yyyyy yyyyy Report 11

Sample Design of the 1997 Medical Expenditure

Panel Survey Household Component

Methodology Methodology 

U.S. Department of Health and Human Services

Public Health Service

Agency for Healthcare Research and Quality

Agency for Healthcare Research and Quality
  yyyy yyyy

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Abstract

The Medical Expenditure Panel Survey (MEPS) is

the third in a series of nationally representative surveys

of medical care use and expenditures sponsored by the

Agency for Healthcare Research and Quality (AHRQ).

MEPS comprises four component surveys. The

Household Component (HC) produces national and

regional estimates of the health care use, expenditures,

sources of payment, and insurance coverage of the U.S.

civilian noninstitutionalized population. This report gives

a detailed description of the 1997 HC. (The 1996 HC

was described in an earlier report.) The survey’s

overlapping panel design is emphasized. The sample

selection scheme implemented to oversample selected

subgroups—functionally impaired adults, children with

activity limitations, working-age adults predicted to incur

high medical expenditures, and persons predicted to have

low family income—is explained. The report also

includes a summary of sample size specifications, survey

response rates, and targeted precision levels for national

population estimates and health care expenditure

estimates for policy-relevant subgroups.

Suggested citation

Cohen SB. Sample design of the 1997 Medical Expenditure Panel

Survey Household Component. Rockville (MD):Agency for

Healthcare Research and Quality; 2000. MEPS Methodology Report

No. 11.AHRQ Pub. No. 01-0001.

http://www.ahrq.gov/ http://www.ahrq.gov/
  yyyyy yyyyy Report 11

Sample Design of the 1997 Medical Expenditure

Panel Survey Household Component

U.S. Department of Health and Human Services

Public Health Service

Agency for Healthcare Research and Quality

Methodology Methodology 

AHRQ Pub. No. 01-0001

November 2000
The Medical Expenditure Panel

Survey (MEPS)

Background

The Medical Expenditure Panel Survey (MEPS) is

conducted to provide nationally representative estimates

of health care use, expenditures, sources of payment,

and insurance coverage for the U.S. civilian

noninstitutionalized population. MEPS also includes a

nationally representative survey of nursing homes and

their residents. MEPS is cosponsored by the Agency for

Healthcare Research and Quality (AHRQ), formerly the

Agency for Health Care Policy and Research, and the

National Center for Health Statistics (NCHS).

MEPS comprises four component surveys: the

Household Component (HC), the Medical Provider

Component (MPC), the Insurance Component (IC), and

the Nursing Home Component (NHC). The HC is the

core survey, and it forms the basis for the MPC sample

and part of the IC sample. The separate NHC sample

supplements the other MEPS components. Together

these surveys yield comprehensive data that provide

national estimates of the level and distribution of health

care use and expenditures, support health services

research, and can be used to assess health care policy

implications.

MEPS is the third in a series of national probability

surveys conducted by AHRQ on the financing and use

of medical care in the United States. The National

Medical Care Expenditure Survey (NMCES) was

conducted in 1977, the National Medical Expenditure

Survey (NMES) in 1987. Beginning in 1996, MEPS

continues this series with design enhancements and

efficiencies that provide a more current data resource to

capture the changing dynamics of the health care

delivery and insurance system.

The design efficiencies incorporated into MEPS are

in accordance with the Department of Health and

Human Services (DHHS) Survey Integration Plan of

June 1995, which focused on consolidating DHHS

surveys, achieving cost efficiencies, reducing respondent

burden, and enhancing analytical capacities. To

accommodate these goals, new MEPS design features

include linkage with the National Health Interview

Survey (NHIS), from which the sample for the MEPS

HC is drawn, and enhanced longitudinal data collection

for core survey components. The MEPS HC augments

NHIS by selecting a sample of NHIS respondents,

collecting additional data on their health care

expenditures, and linking these data with additional

information collected from the respondents’ medical

providers, employers, and insurance providers.

Household Component

The MEPS HC, a nationally representative survey

of the U.S. civilian noninstitutionalized population,

collects medical expenditure data at both the person and

household levels. The HC collects detailed data on

demographic characteristics, health conditions, health

status, use of medical care services, charges and

payments, access to care, satisfaction with care, health

insurance coverage, income, and employment.

The HC uses an overlapping panel design in which

data are collected through a preliminary contact

followed by a series of five rounds of interviews over a

21⁄

2-year period. Using computer-assisted personal

interviewing (CAPI) technology, data on medical

expenditures and use for 2 calendar years are collected

from each household. This series of data collection

rounds is launched each subsequent year on a new

sample of households to provide overlapping panels of

survey data and, when combined with other ongoing

panels, will provide continuous and current estimates of

health care expenditures.

The sampling frame for the MEPS HC is drawn

from respondents to NHIS, conducted by NCHS. NHIS

provides a nationally representative sample of the U.S.

civilian noninstitutionalized population, with

oversampling of Hispanics and blacks.

Medical Provider Component

The MEPS MPC supplements and validates

information on medical care events reported in the

MEPS HC by contacting medical providers and

pharmacies identified by household respondents. The

MPC sample includes all hospitals, hospital physicians,

home health agencies, and pharmacies reported in the

HC. Also included in the MPC are all office-based

physicians: 

• Providing care for HC respondents receiving

Medicaid.

ii
iii

• Associated with a 75-percent sample of households

receiving care through an HMO (health maintenance

organization) or managed care plan.

• Associated with a 25-percent sample of the

remaining households.

Data are collected on medical and financial

characteristics of medical and pharmacy events reported

by HC respondents, including:

• Diagnoses coded according to ICD-9 (9th Revision,

International Classification of Diseases) and DSMIV (Fourth Edition, Diagnostic and Statistical

Manual of Mental Disorders).

• Physician procedure codes classified by CPT-4

(Current Procedural Terminology, Version 4).

• Inpatient stay codes classified by DRG (diagnosisrelated group).

• Prescriptions coded by national drug code (NDC),

medication names, strength, and quantity dispensed.

• Charges, payments, and the reasons for any

difference between charges and payments.

The MPC is conducted through telephone

interviews and mailed survey materials.

Insurance Component

The MEPS IC collects data on health insurance

plans obtained through private and public-sector

employers. Data obtained in the IC include the number

and types of private insurance plans offered, benefits

associated with these plans, premiums, contributions by

employers and employees, and employer characteristics.

Establishments participating in the MEPS IC are

selected through three sampling frames:

• A list of employers or other insurance providers

identified by MEPS HC respondents who report

having private health insurance at the Round 1

interview.

• A Bureau of the Census list frame of private-sector

business establishments.

• The Census of Governments from the Bureau of the

Census.

To provide an integrated picture of health insurance,

data collected from the first sampling frame (employers

and other insurance providers) are linked back to data

provided by the MEPS HC respondents. Data from the

other three sampling frames are collected to provide

annual national and State estimates of the supply of

private health insurance available to American workers

and to evaluate policy issues pertaining to health

insurance. Beginning in 2000, national estimates of

employer contributions to group health insurance from

the MEPS IC are being used in the computation of

Gross Domestic Product (GDP) by the Bureau of

Economic Analysis.

The MEPS IC is an annual panel survey. Data are

collected from the selected organizations through a

prescreening telephone interview, a mailed

questionnaire, and a telephone followup for

nonrespondents.

Nursing Home Component

The 1996 MEPS NHC was a survey of nursing

homes and persons residing in or admitted to nursing

homes at any time during calendar year 1996. The NHC

gathered information on the demographic

characteristics, residence history, health and functional

status, use of services, use of prescription medications,

and health care expenditures of nursing home residents.

