectal cancer mayy differ byy as much as $36999 per patient depending on the regimenregimen
ndash Lyman et al AmJ Managed Care 2008 (See Managed Care 2008 (See Variation in the cost of medications for the treatment of Variation in the cost of medications for the treatment ofLyman et al AmJ colorectal cancer Ferro SA Myer BS Wolff DA et al Am J Manag Care 2008 Nov14(11)717‐25)
7
VA and Cancer CareVA and Cancer Care
bull VA treats abbout 175000 cancer patients per year
bull VA cancer care is the focus of a conggressionallyy mandated Government Performance and Results Act study
bull Evaluation and measurement of cancer careEvaluation and measurement of cancer care and outcomes in the VA population is complicated by veteransrsquo use of both VA and complicated by veterans use of both VA and non‐VA
8
VA Cancer Care Facility CharacteristicsVA Cancer Care Facility Characteristics
Source Program Evaluation of Oncology Programs in the VHA ndash Survey of VA Facilities GPRA Evaluation 2006
What We Know About Dual VA and Medicare Users
bull Over 80 of elderly veterans eligible to use VA use Medicare alone or with VA services (Hynes et al 2007)
bull Empirical evidence of quality of care problems for general di l ill i l i l id i i (B kmedical illnesses in a multiple provider situation (Borowsky ampamp
Cowper 1999 and Petersen et al 2001)
bull Patients using more than one healthcare system may find coordination of care across systems to be lacking resulting in coordination of care across systems to be lacking resulting in delays in care and excessive healthcare use and costs
10
Colon Cancer Managgement Strateggies 1999‐2002
bull Stage 0 bull Stage IV Local excision or simple Surgical resection anastomosis or pp yp olypectomyy with clear marggins
b f l ibypass of priimary lesions
Radiation therapy to primary tumor bull Stage I amp II Wide surgical resection amp Surgical resection of isolated Surgical resection of isolated Wide surgical resection amp
anastomosis metastases (liver lung ovaries) Adjuvant chemotherapy in Adjuvant chemotherapy controlled clinical trials only
Clinical trials evaluating new drugs amp biologic therapy bull Stage III
Wide surgical resection amp Wide surgical resection amp anastomosis
Adjuvant chemotherapy
11
MethodsMethods
RRetrospectiive cohhort Dually eligible for VA and Medicare benefits At least 66 yrs old in 1999ndash2001
Matched amp linked to incident cancer record in VA Central Cancer Registry or one of 8 NCI SEER registriesregistries
ndash Participating SEER registries Atlanta California Detroit Hawaii Iowa Louisiana New Jersey ampDetroit Hawaii Iowa Louisiana New Jersey amp Western Washington
12
MethodsMethods
D l U Mbull Dual Use Measure ndash Specific to Colon Cancer Care
bull Collon cancer collectomy or chhemothherapy events indicated by diagnosis DRG procedure HCPCS BETOS revenue center clinic stop or pharmacy class codes
bull Calculated based on percentage of colon cancer specific inpatient and outpatient healthcare use in the VAinpatient and outpatient healthcare use in the VA
bull Three CC User Groups Dual Predominantly Medicare and P d i VAPredominantlly VA
13
e
Number of VA Colon Cancer
Related Inpatient Stays amp Outpatient
Events
Number of VA + Medicare Colon Cancer
Related Inpatient amp iStays amp Outpatient Events
0 140‐14 Predominantly Predominantly Medicare User
Percent of CarCare
Provided in VA
Dual CC User 15‐85
Predominantly VA User86ndash100
14
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Overview
VA COLON CANCER QUALITY AND VA COLON CANCER QUALITY AND COSTS STUDY
ObjectiveObjective
bull Examine and compare healthcare use and costs for colon cancer ppatients treated in the Veterans Health Administration (VA) and MedicareMedicare
bull Completed study ffunded by VA HSRampD Service begun in 2004
4
ndashndash
AcknowledgementsAcknowledgements
bullbull AdvisorAdvisorssbullbull CCooaauutthhoorrssIInnveveststiiggatoatorrss ndashndash AlAl BensonBenson MDMD FAFACCPP
ElizElizabethabeth TaTarrlloovv PhDPhD RNRNElizElizabethabeth TaTarrlloovv PhDPhD RNRN ndashndash NirmalaNirmala BhoopalamBhoopalam MDMD ndashndash ToTodddd AA LeeLee PharmDPharmD PhDPhD ndashndash VivienVivien WW ChenChen PhDPhD
ndashndash MarMarcc TT GoodmanGoodman PhDPhDndashndash ThomasThomas WeWeiicchhllee MSMSThomasThomas WeWeiicchhllee MSMS ndashndash DaDawnwn PrProovvenzenzaalele MDMD ndashndash RamonRamon DurDuraazzoo‐‐ArArvizvizuu PhDPhD ndashndash BeBethth VirnigVirnig PhDPhD MPHMPH
ndashndash RuthRuth PPerrinerrin MAMA ndashndash MinMin WoWooonngg‐‐SohnSohn PhDPhDMinMin WoWooonngg SohnSohn PhDPhD
ndashndash QiuyingQiuying ZhangZhang MSMS ndashndash DaDavidvid BenBenttrreemm MDMD MSMS ndashndash CharlesCharles BennetBennettt MDMD PhDPhDndashndash RoRossaarriioo FFerrerreireiraa MDMD MAPPMAPP
Funding from the Department of Veterans Affairs (VA) Health Services Research and Development Service No IIR‐03‐196
5
~
How Much Does Colon Cancer Care Cost
bull Direct Medical CostDirect Medical Cost bull Est average cost of between $35000 and $80000 for each cancer
episode bull T tTotall cost f t for ttreattmentt off antiticiipattedd new cases ~ $8 3 billi $83 billion
bull Medicare Treatment Cost bull With first‐year Medicare treatment spending after detection
estimated at $35800 per case bull Medicare spending for new colorectal cancer cases ~ $2 4 billion $24 billionMedicare spending for new colorectal cancer cases
bull Treatment Cost Early Detection vs Late Stage bull Earlly ~ $$30000patient bull Late ~ $120000patient
20072007 estitimattes
6
Cost of Care Varies WidelyCost of Care Varies Widely
bull The total cost of chemotherapy to treat colorectal cancer mayy differ byy as much as $36999 per patient depending on the regimenregimen
ndash Lyman et al AmJ Managed Care 2008 (See Managed Care 2008 (See Variation in the cost of medications for the treatment of Variation in the cost of medications for the treatment ofLyman et al AmJ colorectal cancer Ferro SA Myer BS Wolff DA et al Am J Manag Care 2008 Nov14(11)717‐25)
7
VA and Cancer CareVA and Cancer Care
bull VA treats abbout 175000 cancer patients per year
bull VA cancer care is the focus of a conggressionallyy mandated Government Performance and Results Act study
bull Evaluation and measurement of cancer careEvaluation and measurement of cancer care and outcomes in the VA population is complicated by veteransrsquo use of both VA and complicated by veterans use of both VA and non‐VA
8
VA Cancer Care Facility CharacteristicsVA Cancer Care Facility Characteristics
