MEPS HC-051E: 2000 Emergency Room Visits
March 2003
Agency for Healthcare Research and Quality
Center for Financing, Access, and Cost Trends
540 Gaither Road
Rockville, MD 20850
(301) 427-1406
Table of Contents
A. Data Use Agreement
B. Background
1.0 Household Component
2.0 Medical Provider Component
3.0 Insurance Component
4.0 Survey Management
C. Technical And Programming 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 Source and Naming Conventions
2.4.1 General
2.4.2 Expenditure and Source of Payment Variables
2.5 File Contents
2.5.1
Survey Administration Variables
2.5.1.1 Person Identifiers (DUID,
PID, DUPERSID)
2.5.1.2 Record Identifiers
(EVNTIDX, ERHEVIDX, FFEEIDX)
2.5.1.3 Round Indicator
(EVENTRN)
2.5.2 MPC Data Indicator (MPCDATA) C-7
2.5.3
Emergency Room Visit Event Variables
2.5.3.1 Visit Details
(ERDATEYR-VSTRELCN)
2.5.3.2 Services, Procedures, and
Prescription Medicines (LABTEST-MEDPRESC)
2.5.4 VA Facility (VAPLACE)
2.5.5 Condition and Procedure Codes
(ERICD1X-ERICD3X, ERPRO1X), and Clinical Classification Codes
(ERCCC1X-RCCC3X)
2.5.6 Flat Fee Variables (FFEEIDX,
FFERTYPE, FFBEF00,
FFTOT01)
2.5.6.1 Definition of Flat Fee Payments
2.5.6.2 Flat Fee Variable Descriptions
2.5.6.2.1 Flat Fee ID
(FFEEIDX)
2.5.6.2.2 Flat Fee Type
(FFERTYPE)
2.5.6.2.3 Counts of Flat Fee Events
that Cross Years (FFBEF00, FFTOT01)
2.5.6.3 Caveats of Flat Fee Groups
2.5.7 Expenditure Data
2.5.7.1 Definition of Expenditures
2.5.7.2 Data Editing and Imputation
Methodologies of Expenditure Variables
2.5.7.2.1 General Data Editing
Methodology
2.5.7.2.2 General Hot-Deck Imputation
2.5.7.2.3 Emergency Room Visit Data
Editing and Imputation
2.5.7.3 Imputation Flag
(IMPFLAG)
2.5.7.4 Flat Fee Expenditures
2.5.7.5 Zero Expenditures
2.5.7.6 Discount Adjustment Factor
2.5.7.7 Emergency Room/Hospital Inpatient
Stay Expenditures
2.5.7.8 Sources of Payment
2.5.7.9 Imputed Emergency Room Expenditure
Variables
2.5.7.9.1 Emergency Room Facility
Expenditures (ERFSF00X-ERFOT00X, ERFXP00X, ERFTC00X)
2.5.7.9.2 Emergency Room Physician
Expenditures (ERDSF00X - ERDOT00X, ERDXP00X, ERDTC00X)
2.5.7.9.3 Total Expenditures and
Charges for Emergency Room Visits (ERXP00X, ERTC00X)
2.5.8 Rounding
3.0 Sample Weight (PERWT00F)
3.1 Overview
3.2 Details on Person Weight Construction
3.2.1 MEPS Panel 4 Weight
3.2.2 MEPS Panel 5 Weight
3.2.3 The Final Weight for 2000
3.2.4 Coverage
4.0 Strategies for Estimation
4.1 Variables with Missing Values
4.2 Basic Estimates of Utilization, Expenditures
and Sources of Payment
4.3 Estimates of the Number of Persons with
Emergency Room Visit Events
4.4 Person-Based Ratio Estimates
4.4.1 Person-Based Ratio Estimates Relative to
Persons with Emergency Room Use
4.4.2 Person-Based Ratio Estimates Relative to the Entire
Population
4.5 Sampling Weights for Merging Previous Releases
of MEPS Household Data with this Event File
4.6 Variance Estimation (VARSTR00, VARPSU00)
5.0 Merging/Linking MEPS Data Files
5.1 Merging a 2000 Person-Level File to the 2000
Emergency Room Visit File
5.2 Linking the 2000 Emergency Room Visits File to
the 2000 Medical Conditions File and/or the 2000 Prescribed Medicines
File
5.2.1 Limitations/Caveats of RXLK (the Prescribed Medicine
Link File)
5.2.2 Limitations/Caveats of CLNK (the Medical Conditions
Link File)
References
D. Variable-Source Crosswalk
A. Data Use Agreement
Individual identifiers have been removed from the
microdata contained in the files in this release. 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:
- No one is to use the data in this data set in any
way except for statistical reporting and analysis.