Nursing home administrators and designated staff also

provided information on facility size, ownership,

certification status, services provided, revenues and

expenses, and other facility characteristics. Data on the

income, assets, family relationships, and caregiving

services for sampled nursing home residents were

obtained from next-of-kin or other knowledgeable

persons in the community.

The 1996 MEPS NHC sample was selected using a

two-stage stratified probability design. In the first stage,

facilities were selected; in the second stage, facility

residents were sampled, selecting both persons in

residence on January 1, 1996, and those admitted during

the period January 1 through December 31.

The sampling frame for facilities was derived from

the National Health Provider Inventory, which is

updated periodically by NCHS. The MEPS NHC data

were collected in person in three rounds of data

collection over a 11⁄

2-year period using the CAPI system.

Community data were collected by telephone using

computer-assisted telephone interviewing (CATI)

technology. At the end of three rounds of data collection,

the sample consisted of 815 responding facilities, 3,209

residents in the facility on January 1, and 2,690 eligible

residents admitted during 1996.
iv

     yyyyy yyyyy yyyyy yyyyy yyyyy Public Health Service Act. They are edited and

Survey Management

MEPS data are collected under the authority of the

yyyyy

published in accordance with the confidentiality

provisions of this act and the Privacy Act. NCHS

provides consultation and technical assistance.

As soon as data collection and editing are

completed, the MEPS survey data are released to the

public in staged releases of summary reports and

microdata files. Summary reports are released as printed

documents and electronic files. Microdata files are

released on CD-ROM and/or as electronic files.

Printed documents and CD-ROMs are available

through the AHRQ Publications Clearinghouse. Write or

call:

AHRQ Publications Clearinghouse

Attn: (publication number)

P.O. Box 8547

Silver Spring, MD 20907

800-358-9295

410-381-3150 (callers outside the United States only)

888-586-6340 (toll-free TDD service; hearing 

impaired only)

Be sure to specify the AHRQ number of the

document or CD-ROM you are requesting. Selected

electronic files are available through the Internet on the

AHRQ Web site: 

http://www.ahrq.gov/

On the AHRQ Web site, under Data and Surveys,

click the MEPS icon.

Additional information on MEPS is available from

the MEPS project manager or the MEPS public use data

manager at the Center for Cost and Financing Studies,

Agency for Healthcare Research and Quality, 2101 East

Jefferson Street, Suite 500, Rockville, MD 20852 

(301-594-1406).
v

.Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Sample Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Sample Selection for 1997 MEPS Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Procedures for Data Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Sample Yields and Survey Response Rates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Tables showing statistics for the 1997 MEPS Household Component:

1. Targeted average relative standard errors for subpopulations of analytic interest. . . . . . . . . . . . . . . . . . . 5

2. Targeted sample yields at the end of three core data collection rounds for 1997 

for subpopulations of analytic interest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3. National Health Interview Survey (NHIS) dwelling unit sample classifications 

available for MEPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4. NHIS reporting unit sample classifications available for MEPS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

5. NHIS person-level sample classifications available for MEPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

6. NHIS person-level sample selected for MEPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

7. Sample yields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

8. Sample yields for full-year respondents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Figures showing:

1. Overlapping panel design for point-in-time estimates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2. Overlapping panel design for full-year estimates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

1

Introduction

The Household Component of the 1997 Medical

Expenditure Panel Survey (MEPS) was designed to

produce national and regional estimates of the health

care use, expenditures, sources of payment, and

insurance coverage of the U.S. civilian

noninstitutionalized population. MEPS includes surveys

of medical providers, employers, and other health

insurance providers to supplement the data provided by

household respondents. The MEPS design permits both

person-based and family-level estimates. Government

agencies, legislative bodies, and health professionals

need comprehensive national estimates to use in

formulating and analyzing national health policies. The

scope and depth of this data collection effort reflect this

need. 

MEPS collects data on the specific health services

that Americans use, how frequently they use them, the

cost of these services, and how they are paid for, as well

as data on the cost, scope, and breadth of private health

insurance held by and available to the U.S. population.

MEPS is unparalleled for the degree of detail in its data.

In addition, through MEPS, the medical expenditures

and health insurance data of survey respondents can be

linked to other characteristics, such as demographic

variables, employment status, economic status, health

status, and use of health services. Moreover, MEPS is

the only national survey that provides a foundation for

estimating the impact of changes in sources of payment

for health services and insurance coverage on different

economic groups or special populations of interest, such

as the poor, the elderly, veterans, the uninsured, and

racial and ethnic minorities. 

MEPS is cosponsored by the Agency for Healthcare

Research and Quality (AHRQ), formerly called the

Agency for Health Care Policy and Research, and the

National Center for Health Statistics (NCHS).

MEPS reflects the first stage of implementation of

the Department of Health and Human Services (DHHS)

Survey Integration Plan, which provides directives

targeted to improve the analytic capacity of programs,

fill major data gaps, and establish a framework in which

DHHS data activities are streamlined and rationalized.

Through this effort, specifically through a linkage to the

National Health Interview Survey (NHIS), MEPS has

achieved a number of significant design improvements

and analytic enhancements (Arnett, Hunter, Cohen, et

al., 1996; J. Cohen, 1997; S. Cohen, 1997; Hunter et al.,

1995). 

In this report, the sample design of the Household

Component of the 1997 MEPS is described in detail.

Particular emphasis is given to the overlapping panel

design that characterizes the survey. Attention is given to

the sample selection scheme implemented to facilitate an

oversample of functionally impaired adults, children

with activity limitations, working-age adults predicted to

incur high medical expenditures, and individuals

predicted to have incomes less than 200 percent of the

poverty level. The report also includes a summary of

sample size specifications, survey response rates, and

targeted precision levels for national population

estimates and health care expenditure estimates for

policy-relevant population subgroups.

Sample Design 

To fill major data gaps identified by DHHS, MEPS

was specified as a continuous survey. The 1997 MEPS

Household Component had an overlapping panel design.

Health care data are collected for each new MEPS

sample (panel) to cover a 2-year period, with the first

two MEPS panels spanning 1996-97 and 1997-98,

respectively. To produce health care estimates for

calendar year 1997, the data are pooled across the two

distinct nationally representative MEPS samples. More

specifically, the 1997 design combines the second year

of the first MEPS panel and the first year of the second

MEPS panel. The National Health Interview Survey

serves as the sampling frame for MEPS. NHIS is an

ongoing annual household survey of approximately

42,000 households (109,000 individuals) conducted by

Sample Design of the 1997 Medical Expenditure Panel

Survey Household Component

by Steven B. Cohen, Ph.D., Agency for Healthcare Research and Quality
NCHS to obtain national estimates on health care use,

health conditions, health status, insurance coverage, and

access to care for the U.S. civilian noninstitutionalized

population. In addition to the cost savings achieved by

using NHIS instead of an independent national screener

sample as the MEPS sampling frame, this design feature

enhances the analytic capacity of the resultant survey

data. Use of the NHIS data in concert with the MEPS

data provides a capacity for longitudinal analyses not

available in the prior national medical expenditure

surveys sponsored by AHRQ (S. Cohen, 1996).

The analytical goals of the 1997 MEPS and budget

constraints required that the sample design for the

Household Component meet the following

requirements.

• The full series of interviews for the pooled MEPS

samples covering calendar year 1997 should be

completed in approximately 13,500 households.

• The sample should be spread over 195 separate areas

to represent the civilian noninstitutionalized

population of the 50 States and the District of

Columbia.