Source Program Evaluation of Oncology Programs in the VHA ndash Survey of VA Facilities GPRA Evaluation 2006
What We Know About Dual VA and Medicare Users
bull Over 80 of elderly veterans eligible to use VA use Medicare alone or with VA services (Hynes et al 2007)
bull Empirical evidence of quality of care problems for general di l ill i l i l id i i (B kmedical illnesses in a multiple provider situation (Borowsky ampamp
Cowper 1999 and Petersen et al 2001)
bull Patients using more than one healthcare system may find coordination of care across systems to be lacking resulting in coordination of care across systems to be lacking resulting in delays in care and excessive healthcare use and costs
10
Colon Cancer Managgement Strateggies 1999‐2002
bull Stage 0 bull Stage IV Local excision or simple Surgical resection anastomosis or pp yp olypectomyy with clear marggins
b f l ibypass of priimary lesions
Radiation therapy to primary tumor bull Stage I amp II Wide surgical resection amp Surgical resection of isolated Surgical resection of isolated Wide surgical resection amp
anastomosis metastases (liver lung ovaries) Adjuvant chemotherapy in Adjuvant chemotherapy controlled clinical trials only
Clinical trials evaluating new drugs amp biologic therapy bull Stage III
Wide surgical resection amp Wide surgical resection amp anastomosis
Adjuvant chemotherapy
11
MethodsMethods
RRetrospectiive cohhort Dually eligible for VA and Medicare benefits At least 66 yrs old in 1999ndash2001
Matched amp linked to incident cancer record in VA Central Cancer Registry or one of 8 NCI SEER registriesregistries
ndash Participating SEER registries Atlanta California Detroit Hawaii Iowa Louisiana New Jersey ampDetroit Hawaii Iowa Louisiana New Jersey amp Western Washington
12
MethodsMethods
D l U Mbull Dual Use Measure ndash Specific to Colon Cancer Care
bull Collon cancer collectomy or chhemothherapy events indicated by diagnosis DRG procedure HCPCS BETOS revenue center clinic stop or pharmacy class codes
bull Calculated based on percentage of colon cancer specific inpatient and outpatient healthcare use in the VAinpatient and outpatient healthcare use in the VA
bull Three CC User Groups Dual Predominantly Medicare and P d i VAPredominantlly VA
13
e
Number of VA Colon Cancer
Related Inpatient Stays amp Outpatient
Events
Number of VA + Medicare Colon Cancer
Related Inpatient amp iStays amp Outpatient Events
0 140‐14 Predominantly Predominantly Medicare User
Percent of CarCare
Provided in VA
Dual CC User 15‐85
Predominantly VA User86ndash100
14
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
ObjectiveObjective
bull Examine and compare healthcare use and costs for colon cancer ppatients treated in the Veterans Health Administration (VA) and MedicareMedicare
bull Completed study ffunded by VA HSRampD Service begun in 2004
4
ndashndash
AcknowledgementsAcknowledgements
bullbull AdvisorAdvisorssbullbull CCooaauutthhoorrssIInnveveststiiggatoatorrss ndashndash AlAl BensonBenson MDMD FAFACCPP
ElizElizabethabeth TaTarrlloovv PhDPhD RNRNElizElizabethabeth TaTarrlloovv PhDPhD RNRN ndashndash NirmalaNirmala BhoopalamBhoopalam MDMD ndashndash ToTodddd AA LeeLee PharmDPharmD PhDPhD ndashndash VivienVivien WW ChenChen PhDPhD
ndashndash MarMarcc TT GoodmanGoodman PhDPhDndashndash ThomasThomas WeWeiicchhllee MSMSThomasThomas WeWeiicchhllee MSMS ndashndash DaDawnwn PrProovvenzenzaalele MDMD ndashndash RamonRamon DurDuraazzoo‐‐ArArvizvizuu PhDPhD ndashndash BeBethth VirnigVirnig PhDPhD MPHMPH
ndashndash RuthRuth PPerrinerrin MAMA ndashndash MinMin WoWooonngg‐‐SohnSohn PhDPhDMinMin WoWooonngg SohnSohn PhDPhD
ndashndash QiuyingQiuying ZhangZhang MSMS ndashndash DaDavidvid BenBenttrreemm MDMD MSMS ndashndash CharlesCharles BennetBennettt MDMD PhDPhDndashndash RoRossaarriioo FFerrerreireiraa MDMD MAPPMAPP
Funding from the Department of Veterans Affairs (VA) Health Services Research and Development Service No IIR‐03‐196
5
~
How Much Does Colon Cancer Care Cost
bull Direct Medical CostDirect Medical Cost bull Est average cost of between $35000 and $80000 for each cancer
episode bull T tTotall cost f t for ttreattmentt off antiticiipattedd new cases ~ $8 3 billi $83 billion
bull Medicare Treatment Cost bull With first‐year Medicare treatment spending after detection
estimated at $35800 per case bull Medicare spending for new colorectal cancer cases ~ $2 4 billion $24 billionMedicare spending for new colorectal cancer cases
bull Treatment Cost Early Detection vs Late Stage bull Earlly ~ $$30000patient bull Late ~ $120000patient
20072007 estitimattes
6
Cost of Care Varies WidelyCost of Care Varies Widely
bull The total cost of chemotherapy to treat colorectal cancer mayy differ byy as much as $36999 per patient depending on the regimenregimen
ndash Lyman et al AmJ Managed Care 2008 (See Managed Care 2008 (See Variation in the cost of medications for the treatment of Variation in the cost of medications for the treatment ofLyman et al AmJ colorectal cancer Ferro SA Myer BS Wolff DA et al Am J Manag Care 2008 Nov14(11)717‐25)
7
VA and Cancer CareVA and Cancer Care
bull VA treats abbout 175000 cancer patients per year
bull VA cancer care is the focus of a conggressionallyy mandated Government Performance and Results Act study
bull Evaluation and measurement of cancer careEvaluation and measurement of cancer care and outcomes in the VA population is complicated by veteransrsquo use of both VA and complicated by veterans use of both VA and non‐VA
8
VA Cancer Care Facility CharacteristicsVA Cancer Care Facility Characteristics
Source Program Evaluation of Oncology Programs in the VHA ndash Survey of VA Facilities GPRA Evaluation 2006
What We Know About Dual VA and Medicare Users
bull Over 80 of elderly veterans eligible to use VA use Medicare alone or with VA services (Hynes et al 2007)
bull Empirical evidence of quality of care problems for general di l ill i l i l id i i (B kmedical illnesses in a multiple provider situation (Borowsky ampamp
Cowper 1999 and Petersen et al 2001)
bull Patients using more than one healthcare system may find coordination of care across systems to be lacking resulting in coordination of care across systems to be lacking resulting in delays in care and excessive healthcare use and costs
10
Colon Cancer Managgement Strateggies 1999‐2002
bull Stage 0 bull Stage IV Local excision or simple Surgical resection anastomosis or pp yp olypectomyy with clear marggins
b f l ibypass of priimary lesions
Radiation therapy to primary tumor bull Stage I amp II Wide surgical resection amp Surgical resection of isolated Surgical resection of isolated Wide surgical resection amp
