MEPS HC-037: 1999 Medical Conditions
October 2002
Agency for Healthcare Research and Quality
Center for Cost and Financing Studies
2101 East Jefferson Street, Suite 501
Rockville, MD 20852
(301) 594-1406
TABLE OF CONTENTS
A. Data Use Agreement
B. Background
1.0 Household Component (HC)
2.0 Medical Provider Component (MPC)
3.0 Insurance Component (IC)
4.0 Survey Management
C. Technical Information
1.0 General Information
2.0 Data File Information
2.1 Codebook Structure
2.2 Reserved Codes
2.3 Codebook Format
2.4 Variable Naming
2.5 File Contents
2.5.1 Identifier Variables (DUID-CONDRN)
2.5.2 Medical Condition Variables (PRIOLIST-CCCODEX)
2.5.3 Utilization Variables (OBNUM – RXNUM)
3.0 Sample Weights and Variance Estimation Variables (PERWT99F-VARPSU98)
3.1 Overview
3.2 Details on Person Weights Construction
3.2.1 MEPS Panel 3 Weight
3.2.2 MEPS Panel 4 Weight
3.2.3 The Final Weight for 1999
3.3 Coverage
3.4 Variance Estimation
4.0 Merging MEPS Data Files
References
Appendix 1: Variable to Source Crosswalk
Appendix 2: Condition, Procedure and Clinical Classification Code Frequencies
Appendix 3: Clinical Classification Code to ICD-9 Code Crosswalk
Appendix 4: List of Priority Conditions
A. Data Use Agreement
Individual identifiers have been removed from the micro-data
contained in the files on this CD-ROM. Nevertheless, under sections 308 (d) and
903 (c) of the Public Health Service Act (42 U.S.C. 242m and 42 U.S.C. 299 a-1),
data collected by the Agency for Healthcare Research and Quality (AHRQ) and/or
the National Center for Health Statistics (NCHS) may not be used for any purpose
other than for the purpose for which they were supplied; any effort to determine
the identity of any reported cases is prohibited by law.
Therefore in accordance with the above referenced Federal
Statute, it is understood that:
| 1. |
No one is to use the data in this data set in any way except for
statistical reporting and analysis; and |
| 2. |
If the identity of any person or establishment should be discovered
inadvertently, then (a) no use will be made of this knowledge, (b) the
Director Office of Management AHRQ will be advised of this incident, (c)
the information that would identify any individual or establishment will
be safeguarded or destroyed, as requested by AHRQ, and (d) no one else
will be informed of the discovered identity; and |
| 3. |
No one will attempt to link this data set with individually identifiable
records from any data sets other than the Medical Expenditure Panel Survey
or the National Health Interview Survey. |
By using these data you signify your agreement to comply with
the above stated statutorily based requirements with the knowledge that
deliberately making a false statement in any matter within the jurisdiction of
any department or agency of the Federal Government violates 18 U.S.C. 1001 and
is punishable by a fine of up to $10,000 or up to 5 years in prison.
The Agency for Healthcare Research and Quality requests that
users cite AHRQ and the Medical Expenditure Panel Survey as the data source in
any publications or research based upon these data.
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B. Background
The Medical Expenditure Panel Survey (MEPS) provides
nationally representative estimates of health care use, expenditures, sources of
payment, and insurance coverage for the U.S. civilian non-institutionalized
population. MEPS is cosponsored by the Agency for Healthcare Research and
Quality (AHRQ) and the National Center for Health Statistics (NCHS).
MEPS is a family of three surveys. The Household Component
(HC) is the core survey and forms the basis for the Medical Provider Component (MPC)
and part of the Insurance Component (IC). 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, also known as NMES-1) was
conducted in 1977 and the National Medical Expenditure Survey (NMES-2) in 1987.
Since 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 advance these goals, MEPS includes linkage with the
National Health Interview Survey (NHIS) - a survey conducted by NCHS 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.
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1.0 Household Component (HC)
The MEPS HC, a nationally representative survey of the U.S.
civilian non-institutionalized 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 2 ½-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. NHIS provides a nationally representative sample of the U.S. civilian
non-institutionalized population, with oversampling of Hispanics and blacks.
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2.0 Medical Provider Component (MPC)
The MEPS MPC supplements and/or replaces 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 home
health agencies and pharmacies reported by HC respondents. Office-based
physicians, hospitals, and hospital physicians are also included in the MPC but
may be subsampled at various rates, depending on burden and resources, in
certain years.
Data are collected on medical and financial characteristics
of medical and pharmacy events reported by HC respondents. The MPC is conducted
through telephone interviews and record abstraction.
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3.0 Insurance Component (IC)
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, eligibility
requirements, 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 Bureau of the Census.
|
To provide an integrated picture of health insurance, data
collected from the first sampling frame (employers and insurance providers
identified by MEPS HC respondents) are linked back to data provided by those
respondents. Data from the two Census Bureau sampling frames are used to produce
annual national and State estimates of the supply and cost of private health
insurance available to American workers and to evaluate policy issues pertaining
to health insurance. National estimates of employer contributions to group
insurance from the MEPS IC are 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 follow-up for nonrespondents.
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4.0 Survey Management
MEPS data are collected under the authority of the Public
Health Service Act. They are edited and 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, microdata files and compendiums of tables. Data are released through
MEPSnet, an online interactive tool developed to give users the ability to
statistically analyze MEPS data in real time. Summary reports and compendiums of
tables are released as printed documents and electronic files. Microdata files
are released on CD-ROM and/or electronic files.
Selected printed documents and public use file data on
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.
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.
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C. Technical Information
1.0 General Information
This documentation describes the data contained in MEPS Public Use Release HC-037, which is one in a series of public use data files to be released from 1999 of the Medical Expenditure Panel Survey Household Component (MEPS HC).