• The sample should yield approximately unbiased

national estimates of the health care parameters

under study and estimates of adequate precision for

the four Census regions.

• The sample should meet predesignated precision

specifications for the following population

subgroups of analytical interest: blacks, Hispanics,

the functionally impaired, children with activity

limitations, individuals predicted to have high

medical expenditures, and persons predicted to have

family income less than 200 percent of the poverty

level. 

The 1996 MEPS Household Component sample

was selected from households that responded to the

1995 NHIS. NHIS is designed to permit the selection of

nationally representative subsamples from any one of

four panels. Furthermore, any individual panel or

combination of panels will provide a nationally

representative sample of households. Each NHIS panel

subsample for a given quarter of a calendar year is

nationally representative. The 1996 MEPS household

sample was selected from two of the four 1995 NHIS

panels during the second and third quarters of 1995.

Consequently, the MEPS sample is an approximately

one-quarter subsample of the overall 1995 NHIS

sample. 

The complete 1995 NHIS sample (panels 1-4)

consists of 358 primary sampling units, or PSUs (which

are counties or groups of contiguous counties), and

approximately 42,000 responding households. The

NHIS sample design is characterized by a stratified

multistage area probability design, with the sample

PSUs stratified by geographic area (Census region and

State), metropolitan status, and sociodemographic

measures (Judkins, Marker, and Waksberg, 1994).

Within sample PSUs, a sample of blocks (segments)

was selected after the blocks were stratified by measures

of minority population density that allowed for an

oversample of areas with high population concentrations

of blacks and Hispanics. A nationally representative

sample of approximately 71,000 addresses within

sampled blocks was selected and targeted for further

screening to facilitate an oversample of blacks and

Hispanics as part of the 1995 NHIS interview. 

The 1995 NHIS subsample selected for the 1996

MEPS consists of 195 PSUs. In the two targeted

quarters of 1995, these PSUs included 1,675 sample

segments (second-stage sampling units) and 10,597

responding households. This NHIS sample reflects

oversampling of households with Hispanics and blacks

at a ratio of approximately 2.0:1 for Hispanics and 1.5:1

for blacks. This 1996 MEPS sample constitutes a panel

that was surveyed to collect annual data for 2

consecutive years (S. Cohen, 1997). 

A new 1997 MEPS panel sample was selected as a

nationally representative subsample of households

responding to the 1996 NHIS. More specifically, this

1997 MEPS sample was selected from the same two

NHIS panels used for the 1996 MEPS, using a

nationally representative subsample of the 1996 NHIS

that also reflected an oversample of Hispanics and

blacks at the same ratios as in the 1995 NHIS

(Hispanics, 2.0:1; blacks, 1.5:1). 

It should be noted that in 1996, NHIS was

undergoing a transition from paper-and-pencil survey

administration to computer-assisted personal

interviewing. The subsample of NHIS reserved for the

1997 MEPS sample selection retained the paper-andpencil survey administration mode to allow for

smoother integration of the two national surveys. 

2
The new 1997 MEPS sample was selected from the

first three quarters of the 1996 NHIS subsample within

the two panels reserved for MEPS. This NHIS

nationally representative subsample was concentrated

within the same 195 PSUs selected for the 1996 MEPS

household sample and consisted of 14,706 responding

NHIS dwelling units. A nationally representative

subsample of 6,300 NHIS responding dwelling units

(consisting of 6,480 reporting units) was selected to

serve as the new 1997 MEPS sample. In addition to

retaining the oversample of minorities that characterized

the NHIS sample design, the 1997 MEPS was designed

to oversample the following policy-relevant subgroups:

functionally impaired adults, children limited in

activities, adults predicted to have high medical

expenditures, and persons predicted to have family

income less than 200 percent of the poverty level. The

new 1997 MEPS panel was designed to collect annual

data for 2 consecutive years. Consequently, the full 1997

MEPS Household Component sample consists of the

first year of the 1997 MEPS panel pooled with the

second year of the 1996 MEPS sample. 

Sampling Unit Definitions and Eligibility

Criteria 

The definitions for dwelling units and group

quarters in the MEPS Household Component are

generally consistent with the definitions employed for

NHIS. More specifically, a dwelling unit is a house,

apartment, group of rooms, or single room occupied as

separate civilian noninstitutional living quarters or

vacant but intended for occupancy as separate living

quarters. Group quarters consist of a single civilian

noninstitutional dwelling or structure in which nine or

more unrelated persons reside and where inhabitants are

not considered a part of any other dwelling unit. A

reporting unit is a person or group of persons in the

sampled dwelling unit who are related by blood,

marriage, adoption, or other family associations and are

to be interviewed at the same time in MEPS. Examples

of discrete reporting units follow. 

• A married daughter and her husband living with her

parents in the same dwelling are considered one

reporting unit. 

• A husband and wife and their unmarried daughter,

age 18, who is living away from home at college

constitute one family, but two reporting units. 

• Three unrelated persons living in the same dwelling

unit would be three reporting units.

College students under 24 years of age who usually live

in the sampled household but are currently living away

from home and going to school are treated as separate

reporting units for the purpose of data collection. 

The new 1997 MEPS sample consisted of

households (dwelling units) that responded to the 1996

NHIS in the two panels reserved for MEPS, with the

basic unit of analysis defined as the person. This

mirrored the 1996 MEPS design. Analysis is planned

using both the individual and the family as units.

Through the reenumeration section of the Round 1

questionnaire for each MEPS panel, the status of each

individual sampled at the time of the NHIS interview is

classified as “key” or “non-key,” “in-scope” or “out-ofscope,” and “eligible” or “ineligible” for MEPS data

collection. For an individual to be in scope and eligible

for person-level estimates derived from the MEPS

household survey, he or she must be a member of the

civilian noninstitutionalized population for some period

of time in the calendar year of analytic interest. Because

a person’s eligibility for the survey may change after the

NHIS interview, sampling reenumeration takes place in

each subsequent reinterview for persons in all

households selected into the core survey. The keyness,

in-scope, and eligibility indicators, together, define the

target sample to be used for person-level national

estimates. Only persons who are key, in scope, and

eligible for data collection are considered in the

derivation of person-level national estimates from

MEPS. 

Key Persons 

Key survey participants are defined as all civilian

noninstitutionalized individuals who resided in

households that responded to the nationally

representative NHIS subsample reserved for MEPS

(e.g., 6,300 households from the 1996 NHIS), with the

exception of college students interviewed at dormitories.

Members of the Armed Forces who are on full-time

active duty are also defined as key persons if they reside

in responding NHIS households that include other

family members who are civilian noninstitutionalized

individuals. However, they are out of scope for personlevel estimates derived from the survey. 

3
4

All individuals who join the NHIS reporting units

that define the 1997 MEPS household sample (in Round

1 or later MEPS rounds) and were not available for

selection during the time of the NHIS interview are also

considered key persons. These include newborn babies,

individuals who were in an institution or outside the

country, and military personnel previously residing on

military bases. 

College students under 24 years of age interviewed

at dormitories in the 1996 NHIS are not included in the

1997 MEPS sample, since this population subgroup will

be targeted through their parents during the MEPS

interview. The same rule applied to the 1996 MEPS

sample selected from the 1995 NHIS. Furthermore, any

unmarried college student under 24 years of age who

responded to the 1996 NHIS interview while living

away at school (not in a dormitory) is excluded from the

sample if it is determined in the MEPS Round 1

interview that the person is unmarried, under 24 years of

age, and a student who has parents living elsewhere and

who resides at his or her current housing only during the

school year. If, on the other hand, the person’s status at

the time of the MEPS Round 1 interview is no longer

that of an unmarried student under 24 years of age

living away from home, then the person is retained as a

key person.