- 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.
- 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 Title 18
part 1 Chapter 47 Section 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 noninstitutionalized
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) was conducted in
1977, and the National Medical Expenditure Survey (NMES) was conducted in 1987.
Since 1996, MEPS has continued 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
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 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 noninstitutionalized population, with oversampling of Hispanics
and blacks.
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2.0 Medical Provider Component
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
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
identified by MEPS HC respondents) are linked back to data provided by those
respondents. Data collected 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 health 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 also 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 as electronic files.
Selected printed documents 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 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 and
Programming Information
1.0 General Information
This documentation describes one in a series of public use
event files from the 2000 Medical Expenditure Panel Survey (MEPS) Household
Component (HC) and Medical Provider Component (MPC). Released as an ASCII data
file and a SAS transport file, the 2000 Emergency Room Visits (EROM) public use
event file provides detailed information on emergency room visits for a
nationally representative sample of the civilian noninstitutionalized population
of the United States. Data from the EROM event file can be used to make
estimates of emergency room utilization and expenditures for calendar year 2000.
As illustrated below, this file consists of MEPS survey data from the 2000
portion of Round 3, and Rounds 4 and 5 for Panel 4, as well as Rounds 1, 2, and
the 2000 portion of Round 3 for Panel 5 (i.e., the rounds for the MEPS panels
covering calendar year 2000).
Medical Expenditure Panel Survey Calendar
1999 through 2000
301 Moved Permanently
301 Moved Permanently
Emergency room events reported in Round 3 Panel 5 and
known to have occurred after December 31, 2000 are not included on this file. In
addition to expenditures, each record contains household reported medical
conditions and procedures associated with the emergency room visit.
Counts of emergency room visits are based entirely on
household reports. Information from the MEPS MPC was used to supplement
expenditure and payment data reported by the household.
Data from the emergency room event file can be merged with
other 2000 MEPS HC data files for purposes of appending person-level data such
as demographic characteristics or health insurance coverage to each emergency
room record.
This file can also be used to construct summary variables
of expenditures, sources of payment, and related aspects of emergency room
visits. Aggregate annual person-level information on the use of emergency rooms
and other health services use is provided on the MEPS 2000 Full Year
Consolidated Data File, where each record represents a MEPS sampled person.
This documentation offers an overview of the types and
levels of data provided, and the content and structure of the file and the
codebook. It contains the following sections:
Data File Information
Sample Weights
Strategies for Estimation
Merging/Linking MEPS Data Files
References
Variable - Source Crosswalk
Any variables not found on this file but released on
previous years' files were excluded because they contained only missing data.
For more information on MEPS HC survey design see S.
Cohen, 1997; J. Cohen, 1997; and S. Cohen, 1996. For information on the MEPS MPC
design, see S. Cohen, 1998. Copies of the HC and the MPC survey
instruments used to collect the information on the EROM file are available in
the Survey Instrument section of the MEPS web site at the following
address: <http://www.meps.ahrq.gov>.
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2.0 Data File Information
The 2000 emergency room visits public use data set
consists of one event-level data file. The file contains characteristics
associated with the EROM event and imputed expenditure data. For users wanting
to impute expenditures, pre-imputed data are available through the CCFS data
center. Please visit the CCFS data center web site for details: <http://www.meps.ahrq.gov/data_stats/onsite_datacenter.jsp>.
The data user/analyst is forewarned that the imputation of expenditures will
necessitate a sizable commitment of resources: financial, staff, and time.
The 2000 EROM public use data set contains variables and
frequency distributions for 4,192 emergency room visits reported during the 2000
portion of Round 3 and Rounds 4 and 5 for Panel 4, as well as Rounds 1, 2, and
the 2000 portion of Round 3 for Panel 5 of the MEPS Household Component. The
file includes emergency room visit records for all household survey respondents
who resided in eligible responding households and reported at least one
emergency room visit. Records where the emergency room visit was known to have
occurred after December 31, 2000 are not included on this file. Of these 4,192 records, 4,014 were associated with persons having
positive person-level weights (PERWT00F). The persons represented on this file
had to meet either (a) or (b):
- Be classified as a key in-scope person who
responded for his or her entire period of 2000 eligibility (i.e.,
persons with a positive 2000 full-year person-level weight (PERWT00F
> 0)), or
- Be an eligible member of a family all of
whose key in-scope members have a positive person-level weight
(PERWT00F > 0). (Such a family consists of all persons with the
same value for FAMIDYR.) That is, the person must have a positive
full-year family-level weight (FAMWT00F >0). Note that FAMIDYR and
FAMWT00F are variables on the 2000 Population Characteristics file.