Released in ASCII and SAS formats, this public use file provides information on household-reported medical conditions collected on a nationally representative sample of the civilian noninstitutionalized population of the United States for calendar year 1999 MEPS HC.
This file contains 69,897 records. Each record represents one household-reported medical condition reported in the 1999 portion of Round 3, and Rounds 4 and 5 for Panel 3, as well as Rounds 1 and 2 of Panel 4, and the 1999 portion of Round 3 for Panel 4 (i.e., Rounds for MEPS panels covering calendar year 1999).
The following documentation offers a brief overview of the types and levels of data provided, the content and structure of the files and the codebook, and some programming information. It contains the following sections:
Data File Information
Survey Sample Information
Merging MEPS Data Files
Appendices
Variable to Source Crosswalk
Detailed ICD-9 Condition, Procedure, and Clinical Classification Code
Frequencies
List of Priority Conditions
A codebook of all the variables included in the 1999 Medical Conditions File is provided in a separate file (H37CB.PDF). The Readme file contains the programming information.
For more information on MEPS survey design see Cohen, 1997; Cohen 1997; and Cohen 1996. A copy of the survey instrument used to collect this information on this file is available on the MEPS web site: http://www.meps.ahrq.gov.
A
database of all MEPS products released to date and a variable locator indicating
the major MEPS HC data items on public use files that have been released to date
can be found at the following link on the MEPS website: http://www.meps.ahrq.gov/.
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2.0 Data File Information
This file contains 69,897 records. Each record represents one household-reported medical condition reported in the 1999 portion of Round 3, and Rounds 4 and 5 for Panel 3, as well as Rounds 1 and 2 of Panel 4, and the 1999 portion of Round 3 for Panel 4 (i.e., Rounds for MEPS panels covering calendar year 1999). Records included on this file met criterion 1 below and one of criteria 2 - 6.
1. |
The condition is reported by a household survey respondent residing in an eligible responding household. |
2. |
The condition is reported during Rounds 4 and 5 of Panel 3 or Rounds 1 and 2 of Panels 3; or |
3. |
The condition was identified as a priority condition in Panel 3 Rounds 1 or 2 (limited data are available on this file for these records, see Section 2.5.2 for details); or |
4. |
The condition is reported in Round 3 of Panel 3 and links to a 1999 medical provider visit or a medication prescribed in 1999; or |
5. |
The condition is reported in Round 3 or Panel 4 and links to a 1999 medical provider visit or a medicine prescribed in 1999; or |
6. |
The condition is reported in Round 3 for either Panel 3 or Panel 4, does not link to a 1999 medical provider visit or a medication prescribed in 1999, and 50 percent or more of a respondent’s reference period occurred in 1999. |
For each variable on the file, both weighted and unweighted frequencies are provided in the codebook. Because the conditions identified in this file are derived from self-reports, these data cannot be used to make estimates of disease, prevalence of health conditions, or mortality/morbidity.
Data from this file can be merged with 1999 MEPS person-level data using DUPERSID to append person-level characteristics such as demographic or health insurance characteristics to each record (see Section 4.0 for details). Data from this file also can be merged to 1999 MEPS Medical Provider Event Files (HC-033A, HC-033B, HC-033D through HC-033H) by using the link files provided on HC-033I, File 1 (see HC-033I for details). Since each record represents a single condition reported by household respondents, some household respondents may have multiple medical conditions and thus will be represented on multiple records on this file. Other household respondents may have reported no medical conditions and thus will have no records on this file.
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2.1 Codebook Structure
The codebook and data file sequence lists variables in the following order:
- Unique person identifiers
|
- Unique condition identifiers
|
- Medical condition variables
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- Weight and variance estimation variables
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2.2 Reserved Codes
The following reserved code values are used:
| VALUE DEFINITION |
|
| -1 INAPPLICABLE |
Question was not asked due to skip
pattern |
| -7 REFUSED |
Question was asked and respondent refused to answer question. |
| -8 DK |
Question was asked and
respondent did not know answer |
| -9 NOT ASCERTAINED |
Interviewer did not record the data |
Generally, -1, -7, -8, and -9 have not been edited on this file. The values of -1 and -9 can be edited by analysts by following the skip patterns in the questionnaire. These reserve codes indicated appropriate responses for skip patterns associated with priority and injury conditions (see HC-018 Sections 2.2 for details.) Priority and injury conditions on the current file did not undergo the extensive editing they did on previous releases of the Medical Conditions file. Data users should note that the reserve codes -11 and -12 are not used on the current file.
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2.3 Codebook Format
This codebook describes an ASCII data set and provides the
following programming identifiers for each variable:
| IDENTIFIER |
DESCRIPTION |
| Name |
Variable name (maximum of 8 characters) |
| Description |
Variable descriptor (maximum 40 characters) |
| Format |
Number of bytes |
| Type |
Type of data: numeric (indicated by NUM) or character (indicated by CHAR) |
| Start |
Beginning column position of variable in record |
| End |
Ending column position of variable in record |
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2.4 Variable Naming
In general, variable names reflect the content of the variable, with an 8-character limitation. For questions asked in a specific Round, the end digit in the variable name reflects the Round in which the question was asked. Edited variables end in an "X" and are so noted in the variable label.
Variables contained in this delivery were derived either from the questionnaire itself or from the CAPI. The source of each variable is identified in Appendix 1 entitled "Variable to Source Crosswalk." Sources for each variable are indicated in one of four ways: (1) variables which are derived from CAPI or assigned in sampling are so indicated; (2) variables derived from complex algorithms associated with re-enumeration are labeled "RE Section"; (3) variables which come from one or more specific questions have those numbers and questionnaire section indicated in the "Source" column; (4) variables constructed from multiple questions using complex algorithms are labeled "Constructed" in the "SOURCE" column.