Additionally, during the MEPS Round 1 interview

with NHIS sample respondents, a determination is made

whether there are any related college students under 24

years of age who usually live in the sampled household

but are currently living away from home and going to

school. These college students are considered key

persons and are identified and interviewed at their

college address but linked to the sampled household for

family analyses. Some of these college students will

have been identified as living in the sampled household

at the time of the 1995 NHIS interview. The remainder

are identified at the time of the MEPS Round 1

interview. 

Non-Key Persons 

Persons who were not living in the original sampled

dwelling unit at the time of the relevant NHIS interview

and who had a non-zero probability of selection for that

survey are considered non-key. (The 1996 NHIS

interview is the relevant interview for the 1997 MEPS

sample; the 1995 NHIS interview is the relevant

interview for the 1996 MEPS sample.) If such persons

happen to be living in sampled households in Round 1

or later rounds, MEPS data are collected for the period

of time they are part of the sampled unit to permit

family analyses. Non-key persons who leave any

sampled household are not recontacted for subsequent

interviews. Non-key individuals are not part of the target

sample used to obtain person-level national estimates. 

A key person from the NHIS sampled household

selected for MEPS may move out in Round 1 or later

rounds and join or create another family. Data on all

members of this new household who are related by

blood, marriage, adoption, or foster care to the person

from the NHIS sampled household are obtained from

the time that the sampled person joined the household.

Keyness status (key or non-key) is determined for these

new members based on their probability of selection for

NHIS. If it is positive, they are classified as non-key.

Similarly, data are collected in Round 1 and later rounds

on all related persons who join NHIS sampled

households selected into MEPS. 

Persons in NHIS sampled households selected in

MEPS may subsequently enter an institution, thus no

longer qualifying as a member of the U.S. civilian

noninstitutionalized population. For those who enter

nursing homes, data collection continues during the

nursing home stay. For those who enter other

institutions, data collection is suspended while they are

institutionalized, but their whereabouts are monitored

during the field period. If they rejoin the U.S. civilian

noninstitutionalized population, HC data collection

resumes. (This is also the procedure for those entering

military service away from home or moving out of the

United States.) 

MEPS Data Collection Eligibility 

In order for a MEPS reporting unit to be eligible for

data collection, it must include at least one individual

who is key and in scope for some period of time during

the reference period for a given round of data collection.

If this condition holds, the persons who are key and in

scope and all other individuals who are members of the

reporting unit (living together and related by blood,

marriage, adoption, or other family associations) are

eligible for data collection in a given round of MEPS. 
Table 1.Targeted average relative standard errors (RSEs) for subpopulations of

analytic interest in the 1997 Medical Expenditure Panel Survey Household

Component

Average Average

RSE for a population RSE for mean use

estimate of 20 percent and expenditure

Subpopulation (e.g., percent uninsured) estimates

Persons with family income less than 200 percent

of poverty level .020 .035

Persons ages 18-64 predicted to incur high medical 

expenditures .040 .070

Persons 65 years and over .042 .070

Adults (18 and over) with functional impairments measured

in terms of ADLsa .080 .135

Adults (18 and over) with other impairments measured in 

terms of IADLsb .080 .135

Children (under age 18) with activity limitations .080 .135

Overall population .015 .023

a Need help in 1 or more activities of daily living (ADLs), such as bathing and dressing.

b Need help in 1 or more instrumental activities of daily living (IADLs), such as shopping or paying bills.

Source: Center for Cost and Financing Studies, Agency for Healthcare Research and Quality: Medical Expenditure Panel Survey Household

Component, 1997.

5

Sample Selection for 1997 MEPS

Panel

Sample Size Targets and Precision

Requirements 

An overall precision requirement for the 1997 MEPS

was the achievement of an average design effect of 1.7

for survey estimates of the policy-relevant population

subgroups. The precision requirements for the 1997 HC

are presented in Table 1. They are presented in terms of

relative standard errors for the following survey

estimates.

• A 20-percent population estimate at the person level

for each specified domain (e.g., a percent population

estimate such as the rate of uninsured for the

population under age 65). 

• Mean estimates of the following measures of health

care utilization and expenditures at the person level

(precision requirement specified as an average

relative standard error):

—Total health expenditures.

—Utilization and expenditure estimates for

inpatient hospital stays.

—Utilization and expenditure estimates for

ambulatory physician visits.

—Utilization and expenditure estimates for dental

visits.

—Utilization and expenditure estimates for

prescribed medicines.
6

The 1997 MEPS person-level precision

requirements are specified for estimates derived from

individuals who are considered full-year respondents

(individuals with responses for their entire period of

eligibility in 1997). Consequently, in the determination

of sample sizes necessary to achieve the precision

requirements, additional adjustments must be made for

survey nonresponse to obtain the targeted number of

full-year respondents. Approximately 34,000 persons

completing the three core MEPS household interviews

to cover calendar year 1997 (Rounds 1-3 for the new

1997 MEPS sample; Rounds 3-5 for the carryover 1996

MEPS sample) were targeted for sample selection to

achieve the desired precision specifications for national

population estimates. Assuming 2.5 persons per original

sampled reporting unit, it was estimated that

approximately 13,600 families were needed to complete

the three rounds in 1997 to meet precision

specifications. Table 2 indicates the number of persons

in the various subpopulations of interest needed to

satisfy the survey precision requirements for the pooled

1996 and 1997 MEPS samples to permit 1997

population estimates. 

Precision requirements for the 1997 MEPS HC were

stated in terms of national estimates at the person level.

To meet these requirements, the survey must include a

minimum number of persons in each domain of interest.

The prior 1996 MEPS sample was also selected to

satisfy distinct precision requirements at the person level

for overall population estimates and for subgroup

analyses of blacks and Hispanics for calendar year 1996

(S. Cohen, 1997). To satisfy precision requirements for

the pooled 1997 MEPS sample, the Panel 1 MEPS

yields were derived and projected into 1997. Additional

sample sizes necessary to satisfy the precision

requirements for the analytical domains were determined

(after adjusting for estimated survey nonresponse).

These projected yields informed the specification of the

final sample selection rates for the new 1997 Panel 2

MEPS sample. 

Table 2.Targeted sample yields at the end of three core data collection rounds for

1997 for subpopulations of analytic interest: 1997 Medical Expenditure Panel

Survey Household Component 

Subpopulation Targeted sample yield

Persons with family income less than 200 percent of poverty level 15,000

Persons ages 18-64 predicted to incur high medical expenditures 4,000

Persons 65 years and over 3,700

Adults (18 and over) with functional impairments measured in terms of ADLsa 1,000

Adults (18 and over) with other impairments measured in terms of IADLsb 1,000

Children (under age 18) with activity limitations 1,000

Overall population 34,000

a Need help in 1 or more activities of daily living (ADLs), such as bathing and dressing.

b Need help in 1 or more instrumental activities of daily living (IADLs), such as shopping or paying bills.

Source: Center for Cost and Financing Studies, Agency for Healthcare Research and Quality: Medical Expenditure Panel Survey Household

Component, 1997
7

For both the 1996 and 1997 MEPS, the unit of

interviewing and subsampling was the household. To

facilitate the sample selection of the new 1997 MEPS

sample, the 1996 NHIS households were selected on the

basis of the characteristics of the persons they included.

There were seven sample domains of interest. An NHIS

dwelling unit was assigned to one or more sample

domains based on having at least one household member

with the characteristic of interest:

• Adults (age 18 and over) with functional

impairments—at least one activity of daily living

(ADL) for which assistance is needed.