Persons with no emergency room visits for 2000 are not
included on this file but are represented on the 2000 MEPS person-level files. A
codebook for the data file is provided in files H51ECB.PDF and H51ECB.ASP.
Each emergency room visit record includes the following:
date of the visit; whether or not person saw doctor; type of care received; type
of services (i.e., lab test, sonogram or ultrasound, x-rays, etc.) received;
medicines prescribed during the visit; flat fee information; imputed sources of
payment; total payment and total charge; and a full-year person-level weight.
Data from this file can be merged with the MEPS 2000 Full
Year Population Characteristics File using the unique person identifier,
DUPERSID, to append person-level information, such as demographic or health
insurance characteristics, to each record. Emergency room visit events can also
be linked to the MEPS 2000 Medical Conditions File and the MEPS 2000 Prescribed
Medicines File. Please see Section 5.2 and the 2000 Appendix File, HC-051I for
details on how to merge MEPS data files.
Panel 4 cases (PANEL00 = 4 on the 2000 Full Year
Population Characteristics File) can also be linked back to the 1999 MEPS HC
public use data files. However, data users/analysts should be aware that, at
this time, no weight is being provided to facilitate two-year analysis of Panel
4 data.
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2.1 Codebook Structure
For each variable on the Emergency Room Events event file,
both weighted and unweighted frequencies are provided in the codebook
(H51ECB.PDF and
H51ECB.ASP). The codebook and data file sequence list
variables in the following order:
Unique person identifiers
Unique emergency room event identifiers
Emergency room characteristic variables
ICD-9 condition and procedure codes
Clinical Classification Software (CCS) codes
Imputed expenditure variables
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, values of -1, -7, -8, and -9 for
non-expenditure variables have not been edited on this file. The values of -1
and -9 can be edited by the data users/analysts by following the skip patterns
in the HC survey questionnaire (located on the MEPS web site: <http://www.meps.ahrq.gov/survey_comp/survey.jsp>).
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2.3 Codebook Format
The EROM codebook describes an ASCII data set (although
the data are also being provided in a SAS transport file). The following
codebook items are provided for each variable:
Identifier |
Description |
Name |
Variable name (maximum of 8 characters) |
Description |
Variable descriptor (maximum of 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 Source and Naming Conventions
In general, variable names reflect the content of the
variable, with an eight-character limitation. All imputed/edited variables end
with an "X."
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2.4.1 General
Variables on this file were derived from the HC
questionnaire itself, derived from the MPC data collection instrument, derived
from CAPI, or assigned in sampling. The source of each variable is identified in
Section D "Variable - Source Crosswalk" in one of four ways:
- Variables derived from CAPI or assigned in sampling
are indicated as "CAPI derived" or "Assigned in
sampling," respectively;
- Variables which come from one or more specific
questions have those questionnaire sections and question numbers indicated
in the "Source" column; questionnaire sections are identified
as:
- ER - Emergency Room Section
- FF - Flat Fee Section
- CP - Charge Payment Section;
- Variables constructed from multiple questions using
complex algorithms are labeled "Constructed" in the
"Source" column; and
- Variables which have been edited or imputed are so
indicated.
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2.4.2 Expenditure and Source
of Payment Variables
The names of the expenditure and source of payment
variables follow a standard convention, are eight characters in length, and end
in an "X" indicating edited/imputed. Please note that imputed means
that a series of logical edits, as well as an imputation process to account for
missing data, have been performed on the variable.
The total sum of payments and the 12 source of payment
variables are named in the following way:
The first two characters indicate the type of event:
IP - inpatient stay |
OB - office-based visit |
ER - emergency room visit |
OP - outpatient visit |
HH - home health visit |
DV - dental visit |
OM - other medical equipment |
RX - prescribed medicine |
For expenditure variables on these files, the third
character indicates whether the expenditure is associated with the facility (F)
or the physician (D).
