Role of Routine HIV Testing in Concentrated Epidemics Operations Research for Optimizing the HIV...
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Transcript of Role of Routine HIV Testing in Concentrated Epidemics Operations Research for Optimizing the HIV...
Role of Routine HIV Testing in Concentrated Epidemics Operations Research for
Optimizing the HIV Testing Program in an Urban Canadian Setting
K Vasarhelyi, S Kok, JSG Montaner, AR Rutherford, R Barrios, K McPherson, M Thumath, L Tran,
A Nathoo, R Gustafson
Collaboration of Academic and Public Health Partners• BC Centre for Excellence in HIV/AIDS• Vancouver Coastal Health • Providence Health Care • The IRMACS Centre
A poster for the Vancouver Coastal Health / Providence Health Care social marketing campaign promoting routine HIV testing
The IRMACS Centre
The BC Centre for Excellence in HIV/AIDS & Providence Health Care
BACKGROUND
Stakeholder’s Questions
1. Should we do it? Can routine voluntary HIV testing make a useful contribution to controlling the HIV epidemic in Vancouver?2. How can we do it? What is the best way to integrate routine voluntary HIV testing into the current testing program?
The HIV Epidemic in Vancouver• Concentrated epidemic• MSM, IDU, sex workers1 • HIV prevalence ~12 / 10002
• >200 new diagnoses / year in past 10 years3
• <150 new diagnoses in 20123
• HIV testing traditionally risk-based• No routine testing guidelines in Canada
(1) MSM – men who have sex with men; IDU – injection drug user(2) McInnes et al., 2009, Harm Reduction Journal(3) BC Centre for Disease Control (Vancouver’s population 600,000) / Vancouver Coastal Health
Routine Testing
Generalized epidemics
Lower yield
Lower cost/test
Risk-based Testing
Concentrated epidemics
Higher yield
Higher cost/test
What is the optimal mix of testing methods for Vancouver?
Routine Testing
Generalized epidemics
Lower yield
Lower cost/test
Risk-based Testing
Concentrated epidemics
Higher yield
Higher cost/test
YIELD COST
What is the optimal mix of testing methods for Vancouver?
What is the optimal mix of testing methods for Vancouver?
Objectives
• Minimize morbidity• Minimize mortality• Minimize HIV incidence
What is the optimal mix of testing methods for Vancouver?
Objective
• Minimize morbidity• Minimize mortality• Minimize HIV incidence
Operations Research and Optimization
• Find best intervention to meet objective• Intervention is resource allocation• Optimal distribution of new resources• Optimal realignment of existing resources
MODEL
Model DevelopmentStep 1
Qualitative Model for Cascade of Care
Step 2 Qualitative Model for
HIV Testing Program
Step 4System Dynamics / HIV Transmission Simulation Model of Cascade of Care
with Detailed HIV Testing Program
Step 3Combine
Model DevelopmentStep 1
Qualitative Model for Cascade of Care
Step 2 Qualitative Model for
HIV Testing Program
Step 4System Dynamics / HIV Transmission Simulation Model of Cascade of Care
with Detailed HIV Testing Program
Step 3Combine
General Population
MSM
Other Key Populations (IDU, Sex workers)
Qualitative Model of the Cascade of Care
Decisions and activities in the HIV care continuum defined through consultations with system experts
Qualitative Model of the Cascade of Care
Decisions and activities in the HIV care continuum defined through consultations with system experts
DIAGNOSISLINKAGE
TOCARE
RETENTIONIN
CARE
Qualitative Model of the HIV Testing Program
Vancouver Coastal Health for STOP HIV/AIDS Project, Vancouver, Canada (2013)
Qualitative Model of the HIV Testing Program
Vancouver Coastal Health for STOP HIV/AIDS Project, Vancouver, Canada (2013)
Routine Testing inHOSPITALS
HIV Testing Resources
• No $ estimate available• Cost of 1 Risk-Based Test > Cost of 1 Routine Test• Considered 1:1 to 9:1 cost ratios
Number of Tests / Month
Total HIV Testing Resources
+Cost Ratio
RESULTS
Question 1Is routine testing effective in reducing
HIV incidence in Vancouver?