• Children (under age 18) with limitations in activity.

• Individuals 18-64 years old with predicted high

medical expenditures (predicted probability of .4 or

more, using the MEPS prediction model to identify

likely high-expenditure individuals).

• Individuals with family incomes likely to be below

200 percent of poverty level (predicted probability of

.3 or more, using the MEPS prediction model to

identify low-income households).

• Adults with other impairments—ages 18-69, at least

one instrumental activity of daily living (IADL) and

unable to work; age 70 and over, at least one IADL. 

• Elderly individuals (age 65 and over).

• All remaining individuals.

These sampling domains are not mutually exclusive,

but their order reflects the hierarchy of their sampling

priority. For purposes of sampling, dwelling units

containing members having these characteristics were

hierarchically classified to form seven mutually

exclusive and exhaustive sampling strata (DiGaetano,

1994).

Using Predictive Models for Domain

Assignments

Poverty Status Model

Since a reporting unit’s poverty status classification

in 1997 was unknown at the time the 1996 NHIS

interview was administered, a prediction model was used

to determine whether a household was to be

oversampled. More specifically, a logistic regression

model was developed to estimate the probability that a

reporting unit would have a family income less than 1.25

times the poverty level in a subsequent year, based on

the poverty status classification and other predictive

measures obtained during the NHIS interview.

Households with predicted probabilities above a certain

threshold value were to be oversampled. In addition to

facilitating an oversample of individuals with family

income less than 125 percent of the poverty level, use of

this prediction model was expected to facilitate an

oversample of individuals with family income less than

200 percent of the poverty level. Consequently, all

reporting units with a predicted probability of .3 or

greater were classified as households predicted to have

family income less than 200 percent of the poverty level.

Data from the 1987 National Medical Expenditure

Survey (NMES) were examined using a predicted

probability of .3 or greater (derived from the logistic

regression prediction model) as the criterion to target

reporting units most likely to have members with family

income less than 200 percent of the poverty level in

1996. Based on an evaluation of the model’s

performance at the reporting-unit level, the following

results were observed.

• Among the 19.5 percent of reporting units predicted

to have members with family income less than 200

percent of the poverty level, the expected prediction

rate for true positives (family income less than 200

percent of the poverty level) is 83.1 percent.

• Among the 80.5 percent of reporting units predicted

to have family income at or above 200 percent of the

poverty level, the expected prediction rate for false

negatives is 17.1 percent.

• Among the 30 percent of reporting units with family

income less than 200 percent of the poverty level, 54

percent had been predicted to have members with

family income less than 200 percent of the poverty

level. Alternatively, among the 70 percent of

reporting units with family income at or above 200

percent of the poverty level, 95.3 percent had been

predicted to have members with family income above

200 percent of the poverty level.

The logistic regression model that was adopted was

specified at the reporting unit level and required data on

the following measures obtained in the NHIS interview

(Moeller and Mathiowetz, 1994):

• Age of reference person.

• Home ownership.

• Reporting unit (RU) size.
• Whether children of specific ages (under 6, 6-15) are

present in the RU.

• Whether someone in the RU other than the reference

person is at least 65 years of age.

• Health status of reference person.

• Race/ethnicity of reference person.

• Census Division.

• Metropolitan statistical area (MSA) status of PSU.

• Education of reference person.

• Marital status and sex of reference person.

• Whether reference person or spouse was employed

in the previous 3 months.

• Whether the family income of the reporting unit was

less than 1.25 times the poverty level. 

• Whether anyone in the RU was covered by

Medicaid.

High-Expenditure Prediction Model

Among the sample domains to be oversampled in

the main survey are individuals ages 18-64 who are

predicted to be likely to incur high medical

expenditures. An individual’s medical care expenditures

in a future year were unknown when the 1996 NHIS

interview was administered. Therefore, a prediction

model based on NMES data was used to determine

whether a household should be oversampled as part of

the high-medical-expenditures group because one or

more of the family members were expected to incur

high medical expenditures in the subsequent year. More

specifically, a logistic regression model was developed

to estimate the expected probability that an individual

ages 18-64 will incur high medical expenditures (top 15

percent of the health expenditure distribution) in a

subsequent year based on predictive measures obtained

during the NHIS interview. Households with at least

one person with a predicted probability above a certain

threshold value were oversampled. The group was

restricted to individuals ages 18-64, since persons 65

and over who were functionally impaired were

separately targeted to be oversampled. For purposes of

sampling, all individuals with a predicted probability of

.4 or greater were classified as likely to incur high

medical expenditures in the subsequent year. This

threshold was selected as the value that was expected to

best limit prediction errors. 

The logistic regression model under consideration

was specified at the person level and requires data on

the following measures obtained in the NHIS interview

(Moeller and Mathiowetz, 1994):

• Sex.

• Health status.

• Marital status.

• Poverty status.

• Whether the person lives alone.

• Age.

• Whether the person’s health keeps him or her from

working at a job, doing work around the house, or

going to school.

• Whether the person is unable to do certain kinds or

amounts of work, housework, or schoolwork because

of health.

• The number of visits to a medical doctor or other

medical care provider the person has had during the

last 6 months.

• The number of times prescribed medicines were

purchased or obtained for the person’s use in the last

6 months. (An imputation strategy was used to

derive this measure, since data were unavailable

from the 1996 NHIS.)

• Census Division. 

• MSA status of PSU.

The results listed below were observed based on an

evaluation of the model’s performance at the individual

level, using data from NMES. A predicted probability of

.4 or greater (derived from the logistic regression

prediction model) was used as the criterion to target

individuals who are age 18-64 and considered likely to

incur high medical expenditures in the subsequent year.

• The expected prediction rate for true positives

(computed at the RU level) is 37.7 percent among

the 14.1 percent of individuals in RUs with members

age 18-64 who are predicted to incur high medical

expenditures in the subsequent year. It should be

noted that when the evaluation is restricted to the

subset of individuals predicted to incur high medical

expenditures (8.1 percent), the expected prediction

rate for true positives is 65.3 percent (computed at

the person level).

• The expected prediction rate for false negatives

(computed at the RU level) is 11.3 percent among

the 85.9 percent of individuals in RUs with members

age 18-64 predicted not to incur high medical

expenditures in the subsequent year.

8
9

NHIS Sample Composition

In order to provide the 1997 MEPS sample to

Westat and the National Opinion Research Center (the

MEPS data collection organizations) in the timeframe

specified to field the survey in February 1997, it was

necessary to restrict the sample selection to the

nationally representative NHIS subsample for the first

three quarters of 1996 rather than the entire year. This

NHIS sample of 14,706 responding dwelling units was

then classified into seven mutually exclusive and

exhaustive sampling classes based on the demographic

characteristic of its “highest priority” individual. This

was the household member requiring the highest

sampling rate to meet sample size targets.

The sampling classes presented in Table 3 are

arranged in order of priority. The table provides a

distribution of the 14,706 responding NHIS dwelling

units according to these sampling classes, the MEPS

sampling rates, and the resultant sample of dwelling

units selected for the 1997 MEPS. It should be noted

that a dwelling unit with a higher order sampling

classification may include members with a

characteristic of interest that defines a lower sampling

classification. More specifically, a dwelling unit with a

sampling classification of 1, which indicates that the

dwelling unit includes an adult (age 18 and over) with

functional impairments (at least one ADL requiring

personal assistance), may also include a member with

any of the other characteristics targeted for

oversampling: children (under age 18) with limitations

in activity; individuals 18-64 years old with predicted

high medical expenditures; individuals with family

incomes likely to be below 200 percent of poverty level;

adults with other impairments (age 18-69, at least one

IADL, and unable to work; or age 70 and over and at

least one IADL). However, dwelling units assigned to

sampling classes with lower priority do not include

members with a characteristic that defines a higher

order classification. 