In the case of the source of payment variables, the fourth
and fifth characters indicate:
SF - self or family |
OF - other Federal Government |
MR - Medicare |
SL - State/local government |
MD - Medicaid |
WC - Workers' Compensation |
PV - private insurance |
OT - other insurance |
VA - Veterans Administration |
OR - other private |
TR - TRICARE |
OU - other public |
|
XP - sum of payments |
In addition, the total charge variable is indicated by TC
in the variable name.
The sixth and seventh characters indicate the year (00).
The eighth character of all imputed/edited variables is an "X."
For example, ERFSF00X is the edited/imputed amount paid by
self or family for the facility portion of the expenditure associated with an
emergency room visit.
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2.5 File Contents
2.5.1 Survey Administration
Variables
2.5.1.1 Person Identifiers (DUID,
PID, DUPERSID)
The dwelling unit ID (DUID) is a five-digit random number
assigned after the case was sampled for MEPS. The three-digit person number (PID)
uniquely identifies each person within the dwelling unit. The eight-character
variable DUPERSID uniquely identifies each person represented on the file and is
the combination of the variables DUID and PID. For detailed information on
dwelling units and families, please refer to the documentation for the 2000 Full
Year Population Characteristics File.
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2.5.1.2
Record Identifiers (EVNTIDX, ERHEVIDX, FFEEIDX)
EVNTIDX uniquely identifies each emergency room
visit/event (i.e., each record on the emergency room visit file) and is the
variable required to link emergency room events to data files containing details
on conditions and/or prescribed medicines (MEPS 2000 Medical Conditions File and
the MEPS 2000 Prescribed Medicines File, respectively). For details on linking,
see Section 5.2 or the MEPS 2000 Appendix File, HC-051I.
ERHEVIDX is a constructed variable identifying an EROM
record that has its facility expenditures represented on an associated hospital
inpatient stay record. This variable was constructed by comparing date
information for the reported hospital stay and all emergency room visits for the
same person. On the 2000 EROM file, there are 284 emergency room events linked
to subsequent hospital stays. Please note that where the emergency room visit is
associated with a hospital stay (and its expenditures and charges are included
with the hospital stay), the physician expenditures associated with the
emergency room visit remain on the emergency room file.
FFEEIDX is a constructed variable which uniquely
identifies a flat fee group, that is, all events that were a part of a flat fee
payment situation.
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2.5.1.3 Round Indicator (EVENTRN)
EVENTRN indicates the round in which the emergency room
visit was reported. Please note: Rounds 3, 4, and 5 are associated with MEPS
survey data collected from Panel 4. Likewise, Round 1, 2, and 3 are associated
with data collected from Panel 5.
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2.5.2 MPC Data Indicator (MPCDATA)
MPCDATA is a constructed variable which indicates whether
or not MPC data were collected for the emergency room visit. While all emergency
room events are sampled into the Medical Provider Component, not all emergency
room event records have MPC data associated with them. This is dependent upon
the cooperation of the household respondent to provide permission forms to
contact the emergency room facility as well as the cooperation of the emergency
room facility to participate in the survey.
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2.5.3 Emergency Room Visit
Event Variables
This file contains variables describing emergency room
visits/events reported by household respondents in the Emergency Room section of
the MEPS HC questionnaire. The questionnaire contains specific probes for
determining details about the emergency room event. These variables have not
been edited.
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2.5.3.1
Visit Details (ERDATEYR-VSTRELCN)
When a person reported having had a visit to the emergency
room, the date of the emergency room visit was recorded (ERDATEYR, ERDATEMM,
ERDATEDD). Also reported is whether or not the person saw a medical doctor (SEEDOC).
The type of care the person received (VSTCTGRY) and whether or not the visit was
related to a specific condition (VSTRELCN) were also determined.
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2.5.3.2 Services,
Procedures, and
Prescription Medicines (LABTEST-
MEDPRESC)
Services received during the visit included whether or not
the person received lab tests (LABTEST), a sonogram or ultrasound (SONOGRAM),
x-rays (XRAYS), a mammogram (MAMMOG), an MRI or CAT scan (MRI), an
electrocardiogram (EKG), an electroencephalogram (EEG), a vaccination (RCVVAC),
anesthesia (ANESTH), or other diagnostic tests or exams (OTHSVCE). Whether or
not a surgical procedure was performed during the visit was asked (SURGPROC)
and, if so, the procedure name (SURGNAME) was also asked. The questionnaire
determined if a medicine was prescribed for the person during the emergency room
visit (MEDPRESC). See Section 5.2 for information on linking to the prescription
medicine events file.