anastomosis metastases (liver lung ovaries) Adjuvant chemotherapy in Adjuvant chemotherapy controlled clinical trials only
Clinical trials evaluating new drugs amp biologic therapy bull Stage III
Wide surgical resection amp Wide surgical resection amp anastomosis
Adjuvant chemotherapy
11
MethodsMethods
RRetrospectiive cohhort Dually eligible for VA and Medicare benefits At least 66 yrs old in 1999ndash2001
Matched amp linked to incident cancer record in VA Central Cancer Registry or one of 8 NCI SEER registriesregistries
ndash Participating SEER registries Atlanta California Detroit Hawaii Iowa Louisiana New Jersey ampDetroit Hawaii Iowa Louisiana New Jersey amp Western Washington
12
MethodsMethods
D l U Mbull Dual Use Measure ndash Specific to Colon Cancer Care
bull Collon cancer collectomy or chhemothherapy events indicated by diagnosis DRG procedure HCPCS BETOS revenue center clinic stop or pharmacy class codes
bull Calculated based on percentage of colon cancer specific inpatient and outpatient healthcare use in the VAinpatient and outpatient healthcare use in the VA
bull Three CC User Groups Dual Predominantly Medicare and P d i VAPredominantlly VA
13
e
Number of VA Colon Cancer
Related Inpatient Stays amp Outpatient
Events
Number of VA + Medicare Colon Cancer
Related Inpatient amp iStays amp Outpatient Events
0 140‐14 Predominantly Predominantly Medicare User
Percent of CarCare
Provided in VA
Dual CC User 15‐85
Predominantly VA User86ndash100
14
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
ndashndash
AcknowledgementsAcknowledgements
bullbull AdvisorAdvisorssbullbull CCooaauutthhoorrssIInnveveststiiggatoatorrss ndashndash AlAl BensonBenson MDMD FAFACCPP
ElizElizabethabeth TaTarrlloovv PhDPhD RNRNElizElizabethabeth TaTarrlloovv PhDPhD RNRN ndashndash NirmalaNirmala BhoopalamBhoopalam MDMD ndashndash ToTodddd AA LeeLee PharmDPharmD PhDPhD ndashndash VivienVivien WW ChenChen PhDPhD
ndashndash MarMarcc TT GoodmanGoodman PhDPhDndashndash ThomasThomas WeWeiicchhllee MSMSThomasThomas WeWeiicchhllee MSMS ndashndash DaDawnwn PrProovvenzenzaalele MDMD ndashndash RamonRamon DurDuraazzoo‐‐ArArvizvizuu PhDPhD ndashndash BeBethth VirnigVirnig PhDPhD MPHMPH
ndashndash RuthRuth PPerrinerrin MAMA ndashndash MinMin WoWooonngg‐‐SohnSohn PhDPhDMinMin WoWooonngg SohnSohn PhDPhD
ndashndash QiuyingQiuying ZhangZhang MSMS ndashndash DaDavidvid BenBenttrreemm MDMD MSMS ndashndash CharlesCharles BennetBennettt MDMD PhDPhDndashndash RoRossaarriioo FFerrerreireiraa MDMD MAPPMAPP
Funding from the Department of Veterans Affairs (VA) Health Services Research and Development Service No IIR‐03‐196
5
~
How Much Does Colon Cancer Care Cost
bull Direct Medical CostDirect Medical Cost bull Est average cost of between $35000 and $80000 for each cancer
episode bull T tTotall cost f t for ttreattmentt off antiticiipattedd new cases ~ $8 3 billi $83 billion
bull Medicare Treatment Cost bull With first‐year Medicare treatment spending after detection
estimated at $35800 per case bull Medicare spending for new colorectal cancer cases ~ $2 4 billion $24 billionMedicare spending for new colorectal cancer cases
bull Treatment Cost Early Detection vs Late Stage bull Earlly ~ $$30000patient bull Late ~ $120000patient
20072007 estitimattes
6
Cost of Care Varies WidelyCost of Care Varies Widely
bull The total cost of chemotherapy to treat colorectal cancer mayy differ byy as much as $36999 per patient depending on the regimenregimen
ndash Lyman et al AmJ Managed Care 2008 (See Managed Care 2008 (See Variation in the cost of medications for the treatment of Variation in the cost of medications for the treatment ofLyman et al AmJ colorectal cancer Ferro SA Myer BS Wolff DA et al Am J Manag Care 2008 Nov14(11)717‐25)
7
VA and Cancer CareVA and Cancer Care
bull VA treats abbout 175000 cancer patients per year
bull VA cancer care is the focus of a conggressionallyy mandated Government Performance and Results Act study
bull Evaluation and measurement of cancer careEvaluation and measurement of cancer care and outcomes in the VA population is complicated by veteransrsquo use of both VA and complicated by veterans use of both VA and non‐VA
8
VA Cancer Care Facility CharacteristicsVA Cancer Care Facility Characteristics
Source Program Evaluation of Oncology Programs in the VHA ndash Survey of VA Facilities GPRA Evaluation 2006
What We Know About Dual VA and Medicare Users
bull Over 80 of elderly veterans eligible to use VA use Medicare alone or with VA services (Hynes et al 2007)
bull Empirical evidence of quality of care problems for general di l ill i l i l id i i (B kmedical illnesses in a multiple provider situation (Borowsky ampamp
Cowper 1999 and Petersen et al 2001)
bull Patients using more than one healthcare system may find coordination of care across systems to be lacking resulting in coordination of care across systems to be lacking resulting in delays in care and excessive healthcare use and costs
10
Colon Cancer Managgement Strateggies 1999‐2002
bull Stage 0 bull Stage IV Local excision or simple Surgical resection anastomosis or pp yp olypectomyy with clear marggins
b f l ibypass of priimary lesions
Radiation therapy to primary tumor bull Stage I amp II Wide surgical resection amp Surgical resection of isolated Surgical resection of isolated Wide surgical resection amp
anastomosis metastases (liver lung ovaries) Adjuvant chemotherapy in Adjuvant chemotherapy controlled clinical trials only
Clinical trials evaluating new drugs amp biologic therapy bull Stage III
Wide surgical resection amp Wide surgical resection amp anastomosis
Adjuvant chemotherapy
11
MethodsMethods
RRetrospectiive cohhort Dually eligible for VA and Medicare benefits At least 66 yrs old in 1999ndash2001
Matched amp linked to incident cancer record in VA Central Cancer Registry or one of 8 NCI SEER registriesregistries
ndash Participating SEER registries Atlanta California Detroit Hawaii Iowa Louisiana New Jersey ampDetroit Hawaii Iowa Louisiana New Jersey amp Western Washington
12
MethodsMethods
D l U Mbull Dual Use Measure ndash Specific to Colon Cancer Care
bull Collon cancer collectomy or chhemothherapy events indicated by diagnosis DRG procedure HCPCS BETOS revenue center clinic stop or pharmacy class codes
bull Calculated based on percentage of colon cancer specific inpatient and outpatient healthcare use in the VAinpatient and outpatient healthcare use in the VA
bull Three CC User Groups Dual Predominantly Medicare and P d i VAPredominantlly VA
