Utility of an overlapping panel design in the MEPS Steven B. Cohen, Ph.D.

Presentation Need for essential data on health insurance coverage to inform health care policy and practice Need for essential data on health insurance coverage to inform health care policy and practice Description of the Medical Expenditure Panel Survey (MEPS): purpose, overlapping panel design and analytical capacity Description of the Medical Expenditure Panel Survey (MEPS): purpose, overlapping panel design and analytical capacity Nonresponse and post-stratification adjustments Nonresponse and post-stratification adjustments Recent survey design modifications: Recent survey design modifications: (1) CAPI upgrade; (2) Sample Redesign Evaluation of impact of design modifications on coverage estimates Evaluation of impact of design modifications on coverage estimates Impact of design modifications on model-based analyses of coverage Impact of design modifications on model-based analyses of coverage Discussion Discussion

Medical Expenditure Panel Survey (MEPS) Annual Survey of 14,000 households: provides national estimates of health care use, expenditures, insurance coverage, sources of payment, access to care and health care quality Permits studies of: Distribution of expenditures and sources of payment Distribution of expenditures and sources of payment Role of demographics, family structure, insurance Role of demographics, family structure, insurance Expenditures for specific conditions Expenditures for specific conditions Trends over time Trends over time

HC - Purpose Estimates annual health care use and expenditures Estimates annual health care use and expenditures Provides distributional estimates Provides distributional estimates Supports person and family level analysis Supports person and family level analysis Tracks changes in insurance coverage and employment Tracks changes in insurance coverage and employment Longitudinal design; linkage to National Health Interview Survey (NHIS) Longitudinal design; linkage to National Health Interview Survey (NHIS)

Key Features of MEPS-HC Survey of U.S. civilian noninstitutionalized population Survey of U.S. civilian noninstitutionalized population Sub-sample of respondents to the National Health Interview Survey (NHIS) Sub-sample of respondents to the National Health Interview Survey (NHIS) Oversample of minorities and other target groups Oversample of minorities and other target groups Panel Survey – new panel introduced each year Panel Survey – new panel introduced each year – Continuous data collection over 2 ½ year period – 5 in-person interviews (CAPI) – Data from 1st year of new panel combined with data from 2nd year of previous panel

6 MEPS Panel Design: Data Reference Periods Q1Q2Q3Q4Q1Q2Q3Q4Q1Q2Q3Q4 Panel 10 Round 3 Round 3 Round 4 Round 4 Round 5 Round 5 Panel 11 Round 1 Round 1 Round 2 Round 2 Round 3 Round 3 Round 4 Round 4 Round 5 Round 5 Panel 12 Round 1 Round 1 Round 2 Round 2 Round 3 Round 3 Round 4 Round 4 Round 5 Round 5 Panel 13 Round 1 Round 1 Round 2 Round 2 Round 3 Round 3 Sample Size Sample Size N = 32,577 N = 29,370 N =31,262 N is equal to the number of people with a positive person weight on the file.

MEPS Overlapping Panels (Panels 13 and 14) MEPS Household Component MEPS Panel Round 2Round 3Round 4Round 5 Round 1Round 2Round 3 MEPS Panel /1/20081/1/2009 Round 1 NHIS2007 NHIS2008 Round 4Round 5

Research on Health Insurance Tracks overall health insurance status of the U.S. population Tracks overall health insurance status of the U.S. population – Estimates of uninsured by population characteristics – Duration of spells of uninsurance – Trends in estimates of the uninsured More focused research examines More focused research examines – Factors associated with insurance take up – Financial consequences of being uninsured – Relationship between uninsurance and health status

MEPS Response Rates Multiplicative response rates (RR): product of Multiplicative response rates (RR): product of  NHIS RR and  MEPS RR (multiplicative function of round specific RR): MEPS rounds 1-3 of panel (YR1 estimates) MEPS rounds 1-3 of new panel (YR1 estimates) MEPS rounds 3-5 of panel (YR2 estimates) MEPS rounds 3-5 of old panel (YR2 estimates)