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2.5.4 VA Facility (VAPLACE)
VAPLACE is a constructed variable that indicates whether
the provider worked at a VA facility. This variable only has valid data for
providers that were sampled into the Medical Provider Component. All other
providers are classified as "No".
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2.5.5 Condition and
Procedure Codes (ERICD1X-ERICD3X, ERPRO1X), and Clinical Classification
Codes (ERCCC1X-ERCCC3X)
Information on household reported medical conditions and
procedures associated with each emergency room visit are provided on this file.
There are up to three condition and CCS codes (ERICD1X-ERICD3X, ERCCC1X-ERCCC3X)
and one procedure code (ERPRO1X) listed for each emergency room visit. In order
to obtain complete condition information associated with an event, the data
user/analyst must link to the MEPS 2000 Medical Conditions File. Details on how
to link the 2000 EROM event file to the MEPS 2000 Medical Conditions File are
provided in Section 5.2.2 and the MEPS 2000 Appendix File, HC-051I. The
data user/analyst should note that because of confidentiality restrictions,
provider-reported condition information is not publicly available.
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 2000 ICD-9-CM codes, including
medical conditions and V codes (Health Care Financing Administration, 1980) by
professional coders. Although codes were verified and error rates did not exceed
3 percent for any coder, data users/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 (Cox and Cohen, 1985;
Cox and Iachan, 1987; Edwards, et al, 1994; and Johnson and Sanchez, 1993). For
detailed information on how conditions and procedures were coded, please refer
to the documentation on the MEPS 2000 Medical Conditions File. For frequencies
of conditions by event type, please see the MEPS 2000 Appendix File, HC-051I.
The ICD-9-CM condition codes were aggregated into
clinically meaningful categories. These categories, included on the file as
ERCCC1X-ERCCC3X, were generated using Clinical Classification Software [formerly
known as Clinical Classifications for Health Care Policy Research (CCHPR)], (Elixhauser,
et al., 1998), which aggregates conditions and V-codes into 260 mutually
exclusive categories, most of which are clinically homogeneous.
In order to preserve respondent confidentiality, nearly
all of the condition codes provided on this file have been collapsed from
fully-specified codes to three-digit code categories. The reported ICD-9-CM code
values were mapped to the appropriate clinical classification category prior to
being collapsed to the three-digit categories. Details on this procedure are
outlined in the 2000 Medical Conditions File.
The condition codes (and clinical classification codes)
and procedure codes linked to each emergency room visit are sequenced in the
order in which the conditions were reported by the household respondent, which
was in order of input into the database and not in order of importance or
severity. Data users/analysts who use the MEPS 2000 Medical Conditions File in
conjunction with this emergency room visits file should note that the order of
conditions on this file is not identical to that on the Medical Conditions file.
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2.5.6
Flat Fee Variables (FFEEIDX, FFERTYPE, FFBEF00, FFTOT01)
2.5.6.1
Definition of Flat Fee Payments
A flat fee is the fixed dollar amount a person is charged
for a package of health care services provided during a defined period of time.
Examples would be: obstetrician's fee covering a normal delivery, as well as
pre- and post-natal care; or a surgeon's fee covering surgical procedure and
post-surgical care. A flat fee group is the set of medical services (i.e.,
events) that are covered under the same flat fee payment situation. The flat fee
groups represented on this file include flat fee groups where at least one of
the health care events, as reported by the HC respondent, occurred during 2000.
By definition, a flat fee group can span multiple years. Furthermore, a single
person can have multiple flat fee groups.
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2.5.6.2 Flat Fee Variable Descriptions
2.5.6.2.1 Flat Fee ID
(FFEEIDX)
As noted earlier in Section 2.5.1.2 "Record
Identifiers," the variable FFEEIDX uniquely identifies all events that are
part of the same flat fee group for a person. On any 2000 MEPS event file, every
event that is part of a specific flat fee group will have the same value for
FFEEIDX. Note that prescribed medicine and home health events are never included
in a flat fee group and FFEEIDX is not a variable on those event files.
