Switching From Retrospective to Current Year Data Collection in the Medical Expenditure

Panel Survey-Insurance Component (MEPS-IC)

Anne T. KearneyU.S. Census Bureau

John P. SommersAgency for Healthcare Research and Quality

ICES III

Session 7

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Important Terms

• Retrospective Design: collects data for the year prior to the collection period

• Current Year Design: collects data in effect at the time of collection

• Survey Year: the year of data being collected in the field

• Single Unit Establishment vs. Multi-Unit Establishment

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Outline

• Background on MEPS-IC

• Why Switch to Current?/Barriers to Switching

• Impact on Frame and Reweighting Methodology

• Details of Current Year Trial Methods

• Results

• Summary

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Background on MEPS-ICGeneral

• Annual establishment survey that provides estimates of insurance availability and costs

• Sample of 42,000 private establishments

• National and state-level estimates

• Retrospective design

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Background on MEPS-ICTiming Example

• Let’s say retrospective design in survey year 2002– Create frame/sample in March 2003 using 2001

data from the business register (BR)– Create SU birth frame with 2002 data from BR– In the field from roughly July-December 2003– Reweighting in March-April 2004 using 2002

data from the BR– Estimation and publication in May-June 2004

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Why Switch to a Current Year Design?

• Estimates published about 1 year sooner• Some establishments report current data already;

current data is at their fingertips • Most survey estimates are conducive to current

year design• Better coverage of businesses that closed after the

survey year and before the field operation• Some data users in favor of going current

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Barriers to Switching to a Current Year Design

• One year older data for frame building

• One year older data for reweightingThese could possibly make our estimates very

different which we believe means worse

• Other data users believe retrospective design is better for collecting certain items

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Impact on Frame

Example: Let’s use 2002 survey year again:

Retrospective Current Year

Create Frame in March 2003 March 2002

SU data available 2001 2001

MU data available 2001 2000

Pick up SU Births? Yes, 2002 No

Drop SU Deaths? Yes, 2002 No

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Impact on ReweightingNonresponse Adjustment

• We use an iterative raking procedure

• We do the NR Adjustment using 3 sets of cells:

– Sector Groups– SU/MU– State by Size Group

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• We use an iterative raking procedure using 2 sets of cells:

– State by Size Group and SU/MU

• Under the retrospective design for the 2002 survey:

Impact on ReweightingPoststratification

i

n

iNR

N

ii

NRPS

EMPAdjwgt

EMPAdjwgtAdjwgt

R

2002_*

2002_*

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Details of Trial Methods

• One issue for frame:– What to do with the births

• One issue for nonresponse adjustment:– What employment data to use for cell assignments

• Three issues for poststratification:– What employment data to use for cell assignments– What employment data to use for total employment– What payroll data to use to create the list of

establishments for total employment

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Details of Trial Methods2002 Survey

Method # Employment Data for Cells/Poststrat

Totals

Inscope List ID’d Using Data from..

Drop Births from

Sample?

SU MU SU MU SU MU

Production 2002 2002 2002 2002 No No

1 2001 2001 2001 2001 No No

2 2002 2001 2001 2001 No No

3 2002 2001 2002 2001 No No

4 2002 2001 2002 2001 Yes No

5 2002 2001 2002 2001 Yes Yes

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Details of Trial Methods2002 Survey

Method # Employment Data for Cells/Poststrat

Totals

Inscope List ID’d Using Data from..

Drop Births from

Sample?

SU MU SU MU SU MU

Production 2002 2002 2002 2002 No No

1 2001 2001 2001 2001 No No

2 2002 2001 2001 2001 No No

3 2002 2001 2002 2001 No No

4 2002 2001 2002 2001 Yes No

5 2002 2001 2002 2001 Yes Yes

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Details of Trial Methods2002 Survey

Method # Employment Data for Cells/Poststrat

Totals

Inscope List ID’d Using Data from..

Drop Births from

Sample?

SU MU SU MU SU MU

Production 2002 2002 2002 2002 No No

1 2001 2001 2001 2001 No No

2 2002 2001 2001 2001 No No

3 2002 2001 2002 2001 No No

4 2002 2001 2002 2001 Yes No

5 2002 2001 2002 2001 Yes Yes

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Details of Trial Methods2002 Survey

Method # Employment Data for Cells/Poststrat

Totals

Inscope List ID’d Using Data from..

Drop Births from

Sample?

SU MU SU MU SU MU

Production 2002 2002 2002 2002 No No

1 2001 2001 2001 2001 No No

2 2002 2001 2001 2001 No No

3 2002 2001 2002 2001 No No

4 2002 2001 2002 2001 Yes No

5 2002 2001 2002 2001 Yes Yes

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Details of Trial Methods2002 Survey

Method # Employment Data for Cells/Poststrat

Totals

Inscope List ID’d Using Data from..

Drop Births from

Sample?

SU MU SU MU SU MU

Production 2002 2002 2002 2002 No No

1 2001 2001 2001 2001 No No

2 2002 2001 2001 2001 No No

3 2002 2001 2002 2001 No No

4 2002 2001 2002 2001 Yes No

5 2002 2001 2002 2001 Yes Yes

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ResultsDefinitions

• National level estimates

• Estimates by firm size– Establishments categorized by their firm

employmentSize Number of Employees

Large 1000+

Medium 50 – 999

Small 1 - 49

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ResultsSurvey Year 2002

Estimate:

% Estabs that offer insurance Prod

Trial Method (Method minus Prod)

1 2 3 5

Natl 57.16 1.22* 1.07* 0.80* 0.45*

L Firm 98.82 -0.06 -0.06 -0.06 -0.04

M Firm 93.65 -0.07 -0.01 0.04 0.08

S Firm 44.72 0.84* 0.67* 0.41* 0.57*

* Indicates significant difference

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ResultsSurvey Year 2002

Estimate: Avg. Single

Premium Prod

Trial Method (Method minus Prod)

1 2 3 5

Natl $3,191 -$5* -$3 -$1 -$4

L Firm $3,136 -$1 $1 $1 -$7

M Firm $3,134 $2 -$4 -$2 -$6

S Firm $3,374 -$25* -$9* -$4 $4

* Indicates significant difference

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ResultsSurvey Year 2003

Estimate:

% Estabs that offer insurance

Prod

Trial Method

(Method minus Prod)

3 5

Natl 56.16 0.72* -0.11

L Firm 98.68 -0.01 0.10

M Firm 90.80 0.10 -0.00

S Firm 43.49 0.64* 0.01* Indicates significant difference

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Summary

• Many positives with going current – timing• Possible frame and reweighting problems

but prior year data are a good substitute• Tested 4 Trial Methods and found:

– Estimates of premiums look good and rates looked reasonable

– Establishment and employment estimates are different but not most important estimates

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Summary (cont.)

• We are planning to switch to a current year design for survey year 2008 using a methodology similar to Method 5.

• We have similar research planned for the governments sample and also plan to continue the research on the private sector with more recent data.

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Anne.Theresa.Kearney@census.gov

John.Sommers@ahrq.hhs.gov