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2.5 File Contents
2.5.1 Identifier Variables (DUID-CONDRN)
The definitions of Dwelling Units (DU s) and Group Quarters in the MEPS-HC are generally consistent with the definitions employed for the National Health Interview Survey (NHIS). The dwelling unit ID (DUID) is a five-digit random number assigned after the case was sampled for MEPS. The person number (PID) uniquely identifies each person within the dwelling unit. The variable DUPERSID uniquely identifies each person represented on the file, and is the combination of the variables DUID and PID. CONDN indicates the condition number as it was reported during the interview for an individual respondent (e.g., condition number 1, 2, 3, etc.) plus a control digit. The current range for CONDN is 10-386 (1-38 conditions per person). Because some records did not meet the criteria to be included on the file (see Section 2.0) the actual number of records per person represented on the file is 1-31 and CONDN has not been edited. CONDIDX uniquely identifies each condition (i.e., each record on the file), and is the combination of DUPERSID and CONDN.
PANEL99 is a constructed variable used to specify the panel number for the interview. PANEL99 will indicate either Panel 3 or Panel 4.
CONDRN indicates the round in which the condition was first reported. For a small number of cases, conditions that actually began in an earlier round were not reported by respondents until subsequent rounds of data collection. For these cases no editing was performed to reconcile the round in which a condition began and the round that the condition was first reported.
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2.5.2 Medical Condition Variables
(PRIOLIST-CCCODEX)
This file contains variables describing medical conditions reported by respondents in several sections of the MEPS questionnaire, including the Condition Enumeration Section, Health Status Section, and all questionnaire sections collecting information about health provider visits, prescription medications, and disability days (see Variable-Source Crosswalk in Appendix 1 for details).
Priority Conditions and Injuries
Certain conditions were a priori designated as "priority conditions" (PRIOLIST=1) due to their prevalence, expense, or relevance to policy. Some were long-term life-threatening conditions, such as cancer, diabetes, emphysema, high cholesterol, HIV/AIDS, hypertension, ischemic heart disease, and stroke. Others were chronic manageable conditions, including arthritis, asthma, gall bladder disease, stomach ulcers, and back problems of any kind. In addition, Alzheimer’s disease or other dementias, as well as depression and anxiety disorders, were included in the priority list. For a complete listing of "priority conditions" see Appendix 4. Priority conditions were identified as such in the field by MEPS interviewers. Occasionally errors were made and not all priority conditions were identified. Consequently, these records are missing the follow-up questions described below. Likewise, some conditions were inaccurately identified as priority conditions. These records do have follow-up questions even though they are not priority conditions.
When a condition was first mentioned, respondents were asked whether it was due to an accident or an injury (INJURY=1). Some injuries are also priority conditions (e.g. back pain).
Date Priority Condition Began/Accident Occurred
The date a priority condition began (CONDBEGD, CONDBEGM, CONDBEGY) is collected only for conditions that appear on the priority list. The date an accident or injury occurred (ACCDENTD, ACCDENTM, ACCDENTY) is collected only for accident/injury conditions.
Round Specific Questions for Priority Conditions and Injuries
When a respondent first reported a condition on the priority list (PRIOLIST=1) or a condition caused by an injury (INJURY=1), a series of questions regarding health care utilization for that condition and the effect of that condition on the person’s overall health was asked. The names of these variables end in 1, 2, 3, 4 or 5 indicating the round in which they were asked. The following questions were asked in the round in which the respondent first reported a priority condition or a condition resulting from an injury.
a. |
Whether the respondent ever saw or talked to a doctor about the condition (SEEDREV1 – SEEDREV5). |
b. |
Whether the latest time a doctor was seen for this condition was before or after the beginning of the reference period for the interview Round (LSTSAW1). This question was asked only in Round 1. |
c. |
Whether the person was still being treated for the condition (STILTR1-STILTR5). |
d. |
How seriously the condition affected the person’s overall health and well-being since it began (OVRALL1-OVRALL5). |
e. |
Whether the person with the condition himself/herself provided the information, versus being reported by another household member (WHOTYP1 – WHOTYP5). |
f. |
Whether the health care provider recommended further treatment or consultation for the condition (FURTCA1 – FURTCA5). |
g. |
How much follow-up care the person received for the condition (all; some; none; or still being treated) (FOLOCA1 – FOLOCA5). |
h. |
Whether the person saw or talked to a doctor about the condition during the reference period (SEEDREF1 – SEEDREF5). This variable was constructed for priority conditions only. |
When a respondent reported a condition that resulted from an accident or injury (INJURY=1) the following information was obtained from respondents during the round in which the injury was first reported.
| a. |
whether or not the accident/injury occurred at work (ACCDNWRK) – respondents aged 16 and younger were not asked this question and coded ACCDNWRK = 1; |
| b. |
where the accident happened (ACDNTLOC); |
| c. |
if the accident/injury occurred at home, was it inside or outside the house. (INOUTHH); |
| d. |
whether or not the accident involved another vehicle, gun, weapon other than a gun, poison, fire, drowning or near-drowning, sports injury, a fall, something else (VEHICLE, GUN, WEAPON, POISON, FIREBURN, DROWN, SPORTS, FALL, ACDNTOTH); |
| e. |
whether or not the person has fully recovered from the injury (RECOVER); |
For priority conditions only, additional information was obtained in rounds subsequent to the one in which the condition was first mentioned. This information was obtained only if there was a medical provider visit or a prescribed medication or a disability day associated with the condition in that round. If this occurred, the condition was "selected" for follow-up questions for the round.