13
e
Number of VA Colon Cancer
Related Inpatient Stays amp Outpatient
Events
Number of VA + Medicare Colon Cancer
Related Inpatient amp iStays amp Outpatient Events
0 140‐14 Predominantly Predominantly Medicare User
Percent of CarCare
Provided in VA
Dual CC User 15‐85
Predominantly VA User86ndash100
14
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
~
How Much Does Colon Cancer Care Cost
bull Direct Medical CostDirect Medical Cost bull Est average cost of between $35000 and $80000 for each cancer
episode bull T tTotall cost f t for ttreattmentt off antiticiipattedd new cases ~ $8 3 billi $83 billion
bull Medicare Treatment Cost bull With first‐year Medicare treatment spending after detection
estimated at $35800 per case bull Medicare spending for new colorectal cancer cases ~ $2 4 billion $24 billionMedicare spending for new colorectal cancer cases
bull Treatment Cost Early Detection vs Late Stage bull Earlly ~ $$30000patient bull Late ~ $120000patient
20072007 estitimattes
6
Cost of Care Varies WidelyCost of Care Varies Widely
bull The total cost of chemotherapy to treat colorectal cancer mayy differ byy as much as $36999 per patient depending on the regimenregimen
ndash Lyman et al AmJ Managed Care 2008 (See Managed Care 2008 (See Variation in the cost of medications for the treatment of Variation in the cost of medications for the treatment ofLyman et al AmJ colorectal cancer Ferro SA Myer BS Wolff DA et al Am J Manag Care 2008 Nov14(11)717‐25)
7
VA and Cancer CareVA and Cancer Care
bull VA treats abbout 175000 cancer patients per year
bull VA cancer care is the focus of a conggressionallyy mandated Government Performance and Results Act study
bull Evaluation and measurement of cancer careEvaluation and measurement of cancer care and outcomes in the VA population is complicated by veteransrsquo use of both VA and complicated by veterans use of both VA and non‐VA
8
VA Cancer Care Facility CharacteristicsVA Cancer Care Facility Characteristics
Source Program Evaluation of Oncology Programs in the VHA ndash Survey of VA Facilities GPRA Evaluation 2006
What We Know About Dual VA and Medicare Users
bull Over 80 of elderly veterans eligible to use VA use Medicare alone or with VA services (Hynes et al 2007)
bull Empirical evidence of quality of care problems for general di l ill i l i l id i i (B kmedical illnesses in a multiple provider situation (Borowsky ampamp
Cowper 1999 and Petersen et al 2001)
bull Patients using more than one healthcare system may find coordination of care across systems to be lacking resulting in coordination of care across systems to be lacking resulting in delays in care and excessive healthcare use and costs
10
Colon Cancer Managgement Strateggies 1999‐2002
bull Stage 0 bull Stage IV Local excision or simple Surgical resection anastomosis or pp yp olypectomyy with clear marggins
b f l ibypass of priimary lesions
Radiation therapy to primary tumor bull Stage I amp II Wide surgical resection amp Surgical resection of isolated Surgical resection of isolated Wide surgical resection amp
anastomosis metastases (liver lung ovaries) Adjuvant chemotherapy in Adjuvant chemotherapy controlled clinical trials only
Clinical trials evaluating new drugs amp biologic therapy bull Stage III
Wide surgical resection amp Wide surgical resection amp anastomosis
Adjuvant chemotherapy
11
MethodsMethods
RRetrospectiive cohhort Dually eligible for VA and Medicare benefits At least 66 yrs old in 1999ndash2001
Matched amp linked to incident cancer record in VA Central Cancer Registry or one of 8 NCI SEER registriesregistries
ndash Participating SEER registries Atlanta California Detroit Hawaii Iowa Louisiana New Jersey ampDetroit Hawaii Iowa Louisiana New Jersey amp Western Washington
12
MethodsMethods
D l U Mbull Dual Use Measure ndash Specific to Colon Cancer Care
bull Collon cancer collectomy or chhemothherapy events indicated by diagnosis DRG procedure HCPCS BETOS revenue center clinic stop or pharmacy class codes
bull Calculated based on percentage of colon cancer specific inpatient and outpatient healthcare use in the VAinpatient and outpatient healthcare use in the VA
bull Three CC User Groups Dual Predominantly Medicare and P d i VAPredominantlly VA
13
e
Number of VA Colon Cancer
Related Inpatient Stays amp Outpatient
Events
Number of VA + Medicare Colon Cancer
Related Inpatient amp iStays amp Outpatient Events
0 140‐14 Predominantly Predominantly Medicare User
Percent of CarCare
Provided in VA
Dual CC User 15‐85
Predominantly VA User86ndash100
14
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Cost of Care Varies WidelyCost of Care Varies Widely
bull The total cost of chemotherapy to treat colorectal cancer mayy differ byy as much as $36999 per patient depending on the regimenregimen
ndash Lyman et al AmJ Managed Care 2008 (See Managed Care 2008 (See Variation in the cost of medications for the treatment of Variation in the cost of medications for the treatment ofLyman et al AmJ colorectal cancer Ferro SA Myer BS Wolff DA et al Am J Manag Care 2008 Nov14(11)717‐25)
7
VA and Cancer CareVA and Cancer Care
bull VA treats abbout 175000 cancer patients per year
bull VA cancer care is the focus of a conggressionallyy mandated Government Performance and Results Act study
bull Evaluation and measurement of cancer careEvaluation and measurement of cancer care and outcomes in the VA population is complicated by veteransrsquo use of both VA and complicated by veterans use of both VA and non‐VA
8
VA Cancer Care Facility CharacteristicsVA Cancer Care Facility Characteristics
Source Program Evaluation of Oncology Programs in the VHA ndash Survey of VA Facilities GPRA Evaluation 2006
What We Know About Dual VA and Medicare Users
bull Over 80 of elderly veterans eligible to use VA use Medicare alone or with VA services (Hynes et al 2007)
bull Empirical evidence of quality of care problems for general di l ill i l i l id i i (B kmedical illnesses in a multiple provider situation (Borowsky ampamp
Cowper 1999 and Petersen et al 2001)
bull Patients using more than one healthcare system may find coordination of care across systems to be lacking resulting in coordination of care across systems to be lacking resulting in delays in care and excessive healthcare use and costs
10
Colon Cancer Managgement Strateggies 1999‐2002
bull Stage 0 bull Stage IV Local excision or simple Surgical resection anastomosis or pp yp olypectomyy with clear marggins
b f l ibypass of priimary lesions