SIMULATON SCENARIO1. Increase total testing budget by 50%.2. Invest all new resources in one program:• Risk-based testing or• Routine testing in high-prevalence settings or• Routine testing in hospitals
3. Compare 5-year cumulative incidence.
Relative effectiveness of testing programsin reducing 5-year cumulative HIV incidence
Risk-based TestingUp to 83 infections averted in 5 years
Routine Testing in HospitalsUp to 104 infections averted in 5 years
Routine Testing inHigh-Prevalence SettingsUp to 274 infections averted in 5 years
Question 2How many infections would be averted by increasing routine testing in hospitals and
improving engagement in treatment?SIMULATION SCENARIO
1. Increase total testing budget by 50%.2. Invest all new resources in routine testing in
hospitals.3. Increase immediate treatment initiation after linkage
to care from 38% to 75% and reduce loss to follow-up from 26% to 10%.
4. Compare 5-year cumulative incidence.
Test Cost RatioRisk-based :Routine
Infections AvertedOver 5 Years Change in
Infections AvertedBaseline
EngagementImproved
Engagement
1:1 41 81 + 98 %
5:1 79 121 + 53 %
9:1 104 147 + 41%
Increasing routine testing in hospitals and improving engagement in treatment
Question 3How many infections would be averted by realigning existing resources between risk-
based and routine testing in hospitals?
SIMULATION SCENARIO
1. Keep total testing budget the same.2. Realign existing resources between risk-based
testing and routine testing in hospitals in 5% increments.
3. Compare 5-year cumulative incidence.
Optimal resource allocation to risk-based testing and routine testing in hospitals to
minimize HIV incidence
Cost Ratio
% Resources in Routine Testing
in Hospitals
Optimal % Hospital
Admissions to Test
(Current=12%)Current Optimal
1:1 38% 0% 0%
3:1 17% 15% 10%
5:1 11% 30% 32%
7:1 8% 40% 59%
9:1 6% 45% 83%
Optimal resource allocation to risk-based testing and routine testing in hospitals to
minimize HIV incidence
Cost Ratio
% Resources in Routine Testing
in Hospitals
Optimal % Hospital
Admissions to Test
(Current=12%)Current Optimal
1:1 38% 0% 0%
3:1 17% 15% 10%
5:1 11% 30% 32%
7:1 8% 40% 59%
9:1 6% 45% 83%
CONCLUSIONS
Conclusions
• Routine HIV testing in Vancouver is likely to be averting infections, especially in high-prevalence settings. In general routine testing may play an important role in controlling concentrated HIV epidemics.
• Optimizing across the cascade of care could avert additional infections.
• Realigning existing resources may improve efficiency of the testing program.
Conclusions
• Next steps include – Morbidity and mortality as optimization objectives – Developing other parts of the model of cascade
• Operations research and optimization provide powerful methods to inform implementation of WHO guidelines on early treatment initiation.
Collaborators & SponsorsBC Centre for
Excellence in HIV/AIDSSilvia Guillemi
Guillaume ColleySusan Shurgold
Benita Yip
Vancouver Coastal Health &Providence Health Care
Kendra McPhersonMeaghan Thumath
Lynn TranReka GustafsonAfshan Nathoo
Allison MacbethChris Buchner
Val MunroeJat Sandhu
Ellen DemlowTim Chu
Scott Harrison
BC Centre for Disease Control
Mark GilbertTravis Salway Hottes
Gina Ogilvie
University of Zurich
Lukas Ahrenberg
IRMACSPam BorghardtPeter Borwein
Brian CorrieFelix Breden
Kelly GardnerAlexa van der Waall
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