For priority conditions selected in rounds after they were first mentioned, the following questions were asked:
| a. |
Whether the person saw or talked to a doctor about the condition during the reference period (SEEDREF1 – SEEDREF5). |
| b. |
Whether the person was still being treated for the condition (STILTR1 – STILTR5). |
| c. |
How seriously the condition affected the person’s overall health and well-being since it began (OVRALL1 – OVRALL5). |
| d. |
Whether the person with the condition himself/herself provided the information, versus being reported by another household member (WHOTYP1 – WHOTYP5). |
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Treatment of Data from Rounds Not Occurring in 1999
For Panel 3, Rounds 1 and 2 occurred in 1997 and are not included on this file unless the condition was identified as a priority condition (see the discussion of PRIOFLG below). For Panel 4, Rounds 4 and 5 occurred in 2000 and are not included on this file. Therefore, round-specific variables for Rounds 1 and 2 of Panel 3 are assigned an inapplicable code (-1) for respondents in Panel 3, and round-specific variables for Rounds 4 and 5 of Panel 4 are assigned an inapplicable code (-1). Data for Rounds 4 and 5 pertain only to Panel 3; data for Rounds 1 and 2 pertain only to Panel 4, and both panels provide data from Round 3. (Note: PANEL99 must be used to identify whether Round 3 variables were collected in Panel 3 or Panel 4.)
All priority conditions and conditions resulting from an injury that were first reported in Rounds 1 or 2 of Panel 3 have round-specific data for those rounds included on the 1998 Medical Conditions File (HC-027). The variables PRIOFLG and INJURFLG indicate if the condition is "Not a priority/injury condition" (0), whether or not "Additional information is included on the 1998 Medical Condition File" (1), or if "all priority/injury information is included on the current file" (2).
Note: Priority conditions are generally chronic conditions. Even though a respondent may not have reported a medical provider visit, a prescribed medicine or a disability in 1999 due to the condition, analysts should consider that the respondent is probably still experiencing the condition. If a Panel 3 respondent reported a priority condition in Rounds 1 or 2 and did not have a provider visit, a prescribed medicine, or a disability day for the condition in Rounds 3, 4 or 5 of Panel 3, round-specific variables for Rounds 3, 4, and 5 are coded as –1. The only information provided on the current 1999 file is the ICD9CODX, ICD9PROX, and CCCODEX. These records also can be identified if PRIOFLG=1.
Rounds in Which Conditions were Reported/Selected (CRND1 – CRND5)
A set of constructed variables (CRND1 – CRND5) indicate the round in which the condition was first reported, and for subsequent rounds, the round(s) in which a medical provider event, prescription medication, or disability day occurred due to condition. For example, consider a condition for which CRND1 = 0, CRND2 = 1, and CRND3 = 1; this sequence of CRND indicators implies that the condition was not present during Round 1 (CRND1 = 0), was first mentioned during Round 2, and was associated with a medical event during Round 3. These round indicators have not been reconciled with CONDRN. CRND1 – CRND5 are not applicable for most pregnancies, prenatal visits, or deliveries due to the questionnaire design.
This file contains 3 flag variables indicating whether or not a condition is associated with a missed workday (MISSWORK), a missed school day (MISSSCHL), or a bed day (INBEDFLG). Due to the MEPS instrument design, there is no link indicating the number of disability days associated with a particular medical condition.
Diagnosis and Procedure Codes
The medical conditions and procedures reported by the Household Component respondent were recorded by the interviewer as verbatim text, which were then coded to fully-specified 1999 ICD-9-CM codes, including medical condition and V codes (see Health Care Financing Administration, 1980), by professional coders. Although codes were verified and error rates did not exceed 2.5 percent for any coder, analysts should not presume this level of precision in the data; the ability of household respondents to report condition data that can be coded accurately should not be assumed (see Cox and Iachan, 1987; Edwards, et al, 1994; and Johnson and Sanchez, 1993).
In order to preserve respondent confidentiality, nearly all of the condition codes provided on this file (ICD9CODX) have been collapsed from fully specified codes to 3-digit code categories. Table 1 in Appendix 2 provides a table of unweighted and weighted frequencies for all ICD-9 condition code values reported on the file. In this table, values that reflect this collapsing have an asterisk in the label indicating that the 3-digit category includes all the subclassifications within that category. For example, the ICD9CODX value of 034 "Strep Throat/Scarlet Fev *" includes the fully-specified subclassifications 034.0 and 034.1; the value 296 "Affective Disorders*" includes the fully specified subclassifications 296.0 through 296.99. Less than 1 percent of the records on this file were edited further by collapsing two or more 3-digit codes into one 3-digit code.
Similarly, most of the procedure codes (ICD9PROX) were collapsed from fully specified codes to 2-digit category codes. Table 2 in Appendix 2 provides unweighted and weighted frequencies for ICD9PROX, and this type of collapsing is identified by an asterisk in the variable label. For example, the ICD9PROX value in 81 "Joint Repair*" includes subclassifications 81.0 through 81.99. Some records were further edited to combine 2 or more 2-digit categories.
Users should note that because of the design of the survey, most deliveries (i.e. births) are coded as pregnancies. For more accurate estimates for deliveries analysts should use RSINHOS "Reason Entered Hospital" found on the Hospital Inpatient Stays Public Use File (HC-033D).
Conditions and procedures were reported in the same sections of the HC questionnaire (see Variable-Source Crosswalk in Appendix 1). Labels for all values of the variables ICD9CODX and ICD9PROX, as shown in Tables 1 and 2, are provided in the SAS programming statements included in this release (see the HC-035SU.TXT file).