Radiation therapy to primary tumor bull Stage I amp II Wide surgical resection amp Surgical resection of isolated Surgical resection of isolated Wide surgical resection amp
anastomosis metastases (liver lung ovaries) Adjuvant chemotherapy in Adjuvant chemotherapy controlled clinical trials only
Clinical trials evaluating new drugs amp biologic therapy bull Stage III
Wide surgical resection amp Wide surgical resection amp anastomosis
Adjuvant chemotherapy
11
MethodsMethods
RRetrospectiive cohhort Dually eligible for VA and Medicare benefits At least 66 yrs old in 1999ndash2001
Matched amp linked to incident cancer record in VA Central Cancer Registry or one of 8 NCI SEER registriesregistries
ndash Participating SEER registries Atlanta California Detroit Hawaii Iowa Louisiana New Jersey ampDetroit Hawaii Iowa Louisiana New Jersey amp Western Washington
12
MethodsMethods
D l U Mbull Dual Use Measure ndash Specific to Colon Cancer Care
bull Collon cancer collectomy or chhemothherapy events indicated by diagnosis DRG procedure HCPCS BETOS revenue center clinic stop or pharmacy class codes
bull Calculated based on percentage of colon cancer specific inpatient and outpatient healthcare use in the VAinpatient and outpatient healthcare use in the VA
bull Three CC User Groups Dual Predominantly Medicare and P d i VAPredominantlly VA
13
e
Number of VA Colon Cancer
Related Inpatient Stays amp Outpatient
Events
Number of VA + Medicare Colon Cancer
Related Inpatient amp iStays amp Outpatient Events
0 140‐14 Predominantly Predominantly Medicare User
Percent of CarCare
Provided in VA
Dual CC User 15‐85
Predominantly VA User86ndash100
14
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
VA and Cancer CareVA and Cancer Care
bull VA treats abbout 175000 cancer patients per year
bull VA cancer care is the focus of a conggressionallyy mandated Government Performance and Results Act study
bull Evaluation and measurement of cancer careEvaluation and measurement of cancer care and outcomes in the VA population is complicated by veteransrsquo use of both VA and complicated by veterans use of both VA and non‐VA
8
VA Cancer Care Facility CharacteristicsVA Cancer Care Facility Characteristics
Source Program Evaluation of Oncology Programs in the VHA ndash Survey of VA Facilities GPRA Evaluation 2006
What We Know About Dual VA and Medicare Users
bull Over 80 of elderly veterans eligible to use VA use Medicare alone or with VA services (Hynes et al 2007)
bull Empirical evidence of quality of care problems for general di l ill i l i l id i i (B kmedical illnesses in a multiple provider situation (Borowsky ampamp
Cowper 1999 and Petersen et al 2001)
bull Patients using more than one healthcare system may find coordination of care across systems to be lacking resulting in coordination of care across systems to be lacking resulting in delays in care and excessive healthcare use and costs
10
Colon Cancer Managgement Strateggies 1999‐2002
bull Stage 0 bull Stage IV Local excision or simple Surgical resection anastomosis or pp yp olypectomyy with clear marggins
b f l ibypass of priimary lesions
Radiation therapy to primary tumor bull Stage I amp II Wide surgical resection amp Surgical resection of isolated Surgical resection of isolated Wide surgical resection amp
anastomosis metastases (liver lung ovaries) Adjuvant chemotherapy in Adjuvant chemotherapy controlled clinical trials only
Clinical trials evaluating new drugs amp biologic therapy bull Stage III
Wide surgical resection amp Wide surgical resection amp anastomosis
Adjuvant chemotherapy
11
MethodsMethods
RRetrospectiive cohhort Dually eligible for VA and Medicare benefits At least 66 yrs old in 1999ndash2001
Matched amp linked to incident cancer record in VA Central Cancer Registry or one of 8 NCI SEER registriesregistries
ndash Participating SEER registries Atlanta California Detroit Hawaii Iowa Louisiana New Jersey ampDetroit Hawaii Iowa Louisiana New Jersey amp Western Washington
12
MethodsMethods
D l U Mbull Dual Use Measure ndash Specific to Colon Cancer Care
bull Collon cancer collectomy or chhemothherapy events indicated by diagnosis DRG procedure HCPCS BETOS revenue center clinic stop or pharmacy class codes
bull Calculated based on percentage of colon cancer specific inpatient and outpatient healthcare use in the VAinpatient and outpatient healthcare use in the VA
bull Three CC User Groups Dual Predominantly Medicare and P d i VAPredominantlly VA
13
e
Number of VA Colon Cancer
Related Inpatient Stays amp Outpatient
Events
Number of VA + Medicare Colon Cancer
Related Inpatient amp iStays amp Outpatient Events
0 140‐14 Predominantly Predominantly Medicare User
Percent of CarCare
Provided in VA
Dual CC User 15‐85
Predominantly VA User86ndash100
14
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
VA Cancer Care Facility CharacteristicsVA Cancer Care Facility Characteristics
Source Program Evaluation of Oncology Programs in the VHA ndash Survey of VA Facilities GPRA Evaluation 2006
What We Know About Dual VA and Medicare Users
bull Over 80 of elderly veterans eligible to use VA use Medicare alone or with VA services (Hynes et al 2007)
bull Empirical evidence of quality of care problems for general di l ill i l i l id i i (B kmedical illnesses in a multiple provider situation (Borowsky ampamp
Cowper 1999 and Petersen et al 2001)
bull Patients using more than one healthcare system may find coordination of care across systems to be lacking resulting in coordination of care across systems to be lacking resulting in delays in care and excessive healthcare use and costs
10
Colon Cancer Managgement Strateggies 1999‐2002
bull Stage 0 bull Stage IV Local excision or simple Surgical resection anastomosis or pp yp olypectomyy with clear marggins
b f l ibypass of priimary lesions
Radiation therapy to primary tumor bull Stage I amp II Wide surgical resection amp Surgical resection of isolated Surgical resection of isolated Wide surgical resection amp
anastomosis metastases (liver lung ovaries) Adjuvant chemotherapy in Adjuvant chemotherapy controlled clinical trials only
Clinical trials evaluating new drugs amp biologic therapy bull Stage III
Wide surgical resection amp Wide surgical resection amp anastomosis
Adjuvant chemotherapy
11
MethodsMethods
RRetrospectiive cohhort Dually eligible for VA and Medicare benefits At least 66 yrs old in 1999ndash2001
Matched amp linked to incident cancer record in VA Central Cancer Registry or one of 8 NCI SEER registriesregistries