For sampling purposes, a person was classified as

having at least one ADL requiring personal assistance if

there was an affirmative answer to the following

question in the 1996 NHIS: “Because of any

impairment or health problem, does ___ need the help

of other persons with personal care needs, such as

eating, bathing, dressing, or getting around this home?”

Similarly, a person was classified as having at least one

IADL requiring assistance if there was an affirmative

answer to the following question in the 1996 NHIS:

“Because of any impairment or health problem, does

___ need the help of others in handling routine needs,

such as everyday household chores, doing necessary

business, shopping, or getting around for other

purposes?”

Rates of selection were specified to satisfy sample

size targets for the pooled 1997 sample for individuals

with specific characteristics. All NHIS dwelling units

assigned to the first three sampling classes ordered by

sampling priority—adults with functional impairments

(at least one ADL requiring personal assistance),

children (under age 18) with limitations in activity, and

individuals 18-64 years old predicted to incur high

levels of medical expenditures—were selected with

certainty for inclusion in the 1997 MEPS sample.

Dwelling units associated with the next highest priority

sampling classes—individuals with family incomes

predicted to be below 200 percent of poverty level and

adults with other impairments (at least one IADL)—

were then selected at a sampling rate of 0.6. All

remaining dwelling units associated with the remaining

sampling classes were selected with a rate of 0.3.

Prior to sample selection, dwelling units within each

of the sampling classes were hierarchically sorted by the

following measures:

• Quarter of calendar year 1996.

• Week within applicable calendar quarter of 1996.

• Census Division.

• State.

• MSA classification.

• NHIS primary sampling unit.

• NHIS segment within primary sampling unit.

• Minority classification of dwelling unit (Hispanic,

black non-Hispanic, other).

A random systematic sample of dwelling units was

then selected from each sampling class, using the

specified sample selection rate (Table 3). Table 4 shows

the distribution of the 15,067 responding NHIS

reporting units within the dwelling units according to

these sampling classes. It also shows the resultant

sample of 6,480 reporting units selected for the 1997

MEPS. Table 5 shows the distribution of the 38,418

responding NHIS individuals within the dwelling units

assigned to the hierarchically defined sampling classes,

in addition to the subsample of 17,063 individuals

selected for the 1997 MEPS sample. Since individuals
may be classified in more than one category based on

the sampling domains under consideration, the sample

yields for the 1997 MEPS sample, allowing for multiple

classifications, are presented in Table 6. (Note that the

sample distributions presented in Tables 3-6 are

confined to the new panel of MEPS introduced in

1997.)

Procedures for Data Collection 

The preliminary contact with households

responding to NHIS and subsampled as part of a MEPS

panel is described in S. Cohen (1997). Procedures in the

rounds of data collection are described below. 

Five interviews are conducted with each NHIS

panel selected for MEPS at 4- to 5-month intervals over

an approximately 24-month field period. The first three

rounds (Panel 1, Rounds 1-3) define the 1996 MEPS

Household Component and collect the main body of

annual use and expenditure data for calendar year 1996.

Rounds 3-5 of the 1996 MEPS panel (Panel 1, Rounds

3-5) are combined with Rounds 1-3 of the 1997 MEPS

panel (Panel 2, Rounds 1-3) to yield the sample base for

the 1997 MEPS Household Component and the source

of annual estimates for that calendar year. All interviews

are conducted in person through a computer-assisted

personal interview (CAPI). Round 1 asks about the

period from January 1 of the MEPS year to the date of

that interview, Round 2 asks about the time from the

Round 1 interview through the date of the Round 2

interview, and Round 3 asks about the time from the

date of the Round 2 interview through the date of the

Round 3 interview in 1997.

Questionnaires for these field rounds parallel those

used in the 1987 NMES but include some modifications

implemented for a 1992 feasibility study and further

changes stemming from the feasibility study and a

MEPS pretest. The instruments contain items that are

asked once in the life of the study, items that are asked

repeatedly in each round, and items that are updated in

later rounds. Questions asked only once include basic

sociodemographic characteristics. Core questions asked

repeatedly include health status, health insurance

coverage, employment status, days of restricted activity

due to health problems, medical use, hospital

admissions, and purchase of medicines. For each health

encounter identified, data are obtained on the nature of

health conditions, characteristics of the provider,

services provided, associated charges, and sources and

amounts of payment.

Permission forms for medical providers are

collected in the field. A sample of medical providers

identified by MEPS respondents is contacted in the

survey of medical providers—the MEPS Medical

Provider Component, or MPC—to verify and

supplement information provided by the family

respondent in the household interview. Employers and

other health insurance providers are contacted in the

survey of health insurance providers—the MEPS

Insurance Component, or IC—to collect other

10

Table 3. National Health Interview Survey (NHIS) dwelling unit sample

classifications available for the 1997 Medical Expenditure Panel Survey (MEPS)

Household Component

1997 MEPS subsample

1996 NHIS

Sampling class in priority order frequency Frequency Sampling rate

1. Functionally impaired adults 478 478 1.0

2. Children with activity limitations 601 601 1.0

3. Persons 18-64 predicted to incur high medical expenditures 596 596 1.0

4. Low income 2,064 1,238 0.6

5.Adults with other impairments 324 194 0.6

6. Persons 65 and over 2,157 647 0.3

7. Other 8,486 2,546 0.3

Total 14,706 6,300 —

Source: National Center for Health Statistics, Centers for Disease Control and Prevention: National Health Interview Survey, 1996.
Table 5. National Health Interview Survey (NHIS) person-level sample

classifications available for the 1997 Medical Expenditure Panel Survey (MEPS)

Household Component

1996 NHIS 1997 MEPS 

Sampling class in priority order frequency subsample frequency

1. Functionally impaired adults 506 506

2. Children with activity limitations 723 723

3. Persons 18-64 predicted to incur high medical expenditures 701 701

4. Low income 6,304 4,181

5.Adults with other impairments 393 253

6. Persons 65 and over 3,234 1,109

7. Other 26,557 9,590

Total 38,418 17,063

Source: National Center for Health Statistics, Centers for Disease Control and Prevention: National Health Interview Survey, 1996.

11

Table 6. National Health Interview Survey (NHIS) person-level sample selected for

the 1997 Medical Expenditure Panel Survey (MEPS) Household Component

Sampling class in priority order 1997 MEPS subsample frequency

1. Functionally impaired adults 506

2. Children with activity limitations 723

3. Persons 18-64 predicted to incur high medical expenditures 755

4. Low income 7,990

5.Adults with other impairments 900

6. Persons 65 and over 4,600

Source: National Center for Health Statistics, Centers for Disease Control and Prevention: National Health Interview Survey, 1996.

Table 4. National Health Interview Survey (NHIS) reporting unit sample

classifications available for the 1997 Medical Expenditure Panel Survey (MEPS)

Household Component

1996 NHIS 1997 MEPS 

Sampling class in priority order frequency subsample frequency

1. Functionally impaired adults 481 481

2. Children with activity limitations 601 601

3. Persons 18-64 predicted to incur high medical expenditures 600 600

4. Low income 2,126 1,274

5.Adults with other impairments 326 194

6. Persons 65 and over 2,163 652

7. Other 8,770 2,678

Total 15,067 6,480

Source: National Center for Health Statistics, Centers for Disease Control and Prevention: National Health Interview Survey, 1996.
12

information on insurance characteristics that household

respondents would not typically know. 