Clinical Classification Codes
ICD-9-CM condition codes have been aggregated
into clinically meaningful categories that group similar conditions
(CCCODEX). CCODEX was generated using Clinical Classification Software
(formerly known as Clinical Classifications for Health Care Policy
Research (CCHPR)), (Elixhauser, et al., 1999), which aggregates conditions
and V-codes into 259 mutually exclusive categories, most of which
are clinically homogeneous. Appendix 3 lists the ICD-9-CM codes that
have been aggregated for each clinical classification category. Note
that the reported ICD-9-CM code values were mapped to the appropriate
clinical classification category prior to being collapsed to 3-digit
ICD-9 codes. For confidentiality purposes a small number (less than
2 percent) of clinical classification codes have been edited. Table
3 in Appendix 2 provides weighted and unweighted frequencies for
CCCODEX. Labels for all values of the variable CCCODEX, as shown
in Table 3, are provided in the SAS programming statements included
in this release (see the HC-035SU.TXT file).
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2.5.3 Utilization Variables
(OBNUM – RXNUM)
The variables are OBNUM, OPNUM, HHNUM, DNNUM, HSNUM, ERNUM, and RXNUM indicate the total number of 1999 medical provider events that can be linked to each condition record on the current file for each event type, i.e., office-based, outpatient, home health, dental, hospital stays, emergency room visits, and prescribed medicines, respectively.
These counts of events were derived from Medical Provider Event Public Use Files (HC-033A, HC-033B and HC-033D - HC-033H). Medical provider events associated with conditions include all utilization that occurred between January 1, 1999 and December 31, 1999.
Because persons can be seen for more than one condition per visit, these frequencies will not match the person- or event-level utilization counts. For example, if a person had one hospital stay and was treated for a fractured hip and a fractured shoulder and a concussion, each of these conditions has a unique record and HSNUM=1 for each record. If you sum HSNUM for these records, then the total hospital stays would be 3 when actually there was only 1 hospital stay for that person and 3 conditions were treated. These variables are useful if you wanted to know the number of hospitals for head injuries, hip fractures, etc.
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3.0 Sample Weights and Variance Estimation Variables (PERWT99F-VARPSU98)
3.1 Overview
There is a single full year person-level weight (PERWT99F) assigned to each record for each key, in-scope person who responded to MEPS for the full period of time that he or she was in-scope during 1999. A key person either was a member of an NHIS household at the time of the NHIS interview, or became a member of such a household after being out-of-scope at the time of the NHIS (examples of the latter situation include newborns and persons returning from military service, an institution, or living outside the United States). A person is in-scope whenever he or she is a member of the civilian noninstitutionalized portion of the U.S. population.
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3.2 Details on Person Weights Construction
The person-level weight PERWT99F was developed in three stages. A person level weight for Panel 4 was created, including both an adjustment for nonresponse over time and poststratification, controlling to Current Population Survey (CPS) population estimates based on five variables. Variables used in the establishment of person-level poststratification control figures included: census region (Northeast, Midwest, South, West); MSA status (MSA, non-MSA); race/ethnicity (Hispanic, black but non-Hispanic, and other); sex; and age. Then a person level weight for Panel 3 was created, again including an adjustment for nonresponse over time and poststratification, again controlling to CPS population estimates based on the same five variables. When poverty status information derived from income variables became available, a 1999 composite weight was formed from the Panel 3 and Panel 4 weights by multiplying the Panel weights by .5. Then a final poststratification was done on this composite weight variable, including poverty status (below poverty, from 100 to 125 percent of poverty, from 125 to 200 percent of poverty, from 200 to 400 percent of poverty, at least 400 percent of poverty) as well as the original five poststratification variables in the establishment of control totals.
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3.2.1 MEPS Panel 3 Weight
The person level weight for MEPS Panel 3 was developed using the 1998 full year weight for an individual as a "base" weight for survey participants present in 1998. For key, in-scope respondents who joined a RU some time in 1999 after being out of scope in 1998, the 1998 family weight associated with the family the person joined served as a "base" weight. The weighting process included an adjustment for nonresponse over Rounds 4 and 5 as well as poststratification to population control figures for December 1999. These control figures were derived by scaling back the population totals obtained from the March 1999 CPS to reflect the December, 1999 CPS estimated population distribution across age and sex categories as of December, 1999. Variables used in the establishment of person level poststratification control figures included: census region (Northeast, Midwest, South, West); MSA status (MSA, non-MSA); race/ethnicity (Hispanic, black but non-Hispanic, and other); sex, and age. Overall, the weighted population estimate for the civilian, noninstitutionalized population on December 31, 1999 is 273,003,778. Key, responding persons not in-scope on December 31, 1999 but in-scope earlier in the year retained, as their final Panel 3 weight, the weight after the nonresponse adjustment.
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3.2.2 MEPS Panel 4 Weight
The person level weight for MEPS Panel 4 was developed using the MEPS Round 1 person-level weight as a ‘base" weight. For key, in-scope respondents who joined a RU after Round 1, the Round 1 family weight served as a "base" weight. The weighting process included an adjustment for nonresponse over Round 2 and the 1999 portion of Round 3 as well as poststratification to the same population control figures for December 1999 used for the MEPS Panel 3 weights. The same five variables employed for Panel 3 poststratification (census region, MSA status, race/ethnicity, sex, and age) were used for Panel 4 poststratification. Similarly, for Panel 4, key, responding persons not in-scope on December 31, 1999 but in-scope earlier in the year retained, as their final Panel 4 weight, the weight after the nonresponse adjustment.
Note that the MEPS round 1 weights (for both panels with one exception as noted below) incorporated the following components: the original household probability of selection for the NHIS; ratio-adjustment to NHIS-based national population estimates at the household (occupied dwelling unit) level; adjustment for nonresponse at the dwelling unit level for Round 1; and poststratification to figures at the family and person level obtained from the March 1999 CPS data base.