ndash Participating SEER registries Atlanta California Detroit Hawaii Iowa Louisiana New Jersey ampDetroit Hawaii Iowa Louisiana New Jersey amp Western Washington
12
MethodsMethods
D l U Mbull Dual Use Measure ndash Specific to Colon Cancer Care
bull Collon cancer collectomy or chhemothherapy events indicated by diagnosis DRG procedure HCPCS BETOS revenue center clinic stop or pharmacy class codes
bull Calculated based on percentage of colon cancer specific inpatient and outpatient healthcare use in the VAinpatient and outpatient healthcare use in the VA
bull Three CC User Groups Dual Predominantly Medicare and P d i VAPredominantlly VA
13
e
Number of VA Colon Cancer
Related Inpatient Stays amp Outpatient
Events
Number of VA + Medicare Colon Cancer
Related Inpatient amp iStays amp Outpatient Events
0 140‐14 Predominantly Predominantly Medicare User
Percent of CarCare
Provided in VA
Dual CC User 15‐85
Predominantly VA User86ndash100
14
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
What We Know About Dual VA and Medicare Users
bull Over 80 of elderly veterans eligible to use VA use Medicare alone or with VA services (Hynes et al 2007)
bull Empirical evidence of quality of care problems for general di l ill i l i l id i i (B kmedical illnesses in a multiple provider situation (Borowsky ampamp
Cowper 1999 and Petersen et al 2001)
bull Patients using more than one healthcare system may find coordination of care across systems to be lacking resulting in coordination of care across systems to be lacking resulting in delays in care and excessive healthcare use and costs
10
Colon Cancer Managgement Strateggies 1999‐2002
bull Stage 0 bull Stage IV Local excision or simple Surgical resection anastomosis or pp yp olypectomyy with clear marggins
b f l ibypass of priimary lesions
Radiation therapy to primary tumor bull Stage I amp II Wide surgical resection amp Surgical resection of isolated Surgical resection of isolated Wide surgical resection amp
anastomosis metastases (liver lung ovaries) Adjuvant chemotherapy in Adjuvant chemotherapy controlled clinical trials only
Clinical trials evaluating new drugs amp biologic therapy bull Stage III
Wide surgical resection amp Wide surgical resection amp anastomosis
Adjuvant chemotherapy
11
MethodsMethods
RRetrospectiive cohhort Dually eligible for VA and Medicare benefits At least 66 yrs old in 1999ndash2001
Matched amp linked to incident cancer record in VA Central Cancer Registry or one of 8 NCI SEER registriesregistries
ndash Participating SEER registries Atlanta California Detroit Hawaii Iowa Louisiana New Jersey ampDetroit Hawaii Iowa Louisiana New Jersey amp Western Washington
12
MethodsMethods
D l U Mbull Dual Use Measure ndash Specific to Colon Cancer Care
bull Collon cancer collectomy or chhemothherapy events indicated by diagnosis DRG procedure HCPCS BETOS revenue center clinic stop or pharmacy class codes
bull Calculated based on percentage of colon cancer specific inpatient and outpatient healthcare use in the VAinpatient and outpatient healthcare use in the VA
bull Three CC User Groups Dual Predominantly Medicare and P d i VAPredominantlly VA
13
e
Number of VA Colon Cancer
Related Inpatient Stays amp Outpatient
Events
Number of VA + Medicare Colon Cancer
Related Inpatient amp iStays amp Outpatient Events
0 140‐14 Predominantly Predominantly Medicare User
Percent of CarCare
Provided in VA
Dual CC User 15‐85
Predominantly VA User86ndash100
14
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Colon Cancer Managgement Strateggies 1999‐2002
bull Stage 0 bull Stage IV Local excision or simple Surgical resection anastomosis or pp yp olypectomyy with clear marggins
b f l ibypass of priimary lesions
Radiation therapy to primary tumor bull Stage I amp II Wide surgical resection amp Surgical resection of isolated Surgical resection of isolated Wide surgical resection amp
anastomosis metastases (liver lung ovaries) Adjuvant chemotherapy in Adjuvant chemotherapy controlled clinical trials only
Clinical trials evaluating new drugs amp biologic therapy bull Stage III
Wide surgical resection amp Wide surgical resection amp anastomosis
Adjuvant chemotherapy
11
MethodsMethods
RRetrospectiive cohhort Dually eligible for VA and Medicare benefits At least 66 yrs old in 1999ndash2001
Matched amp linked to incident cancer record in VA Central Cancer Registry or one of 8 NCI SEER registriesregistries
ndash Participating SEER registries Atlanta California Detroit Hawaii Iowa Louisiana New Jersey ampDetroit Hawaii Iowa Louisiana New Jersey amp Western Washington
12
MethodsMethods
D l U Mbull Dual Use Measure ndash Specific to Colon Cancer Care
bull Collon cancer collectomy or chhemothherapy events indicated by diagnosis DRG procedure HCPCS BETOS revenue center clinic stop or pharmacy class codes
bull Calculated based on percentage of colon cancer specific inpatient and outpatient healthcare use in the VAinpatient and outpatient healthcare use in the VA
bull Three CC User Groups Dual Predominantly Medicare and P d i VAPredominantlly VA
13
e
Number of VA Colon Cancer
Related Inpatient Stays amp Outpatient
Events
Number of VA + Medicare Colon Cancer
Related Inpatient amp iStays amp Outpatient Events
0 140‐14 Predominantly Predominantly Medicare User
Percent of CarCare
Provided in VA
Dual CC User 15‐85
Predominantly VA User86ndash100
14
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
MethodsMethods
RRetrospectiive cohhort Dually eligible for VA and Medicare benefits At least 66 yrs old in 1999ndash2001
Matched amp linked to incident cancer record in VA Central Cancer Registry or one of 8 NCI SEER registriesregistries
ndash Participating SEER registries Atlanta California Detroit Hawaii Iowa Louisiana New Jersey ampDetroit Hawaii Iowa Louisiana New Jersey amp Western Washington
12
MethodsMethods
D l U Mbull Dual Use Measure ndash Specific to Colon Cancer Care
bull Collon cancer collectomy or chhemothherapy events indicated by diagnosis DRG procedure HCPCS BETOS revenue center clinic stop or pharmacy class codes
bull Calculated based on percentage of colon cancer specific inpatient and outpatient healthcare use in the VAinpatient and outpatient healthcare use in the VA
bull Three CC User Groups Dual Predominantly Medicare and P d i VAPredominantlly VA
13
e
Number of VA Colon Cancer
Related Inpatient Stays amp Outpatient
Events
Number of VA + Medicare Colon Cancer
Related Inpatient amp iStays amp Outpatient Events
0 140‐14 Predominantly Predominantly Medicare User
Percent of CarCare
Provided in VA
Dual CC User 15‐85
Predominantly VA User86ndash100
14
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