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2.5.6.2.2 Flat Fee Type
(FFERTYPE)
FFERTYPE indicates whether the 2000 emergency room visit
is the "stem" or "leaf" of a flat fee group. A stem (records
with FFERTYPE = 1) is the initial medical service (event) which is followed by
other medical events that are covered under the same flat fee payment. The
leaves of the flat fee group (records with FFERTYPE = 2) are those medical
events that are tied back to the initial medical event (the stem) in the flat
fee group. These "leaf" records have their expenditure variables set
to zero. For the emergency room visits that are not part of a flat fee payment
situation, the FFERTYPE is set to -1, "INAPPLICABLE."
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2.5.6.2.3 Counts of Flat
Fee Events that Cross Years (FFBEF00, FFTOT01)
As described in Section 2.5.5.1,
a flat fee payment situation may cover multiple events, and the multiple events
could span multiple years. For situations where the emergency room event
occurred in 2000 as part of a group of events, and some event occurred before or
after 2000, counts of the known events are provided on the emergency room
record. Variables indicating events that occurred before or after 2000 are as
follows:
FFBEF00 - total number of pre-2000 events in the
same flat fee group as the 2000 emergency room visit(s). This count would
not include the 2000 emergency room visit(s).
FFTOT01 - indicates the number of 2001 emergency
room visits, expected to be in the same flat fee group as the emergency room
event that occurred in 2000.
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2.5.6.3 Caveats of Flat Fee Groups
There are 43 emergency room visits that are identified as
being part of a flat fee payment group. In general, every flat fee group should
have an initial visit (stem) and at least one subsequent visit (leaf). There are
some situations where this is not true. For some flat fee groups, the initial
visit reported occurred in 2000, but the remaining visits that were part of this
flat fee group occurred in 2001. In this case, the 2000 flat fee group
represented on this file would consist of one event, the stem. The 2001 events
that are part of this flat fee group are not represented on the file. Similarly,
the household respondent may have reported a flat fee group where the initial
visit began in 1997 but subsequent visits occurred during 2000. In this case,
the initial visit would not be represented on the file. This 2000 flat fee group
would then only consist of one or more leaf records and no stem.
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2.5.7
Expenditure Data
2.5.7.1 Definition of Expenditures
Expenditures on this file refer to what is paid for health
care services. More specifically, expenditures in MEPS are defined as the sum of
payments for care received for each emergency room visit, including
out-of-pocket payments and payments made by private insurance, Medicaid,
Medicare and other sources. The definition of expenditures used in MEPS differs
slightly from its predecessors: the 1987 NMES and 1977 NMCES surveys where
"charges" rather than sum of payments were used to measure
expenditures. This change was adopted because charges became a less appropriate
proxy for medical expenditures during the 1990's due to the increasingly common
practice of discounting. Although measuring expenditures as the sum of payments
incorporates discounts in the MEPS expenditure estimates, the estimates do not
incorporate any payment not directly tied to specific medical care visits, such
as bonuses or retrospective payment adjustments by third party payers. Another
general change from the two prior surveys is that charges associated with
uncollected liability, bad debt, and charitable care (unless provided by a
public clinic or hospital) are not counted as expenditures because there are no
payments associated with those classifications. While charge data are provided
on this file, data users/analysts should use caution when working with this data
because a charge does not typically represent actual dollars exchanged for
services or the resource costs of those services; nor are they directly
comparable to the expenditures defined in the 1987 NMES. For details on
expenditure definitions, please reference "Informing American Health Care
Policy" (Monheit et al., 1999). AHRQ has developed factors to apply to the
1987 NMES expenditure data to facilitate longitudinal analysis. These factors
can be assessed via the CCFS data center. For more information, see the data
center section of the MEPS web site <http://www.meps.ahrq.gov>.
Expenditure data related to emergency room visits are
broken out by facility and separately billing doctor expenditures. This file
contains five categories of expenditure variables per visit: basic hospital
emergency room facility expenses; expenses for doctors who billed separately
from the hospital for any emergency room services provided during the emergency
room visit; total expenses, which is the sum of the facility and physician
expenses; facility total charge; and physician total charge.
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2.5.7.2 Data Editing and Imputation
Methodologies of Expenditure Variables
The expenditure data included on this file were derived
from both the MEPS Household (HC) and Medical Provider Component (MPC). The MPC
contacted medical providers identified by household respondents. The charge and
payment data from medical providers were used in the expenditure imputation
process to supplement missing household data. For all emergency room visits, MPC
data were used if complete; otherwise, HC data were used if complete. Missing
data for emergency room visits, where HC data were not complete and MPC data
were not collected or complete, were imputed through the imputation process.