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3.2.3 The Final Weight for 1999
Variables used in the establishment of person level poststratification control figures included: poverty status (below poverty, from 100 to 125 percent of poverty, from 125 to 200 percent of poverty, from 200 to 400 percent of poverty, at least 400 percent of poverty); census region (Northeast, Midwest, South, West); MSA status (MSA, non-MSA); race/ethnicity (Hispanic, black but non-Hispanic, and other); sex, and age. Overall, the weighted population estimate for the civilian, noninstitutionalized population for December 31, 1999 is 273,003,778 (PERWT99F>0 and INSC1231=1). The inclusion of key, in-scope persons who were not in-scope on December 31, 1999 brings the estimated total number of persons represented by the MEPS respondents over the course of the year up to 276,410,767 (PERWT99F>0). The weighting process included poststratification to population totals obtained from the 1996 MEPS Nursing Home Component for the number of individuals admitted to nursing homes. For the 1999 full year file an additional poststratification was done to population totals obtained from the 1998 Medicare Current Beneficiary Survey (MCBS) for the number of deaths among Medicare beneficiaries experienced in the 1999 MEPS.
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3.3 Coverage
The target population for MEPS in this file is the 1999 U.S. civilian, noninstitutionalized population. However, the MEPS sampled households are a subsample of the NHIS households interviewed in 1998 (Panel 3) and 1999 (Panel 4). New households created after the NHIS interviews for the respective Panels and consisting exclusively of persons who entered the target population after 1998 (Panel 3) or after 1999 (Panel 4) are not covered by MEPS. These would include families consisting solely of: immigrants; persons leaving the military; U.S. citizens returning from residence in another country; and persons leaving institutions. It should be noted that this set of uncovered persons constitutes only a tiny proportion of the MEPS target population
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3.4 Variance Estimation
To obtain estimates of variability (such as the standard error of sample estimates or corresponding confidence intervals) for estimates based on MEPS survey data, one needs to take into account the complex sample design of MEPS. Various approaches can be used to develop such estimates of variance including use of the Taylor series or various replication methodologies. Replicate weights have not been developed for the MEPS 1999 data. Variables needed to implement a Taylor series estimation approach are provided in the file and are described in the paragraph below.
Using a Taylor Series approach, variance estimation strata and the variance estimation PSUs within these strata must be specified. The corresponding variables on the MEPS full year utilization database are VARSTR99 and VARPSU99, respectively. Specifying a "with replacement" design in a computer software package such as SUDAAN (Shah, 1996) should provide standard errors appropriate for assessing the variability of MEPS survey estimates. It should be noted that the number of degrees of freedom associated with estimates of variability indicated by such a package may not appropriately reflect the actual number available. For MEPS sample estimates for characteristics generally distributed throughout the country (and thus the sample PSUs), there are over 100 degrees of freedom associated with the corresponding estimates of variance.
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4.0 Merging MEPS Data Files
Data from the current file can be used alone or in conjunction with other files. Merging characteristics of interest from person-level files expands the scope of potential estimates. See HC-033I for instructions on merging the condition file to the Medical Event Files. Person-level characteristics can be merged to the condition file using the following procedure:
| 1. |
Sort the person-level file by person identifier, DUPERSID. Keep only variables to be merged on to the conditions file and DUPERSID. |
| 2. |
Sort the conditions file by person identifier, DUPERSID. |
| 3. |
Merge both files by DUPERSID, and output all records in the conditions file. |
| 4. |
If PERS contains the person-level variables, and COND is the conditions file, the following code can be used to add person-level variables to the person’s conditions in condition-level file. |
PROC SORT DATA=PERS(KEEP=DUPERSID AGE SEX EDUC)
OUT=PERSX; BY DUPERSID;
RUN;
PROC SORT DATA=COND; BY DUPERSID;
RUN;
DATA COND;
MERGE COND (IN=A) PERSX(IN=B); BY DUPERSID;
IF A;
RUN;
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References
Cohen, S. B. (1997). A Sample Design of the 1996 Medical Expenditure Panel Survey Household Component, Rockville (MD): Agency for Healthcare Research and Quality; 1997. MEPS Methodology Report, No. 2. AHCPR Pub. No. 97-0027.
Cohen, J. W. (1997). A Design and Methods of the Medical Expenditure Panel Survey Household Component. Rockville (MD): Agency for Healthcare Research and Quality; 1997. MEPS Methodology Report, No.1. AHCPR Pub. No. 97-0026.
Cohen, S. B. (1996). The Redesign of the Medical Expenditure Panel Survey: A Component of the DHHS Survey Integration Plan. Proceedings of the COPAFS Seminar on Statistical Methodology in the Public Service.
Cohen, S. B. (2000) 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
Cox, B. and Iachan, R. (1987). A Comparison of Household and Provider Reports of Medical Conditions. Journal of the American Statistical Association 82(400):1013-18.
Edwards, W. S., Winn, D. M., Kurlantzick, V., et al. Evaluation of National Health Interview Survey Diagnostic Reporting. National Center for Health Statistics, Vital Health 2(120). 1994.
Elixhauser, A., Steiner, C. A., Whittington, C. A., and McCarthy, E. Clinical Classifications for health policy research: Hospital inpatient statistics, 1995. Healthcare Cost and Utilization project, HCUP-3 research Note. Rockville, MD: Agency for Healthcare Research and Quality; 1999. AHCPR Pub. No. 98-0049.
Health Care Financing Administration (1980). International Classification of Diseases, 9th Revision, Clinical Modification (ICD-CM). Vol. 1. (DHHS Pub. No (PHS) 80-1260). DHHS: U.S. Public Health Services.
Johnson, Ayah E., and Sanchez, Maria Elena. (1993), "Household and Medical Reports on Medical Conditions: National Medical Expenditure Survey." Journal of Economic and Social Measurement, 19, 199-223.