MethodsMethods
D l U Mbull Dual Use Measure ndash Specific to Colon Cancer Care
bull Collon cancer collectomy or chhemothherapy events indicated by diagnosis DRG procedure HCPCS BETOS revenue center clinic stop or pharmacy class codes
bull Calculated based on percentage of colon cancer specific inpatient and outpatient healthcare use in the VAinpatient and outpatient healthcare use in the VA
bull Three CC User Groups Dual Predominantly Medicare and P d i VAPredominantlly VA
13
e
Number of VA Colon Cancer
Related Inpatient Stays amp Outpatient
Events
Number of VA + Medicare Colon Cancer
Related Inpatient amp iStays amp Outpatient Events
0 140‐14 Predominantly Predominantly Medicare User
Percent of CarCare
Provided in VA
Dual CC User 15‐85
Predominantly VA User86ndash100
14
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
e
Number of VA Colon Cancer
Related Inpatient Stays amp Outpatient
Events
Number of VA + Medicare Colon Cancer
Related Inpatient amp iStays amp Outpatient Events
0 140‐14 Predominantly Predominantly Medicare User
Percent of CarCare
Provided in VA
Dual CC User 15‐85
Predominantly VA User86ndash100
14
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Methods
APPROACHES AND DATA SOURCES USED FOR ESTIMATING COSTSUSED FOR ESTIMATING COSTS
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
-
VIReC Finder file VIReC Finder file Veterans known to VA at least 66 years old
dually eligible to use VHA and Medicare between 1999-2001between 1999 2001
3482654
Exclusions 1 485 Exclusions 1485 Incomplete or absent utilization information
At some point during the study period Not enrolled or not eligible for VA care (259)g ( ) Medicare HMO enrollment (1056) Non-Medicare primary payer (private insurance) (86) Medicare Part B coverage only (19)
No healthcare utilization records during study period No healthcare utilization records during study period reason unknown (60) No utilization records during 6-month period surrounding diagnosis date reason unknown (438)
(1 )Autopsy-only diagnosis (15)
No colon cancer-related health care within 12 month after diagnosis (101)
Zero colon cancer related costs (92)Zero colon cancer-related costs (92)
8 SEER program registries 8 SEER program registries California Iowa Georgia Louisiana New Jersey Hawaii
Western Washington Metro Detroit Metro Detroit
and VA Central Cancer Registry
Match yield Veterans with
stage IndashIV colon cancer stage I IV colon cancer diagnosed between
7199-123101 who were 66 years or older
at the time of diagnosis at the time of diagnosis 5327
Analytical cohort 3842
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
ndash
Summary of Data Sources UsedSummary of Data Sources Used
bull Define Cohort
ndash VIReC Finder File
ndash NCI SEER (8)
ndash VA Central Cancer Registry (VA CCR)VA Central Cancer Registry (VA CCR)
bull Determine Exclusions based on Healthcare Use
ndash VA Workload data‐‐MEDSAS
ndash Medicare Claims
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Methods Measuring CostsMethods Measuring Costs
12 M th 12 Months ffrom diagnosiisbull di bull Valuation
ndash VAVA costt valued usiing H lth E Health Economiic Resource l d R Center (HERC) average cost approach
ndash Medicare valued using Medicare paymentsMedicare valued using Medicare payments bull Includes
ndash VA and Medicare acute and intermediate inpatientVA and Medicare acute and intermediate inpatient and outpatient utilization including pharmacy
bull Excludes ndash VA long term care ndash Medicare home health care hospice amp DME
18
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
A l iAnalysis
bull Healthcare use amp costs within 12 months after diagnosis
Descriptive analyses (Statatrade) Comppared overall (inpatient and outpatient)) costs ( p p Examined association of user group (Dual Predominantly Medicare
Predominantly VA) with costs Adjjusted for ppredispposingg enablingg and contextual factors
Multivariable regression analysis (GLM) (StataMultiv regression analysis (GLM) (Stata trade)) ariable
All costs adjusted to 2004 dollars
19
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Age at diagnosis (yrs) 66ndash75 492
76 85 45 8 76ndash85 458 86 and older 50
Gender Male 96 5 Gender Male 965 Race African American 155 Marital status Not married 37 7 Marital status Not married 377
Married 596 Unknown 28
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Cohort Characteristics (N=3 842)Cohort Characteristics (N=3842)
Stage at diagnosis I 268Stage at diagnosis I 268
II 307 III 232 IV 193
Comorbidity scoreb 0 514 1 25 6 1 256 2ndash3 185 4 or higher 4 54 or higher 45
Chemotherapyc Yes 336 Colectomyd Yes 894y b Measured from months ‐6 to 0 in study period c Measured from months 0 to 12 in study period d Measured from months ‐1 to 6 in study period
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
( )
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
N Mean (SD) N Mean (SD) N Mean (SD) Total CC Costs 1417 39136 (31567) 510 44264 (50567) 1915 36146 (37060)
Inpatient 1370 32907 (29836) 492 42174 (50866) 1808 34587 (37217)
VA 35 37166 (42554) 340 41785 (51806) 1797 34163 (37132)
Medicare 1357 32264 (29159) 337 19181 (18622) 83 11199 (13129)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
VA 166 357 (462) 460 1213 (1976) 1697 3800 (5633)
Medicare 1306 7897 (10557) 453 2750 (5967) 186 429 (903)
All significant at Plt001 22
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Colon Cancer Care 12 Month Use By User Group (N=3842)
Predominantly Predominantly Medicare Dual use VA (N 1 417) (N = 1417) (N 510)(N = 510) (N 1 915) (N = 1915)
Mean (SD) Inpatient admissions per
( ) ( ) ( )patient 15 (10) 19 (12) 15 (13) Days per inpatient admission 137 (158) 155 (190) 132 (247) T t l i ti t d Total inpatient days per patient 213 (234) 294 (337) 208 (324)
Outpatient visits per patient Outpatient visits per patient 35 7 (29 9) 357 (299) 19 2 (22 0) 192 (220) 13 5 (16 6) 135 (166)
Total outpatient visit days 248 (201) 144 (144) 121 (144)
All significant at Plt00001
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
ndash
a ed
Estimated Expense Rate Ratios (N=3842)
AdjustedAdjusted ERRERR (95 Confidence Intervals)
Age at Diagnosis 66ndash7566 75 76ndash85 86 and older
RaceRace Non‐African American African American
Married No Yes Unknown
Stage at diagnosis I II III IV
Ref Ref 117 (108ndash127) 124 (104ndash147)
Ref 114 (103ndash128)
Ref 088 (081ndash095) 058 (040‐086)( )
Ref 137 (123ndash153) 184 (163ndash207) 227 (201ndash256)
