Switching From Retrospective to Current Year Data Collection in the Medical Expenditure Panel Survey-Insurance Component (MEPS-IC) Anne T. Kearney U.S. Census Bureau John P. Sommers Agency for Healthcare Research and Quality ICES III Session 7

2 2 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

3 3 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

4 4 Background on MEPS-IC General Annual establishment survey that provides estimates of insurance availability and costs Sample of 42,000 private establishments National and state-level estimates Retrospective design

5 5 Background on MEPS-IC Timing 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

6 6 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

7 7 Barriers to Switching to a Current Year Design One year older data for frame building One year older data for reweighting These could possibly make our estimates very different which we believe means worse Other data users believe retrospective design is better for collecting certain items

8 8 Impact on Frame Example:Let’s use 2002 survey year again: RetrospectiveCurrent Year Create Frame inMarch 2003March 2002 SU data available2001 MU data available Pick up SU Births?Yes, 2002No Drop SU Deaths?Yes, 2002No

9 9 Impact on Reweighting Nonresponse 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

10 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 Reweighting Poststratification

11 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

12 Details of Trial Methods 2002 Survey Method #Employment Data for Cells/Poststrat Totals Inscope List ID’d Using Data from.. Drop Births from Sample? SUMUSUMUSUMU Production 2002 No No No No YesNo Yes

13 Details of Trial Methods 2002 Survey Method #Employment Data for Cells/Poststrat Totals Inscope List ID’d Using Data from.. Drop Births from Sample? SUMUSUMUSUMU Production 2002 No No No No YesNo Yes

14 Details of Trial Methods 2002 Survey Method #Employment Data for Cells/Poststrat Totals Inscope List ID’d Using Data from.. Drop Births from Sample? SUMUSUMUSUMU Production 2002 No No No No YesNo Yes

15 Details of Trial Methods 2002 Survey Method #Employment Data for Cells/Poststrat Totals Inscope List ID’d Using Data from.. Drop Births from Sample? SUMUSUMUSUMU Production 2002 No No No No YesNo Yes

16 Details of Trial Methods 2002 Survey Method #Employment Data for Cells/Poststrat Totals Inscope List ID’d Using Data from.. Drop Births from Sample? SUMUSUMUSUMU Production 2002 No No No No YesNo Yes

17 Results Definitions National level estimates Estimates by firm size –Establishments categorized by their firm employment SizeNumber of Employees Large1000+ Medium50 – 999 Small1 - 49

18 Results Survey Year 2002 Estimate: % Estabs that offer insurance Prod Trial Method (Method minus Prod) 1235 Natl *1.07*0.80*0.45* L Firm M Firm S Firm *0.67*0.41*0.57* * Indicates significant difference

19 Results Survey Year 2002 Estimate: Avg. Single Premium Prod Trial Method (Method minus Prod) 1235 Natl $3,191-$5*-$3-$1-$4 L Firm $3,136-$1$1 -$7 M Firm $3,134$2-$4-$2-$6 S Firm $3,374-$25*-$9*-$4$4 * Indicates significant difference

20 Results Survey Year 2003 Estimate: % Estabs that offer insurance Prod Trial Method (Method minus Prod) 35 Natl *-0.11 L Firm M Firm S Firm *0.01 * Indicates significant difference

21 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

22 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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