MEPS Response Rates (RR) Overall annual RR (~65%) Overall annual RR (~65%) Highest RR 1 st year, new panel (~66-71%) Highest RR 1 st year, new panel (~66-71%) Lowest RR 2 nd year, old panel (~63-65%) Lowest RR 2 nd year, old panel (~63-65%) Post-survey nonresponse adjustments Post-survey nonresponse adjustments – Dwelling unit level – Person level survey attrition

NHIS variables used as potential covariates in forming DU NR adjustment cells Demographic Household Characteristic Socio- Economic Status GeographicHealth Age DU size Poverty status Census region Health status Race/ethnicity Has phone Education MSA size Need help Marital status Working/reason not work (e.g., attending school, retired, etc,) IncomeMSA/nonMSA Gender Type of PSU Employment status Urban/Rural Any Asian Any Black

NEW NHIS variables added as potential covariates in forming DU NR adjustment cells Demographic Household Characteristic Socio- Economic Status Health Interview language Type of home – house, Apt., etc. Category of medical expense Number of nights in hospital U.S. Citizenship Time no phone Home ownership Healthcare coverage Born in US

Adjustment factor Within each adjustment cell: Within each adjustment cell: A(c) = ratio of the sum of weights of all eligible (E) units in the cell to the sum of weights of only the respondents (R) in the cell

Person Level Adjustments: Annual Estimates Each panel weighted separately Each panel weighted separately Nonresponse adjustment for survey attrition Nonresponse adjustment for survey attrition Final Poststratification adjustment – CPS 12/31: Final Poststratification adjustment – CPS 12/31: age, race/ethnicity, sex, region, MSA status, poverty status age, race/ethnicity, sex, region, MSA status, poverty status

Person Level (survey attrition) Nonresponse Adjustment Covariates Factors associated with survey attrition (after R1) Factors associated with survey attrition (after R1) – Indicator for initial refusal to R1interview – Family size – Age – MSA, census region – Marital status (family reference person) – Race/ethnicity – Education of reference person – Employment status – Health insurance status – Total expenditures (in yr 1 for yr 2 adj.) – # doctor visits (in yr 1) – Self reported health status

Round 1Round 2Round 3Round 4Round Longitudinal Estimation Strategy Individuals in the 2009 sample with positive weights that left the civilian population prior to 2010, with no return 2009 sample also responding in 2010 with complete information for both 2009 and 2010 &

MEPS Definition and estimation of uninsured Types of estimates of uninsured – calendar year focus: Types of estimates of uninsured – calendar year focus: 1. First half of calendar year 2. Annual profiles 3. Two consecutive years 4. Point in time 5. Long-term uninsured: 4 consecutive years As a longitudinal survey MEPS can examine health insurance dynamics, changes in coverage, and spells without insurance As a longitudinal survey MEPS can examine health insurance dynamics, changes in coverage, and spells without insurance

MEPS, 1996–2007: Number of uninsured, under age 65 Number in millions Source: Center for Financing, Access, and Cost Trends, AHRQ, Household Component of the Medical Expenditure Panel Survey, 1996–2006 Full-Year Files and 1996–2007 Point-in-Time Files

MEPS Redesign in 2007 Re-engineered CAPI Interview: Windows-based Platform replaces DOS-based system for Panel 12 Re-engineered CAPI Interview: Windows-based Platform replaces DOS-based system for Panel 12 New NHIS Sample Design Introduced in 2006: MEPS Panel 12 selected from redesigned NHIS sample New NHIS Sample Design Introduced in 2006: MEPS Panel 12 selected from redesigned NHIS sample Year 2 of MEPS Panel 11 based on original MEPS survey design Year 2 of MEPS Panel 11 based on original MEPS survey design The overlapping panel structure in MEPS allows for a comparison of survey estimates across the alternative designed for the same time period The overlapping panel structure in MEPS allows for a comparison of survey estimates across the alternative designed for the same time period