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2.5.7.2.1 General Data
Editing Methodology
Logical edits were used to resolve internal
inconsistencies and other problems in the HC and MPC survey-reported data. The
edits were designed to preserve partial payment data from households and
providers, and to identify actual and potential sources of payment for each
household-reported event. In general, these edits accounted for outliers,
copayments or charges reported as total payments, and reimbursed amounts that
were reported as out-of-pocket payments. In addition, edits were implemented to
correct for mis-classifications between Medicare and Medicaid and between
Medicare HMOs and private HMOs as payment sources. These edits produced a
complete vector of expenditures for some events, and provided the starting point
for imputing missing expenditures in the remaining events.
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2.5.7.2.2 General Hot-Deck
Imputation
A weighted sequential hot-deck procedure was used to
impute missing expenditures as well as total charge. This procedure uses survey
data from respondents to replace missing data while taking into account the
respondents' weighted distribution in the imputation process. Classification
variables vary by event type in the hot-deck imputations, but total charge and
insurance coverage are key variables in all of the imputations. Separate
imputations were performed for nine categories of medical provider care:
inpatient hospital stays, outpatient hospital department visits, emergency room
visits, visits to physicians, visits to non-physician providers, dental
services, home health care by certified providers, home health care by paid
independents, and other medical expenses. Within each event type file, separate
imputations were performed for flat fee and simple events. After the imputations
were finished, visits to physician and non-physician providers were combined
into a single medical provider file. The two categories of home care also were
combined into a single home health file.
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2.5.7.2.3
Emergency Room Visit Data Editing and Imputation
Facility expenditures for emergency room services were
developed in a sequence of logical edits and imputations. "Household"
edits were applied to sources and amounts of payment for all events reported by
HC respondents. "MPC" edits were applied to provider-reported sources
and amounts of payment for records matched to household-reported events. Both
sets of edits were used to correct obvious errors in the reporting of
expenditures. After the data from each source were edited, a decision was made
as to whether household- or MPC-reported information would be used in the final
editing and hot-deck imputations for missing expenditures. The general rule was
that MPC data would be used where a household-reported event corresponded to an
MPC-reported event (i.e., a matched event), since providers usually have more
complete and accurate data on sources and amounts of payment than households.
One of the more important edits separated flat fee events
from simple events. This edit was necessary because groups of events covered by
a flat fee (i.e., a flat fee bundle) were edited and imputed separately from
individual events covered by a single charge (i.e., simple events). Most
emergency room events were imputed as simple events because hospital facility
charges are rarely bundled with other events. (See Section 2.5.5 for more
details on flat fee groups). However, some emergency room visits were treated as
free events because the respondent was admitted to a hospital through its
emergency room. In these cases, emergency room charges are included in the
charge for an inpatient hospital stay.
Logical edits also were used to sort each event into a
specific category for the imputations. Events with complete expenditures were
flagged as potential donors for the hot-deck imputations, while events with
missing expenditure data were assigned to various recipient categories. Each
event was assigned to a recipient category based on the extent of its missing
charge and expenditure data. For example, an event with a known total charge but
no expenditure information was assigned to one category, while an event with a
known total charge and partial expenditure information was assigned to a
different category. Similarly, events without a known total charge and no or
partial expenditure information were assigned to various recipient categories.
The logical edits produced eight recipient categories in
which all events had a common extent of missing data. Separate hot-deck
imputations were performed on events in each recipient category, and the donor
pool was restricted to events with complete expenditures from the MPC. The donor
pool restriction was used even though some unmatched events had complete
household-reported expenditures. These events were not allowed to donate
information to other events because the MPC data were considered to be more
reliable.
The donor pool included "free events" because,
in some instances, providers are not paid for their services. These events
represent charity care, bad debt, provider failure to bill, and third party
payer restrictions on reimbursement in certain circumstances. If free events
were excluded from the donor pool, total expenditures would be over-counted
because the cost of free care would be implicitly included in paid events and
explicitly included in events that should have been treated as free from
provider.
Expenditures for some emergency room visits are not shown
because the person was admitted to the hospital through the emergency room.
These emergency room events are not free, but the expenditures are included in
the inpatient stay expenditures. The variable ERHEVIDX can be used to
differentiate between free emergency room care and situations where the
emergency room charges have been included in the inpatient hospital charges.
Expenditures for services provided by separately billing
doctors in hospital settings were also edited and imputed. These expenditures
are shown separately from hospital facility charges for hospital inpatient,
outpatient, and emergency room care.