Shah, B. V., B. G. Barnwell, G. S. Bieler, K. E. Boyle, R. E. Folsom, L. Lavange, S. C. Wheeless, and R. Williams (1996). Technical Manual: Statistical Methods and Algorithms Used in SUDAAN Release 7.0, Research Triangle Park, NC: Research Triangle Institute.
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Appendix 1: VARIABLE TO SOURCE CROSSWALK
FOR MEPS PUBLIC USE RELEASE HC-037
UNIQUE IDENTIFIER VARIABLES
VARIABLE |
LABEL |
SOURCE[1] |
DUID |
Dwelling Unit ID (DU) |
Assigned in Sampling |
PID |
Person Number (PN) |
Assigned in Sampling |
DUPERSID |
Sample person ID (DU + PN) |
Assigned in Sampling |
CONDN |
Condition Number |
CAPI Derived |
CONDIDX |
Cond ID Key: DUID + Counter (3) + CONDN |
CAPI Derived |
PANEL99 |
Panel Number |
Constructed |
CONDRN |
Condition Round Number |
CAPI Derived |
[1]
See the README file in the Survey Instruments section of the MEPS home page, for
informationon the MEPS HC questionnaire sections (e.g., RE, CN) shown in the
Source column.
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MEDICAL CONDITION VARIABLES
VARIABLE |
LABEL |
SOURCE |
PRIOLIST |
Is Condition On Priority List |
CN02 |
CONDBEGD |
Date Condition Started --Day |
CN05 |
CONDBEGM |
Date Condition Started BMonth |
CN05 |
CONDBEGY |
Date Condition Started --Year |
CN05 |
SEEDREV1 |
RD1: Ever See/Talk to Dr. About Condition |
CN03, CN07 |
SEEDREV2 |
RD2: Ever See/Talk to Dr. About Condition |
CN03, CN07 |
SEEDREV3 |
RD3: Ever See/Talk to Dr. About Condition |
CN03, CN07 |
SEEDREV4 |
RD4: Ever See/Talk to Dr. About Condition |
CN03, CN07 |
SEEDREV5 |
RD5: Ever See/Talk to Dr. About Condition |
CN03, CN07 |
LSTSAW1 |
RD1: When Was Last Time Dr. Was Seen |
CN04 (Edited) |
STILTR1 |
RD1: Is Person Still Treated For Condition |
CN11, CN18 (Edited) |
STILTR2 |
RD2: Is Person Still Treated For Condition |
CN11, CN18 (Edited) |
STILTR3 |
RD3: Is Person Still Treated For Condition |
CN11, CN18 (Edited) |
STILTR4 |
RD4: Is Person Still Treated For Condition |
CN11, CN18 (Edited) |
STILTR5 |
RD5: Is Person Still Treated For Condition |
CN11, CN18 (Edited) |
OVRALL1 |
RD1: How Did Condition Affect Overall Health |
CN13, CN19 (Edited) |
OVRALL2 |
RD2: How Did Condition Affect Overall Health |
CN13, CN19 (Edited) |
OVRALL3 |
RD3: How Did Condition Affect Overall Health |
CN13, CN19 (Edited) |
OVRALL4 |
RD4: How Did Condition Affect Overall Health |
CN13, CN19 (Edited) |
OVRALL5 |
RD5: How Did Condition Affect Overall Health |
CN13, CN19 (Edited) |
WHOTYP1 |
RD1: Who Reported Condition Affect |
CN13OV, CN19OV (Edited) |
WHOTYP2 |
RD2: Who Reported Condition Affect |
CN13OV, CN19OV (Edited) |
WHOTYP3 |
RD3: Who Reported Condition Affect |
CN13OV, CN19OV (Edited) |
WHOTYP4 |
RD4: Who Reported Condition Affect |
CN13OV, CN19OV (Edited) |
WHOTYP5 |
RD5: Who Reported Condition Affect |
CN13OV, CN19OV (Edited) |
FURTCA1 |
RD1: Was Further Treatment Recommended |
CN14 (Edited) |
FURTCA2 |
RD2: Was Further Treatment Recommended |
CN14 (Edited) |
FURTCA3 |
RD3: Was Further Treatment Recommended |
CN14 (Edited) |
FURTCA4 |
RD4: Was Further Treatment Recommended |
CN14 (Edited) |
FURTCA5 |
RD5: Was Further Treatment Recommended |
CN14 (Edited) |
FOLOCA1 |
RD1: Receive Follow-Up Care for Condition |
CN15 (Edited) |
FOLOCA2 |
RD2: Receive Follow-Up Care for Condition |
CN15 (Edited) |
FOLOCA3 |
RD3: Receive Follow-Up Care for Condition |
CN15 (Edited) |
FOLOCA4 |
RD4:Receive Follow-Up Care for Condition |
CN15 (Edited) |
FOLOCA5 |
RD5:Receive Follow-Up Care for Condition |
CN15 (Edited) |
SEEDREF1 |
RD1: Saw Doctor in Reference Period |
CN17 |
SEEDREF2 |
RD2: Saw Doctor in Reference Period |
CN17 |
SEEDREF3 |
RD3: Saw Doctor in Reference Period |
CN17 |
SEEDREF4 |
RD4: Saw Doctor in Reference Period |
CN17 |
SEEDREF5 |
RD5: Saw Doctor in Reference Period |
CN17 |
CRND1 |
RD 1: Has Condition Round Information |
Constructed |
CRND2 |
RD 2: Has Condition Round Information |
Constructed |
CRND3 |
RD 3: Has Condition Round Information |
Constructed |
CRND4 |
RD 4: Has Condition Round Information |
Constructed |
CRND5 |
RD 5: Has Condition Round Information |
Constructed |
PRIORFLG |
1 = Initial Priority Information on 1997 File |
|
INJURY |
Was Condition Due To Accident/Injury |
CN02 |
ACCDENTD |
Date Of Accident -- Day |
CN06 |
ACCDENTM |
Date Of Accident B Month |
CN06 |
ACCDENTY |
Date Of Accident B Year |
CN06 |
ACCDNWRK |
Did Accident Occur At Work |
CN07 |
ACDNTLOC |
Where Did Accident Happen |
CN08 |
INOUTHH |
Was Accident inside/Outside House |
CN09 |
VEHICLE |
Was A Motor Vehicle Involved |
CN10 |
GUN |
Was A Gun Involved |
CN10 |