Evaluation of Concordance of Health Insurance Coverage Estimates: Comparison of results from new and original designs MEPS has overlapping panel design: 1st year of new panel combined with data from 2nd year of previous year’s panel to yield annual data MEPS has overlapping panel design: 1st year of new panel combined with data from 2nd year of previous year’s panel to yield annual data Multiplicative response rates: product of NHIS RR and MEPS RR (multiplicative function of round specific RR: 3 rounds for new panel/5 rounds for old panel) Multiplicative response rates: product of NHIS RR and MEPS RR (multiplicative function of round specific RR: 3 rounds for new panel/5 rounds for old panel) Detailed adjustments for survey nonresponse and poststratification: Detailed adjustments for survey nonresponse and poststratification: Compare 2007 coverage estimates based on new design (MEPS Panel 12 – Year 1) with original design (MEPS Panel 11-Year 2) Compare 2007 coverage estimates based on new design (MEPS Panel 12 – Year 1) with original design (MEPS Panel 11-Year 2)

Testing for Survey Redesign Effects Comparisons of panel specific national health insurance coverage estimates for the population under age 65: calendar year: 1) some private coverage during the calendar year, 2) public-only coverage during the year, and 3) full year uninsured calendar year: 1) some private coverage during the calendar year, 2) public-only coverage during the year, and 3) full year uninsured first part of a calendar year: 1) some private coverage, 2) public-only coverage, and 3) uninsured first part of a calendar year: 1) some private coverage, 2) public-only coverage, and 3) uninsured Model-based tests for survey redesign effects Model-based tests for survey redesign effects

Factors associated with health insurance coverage status – Age – MSA, census region – Gender – Marital status – Race/ethnicity – Education – Employment status – Income – Prior Health insurance status – Family size – Country of birth – Self reported health status

Testing for Panel Effect

Comparisons of stability of estimates across surveys Using two sources of national longitudinal data: –Compare national estimates of health insurance status during a 24-month period –Provide insights into reasons for similarities and differences between estimates

Data for longitudinal comparisons Two data sources: NHIS-MEPS linked file using NHIS (Year 1) and the first year of MEPS (Year 2) MEPS longitudinal file using the first year of MEPS (Year 1) and the second year of MEPS (Year 2) Year 1= 2002 and Year 2 = 2003 (analysis repeated with Year 1= 2001 and Year 2 = 2002)

Methods Multinomial regression: identify factors associated with 2-year insurance status (uninsured vs. insured, discontinuous vs. insured) Correlates: age, gender; race/ethnicity; health status, poverty status, residence in a metropolitan statistical area (MSA); and whether born in the U.S.

Insurance status over 24 month period for persons < age 65, Uninsured two yearsInsured two years Percent

Insurance status over 24 month period for persons < age 65, Uninsured two yearsInsured two years Percent

Insurance status over 24 month period for persons < age 65, Uninsured two yearsInsured two years Percent

Regression results for association with being uninsured vs. insured during 24 months, NHIS-MEPS Coefficient Age Sign p-value <18 - < < <.01 MEPS-MEPS Coefficient Sign p-value - < < <.05 Male + < <.001 Hispanic + <.001 Black + ns + < ns Income (% pov) <100% + < <200% + < <400% + < <.001

Design differences that may help explain findings NHIS vs. MEPS 1) Cross-sectional survey with single interview vs. longitudinal survey with five interviews 2) Time period is in reference to interview date vs. calendar year 3) Uninsured “more than 12 months” vs. 12 months MEPS-MEPS file vs. NHIS-MEPS file No gap between “years 1 and 2” vs month gap

Summary Need for accurate and reliable national data on health insurance coverage to inform policy and practice Need for accurate and reliable national data on health insurance coverage to inform policy and practice MEPS design features and analytical capacity MEPS design features and analytical capacity -Emphasis on overlapping panel design Statistical, methodological and operational design features to adjust for nonresponse and attrition Statistical, methodological and operational design features to adjust for nonresponse and attrition Evaluation of impact MEPS redesign on coverage estimates Evaluation of impact MEPS redesign on coverage estimates Impact on model based studies Impact on model based studies