Sample Yields and Survey

Response Rates

Data to cover a 2-year period are collected for each

MEPS panel. The first two MEPS panels spanned 1996-

97 and 1997-98, respectively. This section provides a

summary of the sample yields for deriving national

person-based estimates from the 1997 MEPS: both

point-in-time estimates (first part of calendar year 1997)

and annual estimates. Attention will first be given to the

point-in-time estimation capacity of the survey, followed

by an emphasis on the sample yields for producing

calendar year health care estimates. 

Point-in-Time Estimates for First Part of

1997

To produce point-in-time health care estimates for

the first part of 1997 based on the MEPS sample

design, data need to be pooled from the first two MEPS

national samples, with data covering approximately the

first half of calendar year 1997. More specifically, data

from the 1997 portion of the third round of data

collection for the MEPS Panel 1 sample are pooled with

data from the first round of data collection for the

MEPS Panel 2 sample (Figure 1). This feature of the

MEPS design supports the derivation of health

insurance coverage estimates covering the first half of

calendar year 1997. 

Panel 1

Initially, in 1996, the MEPS Panel 1 sample

consisted of 10,639 households, a nationally

representative subsample of the households responding

to the 1995 National Health Interview Survey. The

1995 NHIS sampled households with Hispanic

members and households with black members at

approximately 2.0 and 1.5 times the rate of other

households, respectively. These oversampling rates are

also reflected in the MEPS sample of households. The

1995 NHIS response rate for MEPS-eligible households

was 94 percent. Of 10,639 responding NHIS dwelling

units eligible for MEPS, 99.6 percent were identified

with enough information to allow MEPS data

collection. Of the 11,424 eligible reporting units

targeted for interviews in Round 1, 9,488 (83.1 percent)

responded. Overall, the joint (NHIS and MEPS Round

1) response rate for the 1996 MEPS household survey

was 77.7 percent (.939 x .996 x .831). Conditioned on

participation in MEPS, 90.33 percent of the sample

participants provided data for their entire period of

eligibility in 1996 and through the early part of 1997

(Round 3). Consequently, the overall MEPS Panel 1

response rate at the end of Round 3 (which collects data

for the first part of 1997) was 70.2 percent, reflecting

response to the 1995 NHIS interview and the MEPS

interviews for Rounds 1-3 (S. Cohen, 1997). Overall,

the Round 3 MEPS Panel 1 sample consisted of 21,411

survey participants.

Panel 2

The 1997 MEPS Panel 2 sample initially consisted

of 6,300 eligible NHIS dwelling units serving as a

nationally representative subsample of the households

responding to NHIS. Like Panel 1, the Panel 2 sample

reflects the oversampling of Hispanic and black

households in NHIS. However, the sample allocation

for Panel 2 of MEPS differed from that for Panel 1

because of the additional oversampling of targeted

policy-relevant groups. The 1996 NHIS response rate

achieved for MEPS-eligible households was 93.8

percent. In Round 1, 6,196 eligible dwelling units were

targeted for interviews, and 5,182 dwelling units

(consisting of 5,536 responding reporting units)

responded, for a rate of .831. The overall MEPS Panel 2

response rate at the end of Round 1 (when data were

collected for the first part of 1997) was 77.9 percent.

This overall rate reflects response to both the 1996

NHIS interview and the MEPS Round 1 interview and

consists of a total sample of 14,505 survey participants.

Combined Response Rates for Point-in-Time

Estimates

Each panel was given equal weight in the

development of sampling weights to produce national

estimates. Therefore, a pooled response rate for the

survey respondents in this data set can be obtained by

taking an average of the panel-specific response rates.

This pooled response rate for the combined panels is

74.1 percent, consisting of a total of 35,916 survey

participants within 14,147 family and single-person

analytical units in MEPS. The weighted MEPS
Figure 1. Overlapping panel design of the Medical Expenditure Panel Survey

for point-in-time estimates

Source: Center for Cost and Financing Studies, Agency for Healthcare Research and Quality.

13

population estimate for the civilian noninstitutionalized

population as of March 1997 was 265,926,692, based on

poststratification to population estimates produced from

the March 1997 Current Population Survey. The

weighted estimate of the number of family units (family

and single-person units) as of March 1997 was

112,106,153, based on data from the same source. 

Using data from the 1997 MEPS Panel 1 Round

3/Panel 2 Round 1 public use file (MEPS HC-005,

<www.meps.ahrq.gov/data.htm#target29>), estimates of

the proportion of the population that was uninsured were

produced for the overall population and for a

representative set of analytical domains, which included

several of the population subgroups targeted for

oversampling (shown in Table 7). The low-income and

high-expenditure population subgroups were not

included in this analysis because 1997 MEPS full-year

data were not available at the time this report was

prepared. Table 7 includes sample yields for the full

1997 MEPS sample, in addition to the level of precision

achieved for the survey estimates as measured by the

relative standard error and the respective survey design

effects.

The 1997 MEPS point-in-time sample includes an

oversample of minorities, with 7,960 Hispanic sample

participants and 5,301 black non-Hispanic sample

participants, which reflects the oversampling rates for

minorities inherent in the NHIS sample (Hispanics,

2.0:1; blacks, 1.5:1). Alternatively, the overall sample

yield for the elderly, consisting of 4,104 sample

participants and 11.4 percent of the sample, is quite

consistent with their proportional representation in the

population, as anticipated by the MEPS sample selection

rates applied to the eligible NHIS sample. As can be

observed in Table 7, the sample yields achieved for the

pooled 1997 MEPS point-in-time sample were consistent

with targeted sample yields for the full-year 1997 MEPS

after adjusting for survey nonresponse. After factoring in

the anticipated sample size reductions attributable to

survey attrition for the point-in-time 1997 estimates of

the uninsured, it is evident that precision levels for the

full-year 1997 MEPS were largely realized when

considering comparable population estimates. It should

be noted that some of the estimates of the uninsured

obtained from the 1997 MEPS were less than 20 percent

(the value used to set precision targets). This partially

explains some of the observed differentials from the

precision targets, which were also specified as average

relative standard errors. 

More specifically, there were 638 adults in the

MEPS sample who, because of an impairment or a

physical or mental problem, received help or supervision

with the ADLs of bathing, dressing, or getting around

the house (Table 7). This subset of ADLs is less inclusive

than the set of ADLs considered in NHIS for

oversampling purposes and indicates the lower bound in

Round 1

Jan Jan

1996 1997

Round 2 Round 3

Round 1

Panel 1

1996-1997

Panel 2

1997-1998
14

terms of sample size yields for this target population. In

addition, a design effect of 1.8 was achieved for the

survey estimate of the uninsured for this policy-relevant

population subgroup. There were also 1,131 adults in the

MEPS sample who, because of an impairment or a

physical or mental problem, received help or supervision

with IADLs, which were using the telephone, paying

bills, taking medications, preparing light meals, doing

laundry, and going shopping (Table 7). This sample yield

is convergent with sample size targets for this policyrelevant population subgroup. A survey design effect of

1.8 was achieved for the associated survey estimate. 