WEAPON |
Was Some Other Weapon Involved |
CN10 |
POISON |
Was Poison/Poisonous Substance Involved |
CN10 |
FIREBURN |
Was Fire/Burning Involved |
CN10 |
DROWN |
Was Drowning/Near Drowning Involved |
CN10 |
SPORTS |
Was It A Sports Injury |
CN10 |
FALL |
Was It A Fall |
CN10 |
ACDNTOTH |
Was Something Else Involved |
CN10 |
RECOVER |
Fully Recovered From Condition |
CN12 |
INJURFLG |
1 = Initial Injury Information on 1997 File |
|
MISSWORK |
Flag Associated With Missed Work days |
DD04 |
MISSSCHL |
Flag Associated With Missed School Days |
DD08 |
INBEDFLG |
Flag Associated With Bed Days |
DD12 |
ICD9CODX |
ICD-9 Code for Condition |
CE05, HS03, ER04,
OP09, MV09, DN02,
HH05, PM09 (Edited) |
ICD9PROX |
ICD-9 Code for Procedure |
CE05, HS03, ER04,
OP09, MV09, DN02,
HH05, PM09 (Edited) |
CCCODEX |
Clinical Classification Code |
Constructed/Edited |
HHNUM |
# Home Health Events Assoc. w/ Condition |
Constructed |
DNNUM |
# Dental Events Assoc. w/ Condition |
Constructed |
HSNUM |
# Hospital Stays Assoc. w/ Condition |
Constructed |
OPNUM |
# Out-Patient Events Assoc. w/ Condition |
Constructed |
OBNUM |
# Office-Based Events Assoc. w/ Condition |
Constructed |
ERNUM |
# ER Assoc. w/ Condition |
Constructed |
RXNUM |
# Prescribed Medicines Associations W/ Condition |
Constructed |
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WEIGHTS AND VARIANCE ESTIMATION VARIABLES
VARIABLE |
LABEL |
SOURCE |
PERWT99F |
Final Person Level Weight, 1999 |
Constructed |
VARPSU99 |
Variance Estimation PSU 1999 |
Constructed |
VARSTR99 |
Variance Estimation Stratum 1999 |
Constructed |
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Appendix 2: Condition, Procedure and Clinical Classification Code Frequencies (link to separate file)
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Appendix 3: Clinical Classification Code to ICD-9 Code Crosswalk (link to CCS/ICD9CM crosswalk)
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Appendix 4: List of Priority Conditions
LIST OF PRIORITY CONDITIONS
A. LONG-TERM, LIFE THREATENING CONDITIONS:
Cancer (of any body part)
cancer
tumor
malignancy
malignant tumor
carcinoma
sarcoma
lymphoma
Hodgkin’s disease
leukemia
melanoma
metastasis
neuroma
adenoma
Diabetes
diabetes
diabetes mellitus
high blood sugar
juvenile diabetes (Type I diabetes)
adult-onset diabetes (Type II diabetes)
diabetic neuropathy
Emphysema
emphysema
chronic obstructive pulmonary disease
(COPD)
chronic bronchitis (MUST use the word
("chronic", only for adults)
chronic obstructive bronchitis (MUST
use the word "chronic", only for
adults)
smoker’s cough |
High Cholesterol
high cholesterol
high or elevated triglycerides
hyperlipidemia
hypercholesterolemia
HIV/AIDS
HIV
AIDS
Hypertension
hypertension
high blood pressure
Ischemic Heart Disease
ischemic heart disease (MUST use
the word "ischemic")
angina
angina pectoris
coronary artery disease
blocked, obstructed, or occluded
coronary arteries
arteriosclerosis
myocardial infarction
heart attack
Stroke
stroke
cerebral hemorrhage
cerebral aneurysm
transient ischemic accident
transient ischemic attack
apoplexy
carotid artery blockage
arterial thrombosis in brain
blood clot in brain |
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B. CHRONIC, MANAGEABLE CONDITIONS:
Arthritis
anything with the word "arthritis"
rheumatoid arthritis
degenerative arthritis
osteoarthritis
bursitis
rheumatism
Asthma
anything with the word "asthma" or
"asthmatic"
Gall Bladder Disease
gall bladder disease, trouble,
attacks, infection, or problems
gallstones
Stomach Ulcers
stomach ulcer
duodenal ulcer
peptic ulcer
bleeding ulcer
ulcerated stomach
perforated ulcer |
Back Problems of Any Kind
back problems or pain of any kind
(lower or upper back)
sore, hurt, injured, or stiff back
backache
anything with the words "vertebra",
"vertebrae", "lumbar", "spine", or
"spinal"
strained or pulled muscle in back
sprained back
muscle spasms
back spasms
bad back
lumbago
sciatica or sciatic nerve problems
disc problems: herniated, ruptured,
slipped, compressed, extruded,
dislocated, deteriorated, or misaligned
discs |
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C. MENTAL HEALTH ISSUES:
Alzheimer’s Disease and Other Dementias
anything with the words "Alzheimer’s" or "dementia"
organic brain syndrome
Depression and Anxiety Disorders
depression (including severe, chronic, or major depression)
dysthymia
dysthymic disorder
bipolar disorder
manic depression or manic depressive illness
anxiety attacks
panic attacks
anxiety
nerves
nervous condition
nervous breakdown
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