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Estimated Expense Rate Ratios (N 3 842) (N=3842)
Adjusted ERR (95 Confidence Intervals)(95 Confidence Intervals)
Comorbidity score 0 Ref 1 1 17 (1 08ndash1 28) 1 117 (108 128) 2 or 3 148 (133‐166) 4 or higher 207 (174ndash242)
ChemotherapyChemotherapy No Ref Yes 092 (085ndash100)
Surgeryg y No colectomy Ref Colectomy 151 (131ndash173)
User Group Predominantly Medicare 085 (076ndash095) Dual user Ref Predominantly VA 088 (078ndash099)
Expense rate ratios from GLM model (gamma family with log link) Additional adjusters include hospitals woncology services and outpatient events
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Results Summary
Adjusted costs were lower among single system CC users compared to dual CC userssystem CC users compared to dual CC users
Compared to dual users adjusted costs were Compared to dual users adjusted costs were
15 lower amongg ppredominantlyy Medicare CC users
(ERR 085 CI95 076ndash095)
12 lower among predominantly VA CC users (ERR 088 CI95 078 ndash 099)
26
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Impact on Results
ALTERNATIVE METHODS FOR DEALING WITH OUTLIERS AND INFLUENTIALWITH OUTLIERS AND INFLUENTIAL CASES
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
GLM Models amp LimitationsGLM Models amp Limitations
bull Can accommodate skewness in large bull Can accommodate skewness in large datasets by weighting variances without assumptions regarding distribution assumptions regarding distribution
bull Mis‐specifying variance function in GLMs lt i l i ican result in losses off precision
bull Can lose efficiency if data have large log‐scalle error variance or error ddistribbution on log scale is symmetrical but has a heavy tail
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Colon Cancer Care 12 Month Costs By User Group (N=3842)
Predominantly Predominantly Medicare Dual Use
Predominantly VA
Mean (SD)
Mean (SD)
Mean (SD)
N (SD)
Range N (SD)
Range N (SD)
Range
Total Colon Cancer Cost 1417
39136 (31567)(3 )
(42 ‐ 405892) 510
44264 (50567)( )
(138 ‐ 679471) 1915
36146 (37060)(3 )
(70 ‐ 553115)
I ti tInpatient 1 370 1370 32 907 (29 836)32907 (29836) 492492 42 174 (50 866) 42174 (50866) 1 808 1808 34 587 (37 217)34587 (37217)
Outpatient 1308 7930 (10587) 498 3665 (6347) 1706 3919 (5788)
All significant at Plt001 29
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
ndash
Approaches to Identify Outliers amp Influential Observations
bull AdjAdjusti ting outliers tli ndash Box‐plot analysis
bull Interquartile method bull Interquartile method ndash Winsorization
bull Involves repplacing (or limiting)g) extreme values g (
bull Influential observations ndash Cookrsquos distance
bull Measures the aggregate change with omission DFBETAsDFBETAs
bull Focuses on impact on each regressor
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Characteristics of Each Approach
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
KeKeyy CosCostt DrivDrivererssKeKeyy CosCostt DrivDrivererss
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
LimitationsLimitations
bull S l ti bi th l l i bl (Selection bias three level exposure variable (user group)) not easily amenable to propensity score matching
bull Cases reported from NCI SEER may not represent all the VA reported cases outside VA
bull Coverage in VA and Medicare differs attempted to focus on compparable care ie inppatient and outppatient care
33
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
ConclusionsConclusions Costs were lower for single system users compared to dual
users
These differences were similar using different approaches for accounting for outliers and influential cases
Costs were also higgher among patients who were African g p American had more comorbidities were older or had more advanced‐stage disease
Differences in the course of treatment quality of care and costs attributable to colon cancer warrants further study
34
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
Time for Questions Time for Questions
THANK YOU
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
For Your Reference bull Warren JL Yabroff KR Meekins A et al Evaluation of trends in the cost of initial cancer treatment J Natl Cancer Inst
2008100(12)888‐97
bull Yabroff KR Mariotto AB Feuer E et al Projections of the costs associated with colorectal cancer care in the United States 2000‐2020 Health Econ 200817(8)947‐59
bull Veterans Health Administration VHA Directive 2003‐034 National Cancer Strategy httpwwwvagovvhapublicationsViewPublicationasppub_ID=261
bull Hynes DM Koelling K Stroupe K et al Veterans access to and use of Medicare and Veterans Affairs health care Med Care 200745(3)214‐23
bull Borowsky SJ Cowper DC Dual use of VA and non‐VA primary care J Gen Intern Med 199914(5)274‐80
bull Indurkhya A Gardiner JC Luo Z The effect of outliers on confidence interval procedures for cost‐effectiveness ratios Statistics in Medicine 2001 20 1469‐1477
bull Hynes DM Tarlov E Durazo‐Arvizu R Perrin R Zhang Q Weichle T Ferreira MR Lee T Benson AB Bhoopalam N Bennett CL Surgery and adjjuvant chemotherapypy use among veterans with colon cancer insigghts from a California studyy J Clin Oncol 2010g y g 28 2571‐2576
bull Wagner TH Chen S Barnett PG Using average cost methods to estimate encounter‐level costs for medical‐surgical stays in the VA Med Care Res Rev 2003 60 15S‐36S
bull Phibbs CS Bhandari A Yu W Barnett PG Estimating the costs of VA ambulatory care Med Care Res Rev 2003 60 54S‐73S
bullbull Tukey JL The future of data analysis Ann Math Statist 1962 23 1 67Tukey JL The future of data analysis Ann Math Statist 1962 23 1‐67
bull Barnett V Lewis T Outliers in Statistical Data Third Edition John Wiley amp Sons Chichester England 1994
bull Blough DK Ramsey SD Using Generalized Linear Models to Assess Medical Care Costs Health Services and Outcomes Research Methodology 2000 1 185‐202
bull Mihaylova B Briggs A OHagan A Thompson SG Review of statistical methods for analysing healthcare resources and costs H lth E Health Economiics 2011 2020 897‐9162011 897 916
bull Manning WG Mullahy J Estimating log models to transform or not to transform Journal of Health Economics 2001 20 461‐494
bull Keating NL Landrum MB Lamont EB et al End‐of‐life care for older cancer patients in the Veterans Health Administration versus the private sector Cancer 2010116(15)3732‐9
bull Keating NL Landrum MB Lamont EB et al Quality of care for older patients with cancer in the Veterans Health Administration versus the private sector a cohort study Ann Intern Med 2011154(11)727‐36