An examination of the efficacy of the sample design

in achieving design goals for children with physical

limitations, households with low incomes, and

individuals with high levels of medical expenditures is

planned. The results will inform future oversampling

efforts in MEPS for these target population subgroups. A

Table 7. 1997 Medical Expenditure Panel Survey sample yields

Pooled (Panels 1 and 2)

1996 1997

unweighted unweighted Unweighted Percent SE Relative SE Design

Demographic subgroup sample sample sample uninsured (percent) (percent) effect

Overall population 21,411 14,505 35,916 16.76 0.389 2.321 3.89

Sex

Male 10,191 6,842 17,033 18.51 0.472 2.550 2.52

Female 11,220 7,663 18,883 15.09 0.414 2.744 2.53

Race/ethnicity

Hispanic 4,610 3,350 7,960 32.94 1.118 3.394 4.51

Black non-Hispanic 2,879 2,422 5,301 21.45 0.985 4.592 3.05

Other 13,922 8,733 22,655 13.63 0.392 2.876 2.95

Age in years

Under 6 1,989 1,450 3,439 14.27 0.895 6.272 2.25

6-17 4,265 3,160 7,425 15.72 0.679 4.319 2.58

18-44 8,296 5,428 13,724 23.36 0.579 2.479 2.57

45-64 4,392 2,832 7,224 14.84 0.587 3.956 1.97

65 and over 2,469 1,635 4,104 1.02 0.194 19.020 1.53

Activity limitations

1 or more ADL (18 years

and over) 292 346 638 4.81 4.137 23.638 1.80

1 or more IADL (18 years 

and over) 528 603 1,131 5.97 0.937 15.695 1.77

Region 

Northeast 4,238 2,752 6,990 14.20 0.639 4.500 2.34

Midwest 4,637 2,941 7,578 12.51 0.728 5.819 3.67

South 7,442 5,150 12,592 19.62 0.745 3.797 4.43

West 5,094 3,662 8,759 18.93 0.921 4.865 4.84

Note: SE = standard error.

Source: Center for Cost and Financing Studies, Agency for Healthcare Research and Quality: Medical Expenditure Panel Survey Household

Component, 1997.
15

similar analysis will be conducted to examine the level

of precision realized for survey estimates of health care

utilization and expenditures.

Annual Estimates for 1997

In order to produce annual health care estimates for

calendar year 1997 based on the full MEPS sample, data

need to be pooled across the first two MEPS national

samples. More specifically, full calendar year 1997 data

collected in Rounds 3-5 for the MEPS Panel 1 sample

are pooled with data from the first three rounds of data

collection for the MEPS Panel 2 sample (Figure 2).

Overall, the full 1997 MEPS household sample consists

of approximately 13,000 reporting units that include

32,636 individuals who completed the full series of

MEPS interviews for their entire period of eligibility,

providing the necessary information to produce national

use and expenditure estimates for calendar year 1997. 

Panel 1

Conditioned on response to Rounds 1-3 of MEPS

Panel 1, 19,622 (90.44 percent) of 21,696 key and inscope individuals eligible for data collection in 1997

provided data for their entire period of eligibility. After

factoring in the impact of survey attrition, the overall

Panel 1 MEPS person-level response rate for deriving

annual estimates was 63.5 percent (.702 x .9044). Of

these full-year respondents for calendar year 1997,

19,407 were in scope on December 31, 1997.

Panel 2

Conditioned on response to Round 1 of MEPS

Panel 2, 13,014 (88.87 percent) of 14,644 key and inscope individuals eligible for data collection in 1997

provided data for their entire period of eligibility. After

factoring in the impact of survey attrition, the overall

Panel 2 MEPS person-level response rate for deriving

annual estimates was 69.2 percent (.779 x .8887). Of

these full-year respondents for calendar year 1997,

12,819 were in scope on December 31, 1997.

Combined Response Rates for Full-Year Estimates 

Each panel was given equal weight in the

development of sampling weights to produce annual

national estimates. Therefore, a pooled response rate for

the survey respondents in this data set can be obtained

by taking an average of the panel-specific response rates.

This pooled response rate for the combined panels is

66.4 percent, and it consists of a total of 32,636 survey

participants. The weighted MEPS population estimate

for the civilian noninstitutionalized population as of

December 31, 1997, was 267,704,802, based on

poststratification to population estimates produced from

the December 1997 Current Population Survey. Sample

yields for the subset of the 32,636 survey participants

who were in scope as of December 31, 1997 (32,226),

controlling for sex, race/ethnicity, region, MSA status,

and age, are presented in Table 8.

Summary

This report has provided a summary of the sample

design features of the 1997 Household Component of

the Medical Expenditure Panel Survey. Particular

attention has been given to the sample selection scheme

implemented for the new 1997 MEPS sample panel. The

report also provides a summary of the precision

specifications for the survey, sample yields, and the level

of precision in survey estimates. The details of the

probabilistic models that were used to select an expected

oversample of low-income households and households

with individuals likely to incur high levels of medical

expenditures in 1997 were also presented, in addition to

measures of the predictive capacity of the respective

models. Both the panel-specific and pooled survey

response rates were summarized for the 1997 MEPS

Panel 1 Round 3/Panel 2 Round 1 point-in-time sample

(first half of 1997) and for annual estimates. 

The MEPS data serve as the primary source of

information for research efforts examining how health

care use and expenditures vary among different sectors

of the population (such as the elderly, veterans, children,

disabled persons, minorities, the poor, and the uninsured)

and how health insurance coverage varies by

demographic characteristics, employment status and

characteristics, geographic locale, and other factors. The

MEPS data are providing and will continue to provide

answers to questions about private health insurance costs

and coverage. These data are helpful in evaluating the

growing impact of managed care on health care

expenditures and enrollment in different types of

managed care plans.
Figure 2. Overlapping panel design of the Medical Expenditure Panel Survey

for full-year estimates

Source: Center for Cost and Financing Studies, Agency for Healthcare Research and Quality.

Round 1

16

Jan Jan Dec Jan

1996 1997 1998

Round 2

Round 1 Round 2

Panel 1

1996-1997

Panel 2

1997-1998 Round 3

Round 3 Round 4 Round 5
17

Table 8. 1997 Medical Expenditure Panel Survey (MEPS) sample yields for full-year

respondents as of December 31, 1997—Panels 1 and 2 combined

Demographic subgroup Unweighted MEPS count Weighted Current Population Survey count

Sex

Male 15,239 130,734,620

Female 16,987 136,970,181

Race/ethnicity

Hispanic 7,440 30,680,491

Black non-Hispanic 4,743 33,578,472

Other 20,043 203,445,838

Region

Northeast 6,144 51,118,238

Midwest 6,763 62,426,339

South 11,309 93,820,483

West 8,010 60,339,742

Metropolitan statistical area (MSA)

MSA 25,119 215,387,710

Non-MSA 7,107 52,317,091

Age in years

Under 1 479 3,819,437

1-4 2,028 15,840,700

5-9 2,854 20,404,149

10-14 2,807 19,563,172

15-19 2,532 19,452,449

20-24 1,913 17,531,979

25-29 1,998 18,827,116

30-34 2,335 20,322,814

35-44 4,963 44,120,234

45-54 3,963 33,907,056

55-59 1,419 11,896,295

60-64 1,198 9,956,233

65-69 1,046 9,413,817

70-74 1,017 8,532,698

75-79 776 6,842,152

80 and over 898 7,274,502

Under 1 479 3,819,437

1-19 10,221 75,260,469

20-29 3,911 36,359,095

30-44 7,298 64,443,048

45-64 6,580 55,759,584

65 and over 3,737 32,063,169

Total 32,226 267,704,802

Note: The MEPS sample size yields presented here represent the population as of December 31, 1997. When the full-year MEPS sample of

all persons with positive person weights is included, the total MEPS respondent sample is 32,636.

Source: Center for Cost and Financing Studies, Agency for Healthcare Research and Quality: Medical Expenditure Panel Survey Household

Component, 1997.
18

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