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2.5.7.3 Imputation Flag (IMPFLAG)
Only one imputation flag was created for 2000 event files.
This flag, IMPFLAG, is a six-category variable that indicates if the event
contains complete Household Component (HC) or Medical Provider Component (MPC)
data, was fully or partially imputed, or was imputed in the capitated imputation
process (for OP and MV events only). The following list identifies how the
imputation flag is coded; the categories are mutually exclusive.
IMPFLAG=0 not eligible for imputation (includes zeroed
out and leaf events)
IMPFLAG=1 complete HC data
IMPFLAG=2 complete MPC data
IMPFLAG=3 fully imputed
IMPFLAG=4 partially imputed
IMPFLAG=5 complete MPC data through capitation
imputation (not applicable to ER events)
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2.5.7.4 Flat Fee Expenditures
The approach used to count expenditures for flat fees was
to place the expenditure on the first visit of the flat fee group. The remaining
visits have zero payments. Thus, if the first visit in the flat fee group
occurred prior to 2000, all of the events that occurred in 2000 will have zero
payments. Conversely, if the first event in the flat fee group occurred at the
end of 2000, the total expenditure for the entire flat fee group will be on that
event, regardless of the number of events it covered after 2000. See Section
2.5.3 for details on the flat fee variables.
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2.5.7.5 Zero Expenditures
There are some medical events reported by respondents
where the payments were zero. This could occur for several reasons including (1)
free care was provided, (2) bad debt was incurred, (3) care was covered under a
flat fee arrangement beginning in an earlier year, (4) follow-up visits were
provided without a separate charge (e.g., after a surgical procedure), or (5)
emergency room visit expenditures were included on the linked hospital record.
If all of the medical events for a person fell into one of these categories,
then the total annual expenditures for that person would be zero.
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2.5.7.6 Discount Adjustment Factor
An adjustment was also applied to some HC-reported
expenditure data because an evaluation of matched HC/MPC data showed that
respondents who reported that charges and payments were equal were often unaware
that insurance payments for the care had been based on a discounted charge. To
compensate for this systematic reporting error, a weighted sequential hot-deck
imputation procedure was implemented to determine an adjustment factor for
HC-reported insurance payments when charges and payments were reported to be
equal. As for the other imputations, selected predictor variables were used to
form groups of donor and recipient events for the imputation process.
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2.5.7.7 Emergency Room/Hospital
Inpatient Stay Expenditures
It is common for an emergency room visit to result in a
hospital stay. However, while it is true that all of the event files can be
linked by DUPERSID, there is no unique record link between hospital inpatient
stays and emergency room visits. However, wherever this relationship could be
identified (using MPC start and end dates of the events as well as other
information from the provider), the facility expenditure associated with the
emergency room visit was moved to the hospital facility expenditure. Hence, the
expenditures (and charges) for some emergency room visits are included in the
resulting hospitalization. In these situations, the emergency room record on
this file will have its expenditure (and charge) information zeroed out to avoid
double-counting while its corresponding hospital inpatient stay record on the
MEPS 2000 Hospital Inpatient Stays File will have the combined expenditures.
Please note that any physician expenditures associated with emergency room
events remain on the emergency room event file. The variable ERHEVIDX identifies
the emergency room visits whose expenditures are included in the expenditures
for the following hospital inpatient stay. It should also be noted that for
these cases there is only one emergency room stay associated with the hospital
room stay.
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2.5.7.8 Sources of Payment
In addition to total expenditures, variables are provided
which itemize expenditures according to major source of payment categories.
These categories are:
- Out-of-pocket by user or family,
- Medicare,
- Medicaid,
- Private Insurance,
- Veterans Administration, excluding TRICARE,
- TRICARE, formerly CHAMPUS/CHAMPVA,
- Other Federal sources - includes Indian Health
Service, Military Treatment Facilities, and other care by the Federal
government,
- Other State and Local Source - includes community
and neighborhood clinics, State and local health departments, and State
programs other than Medicaid,
- Workers' Compensation, and
- Other Unclassified Sources - includes sources such
as automobile, homeowner's, liability, and other miscellaneous or
unknown sources.
Two additional source of payment variables were created to
classify payments for events with apparent inconsistencies between health
insurance coverage and sources of payment based on data collected in the survey.
These variables include:
- Other Private - any type of private insurance
payments reported for persons not reported to have any private health
insurance coverage during the year as defined in MEPS, and
- Other Public - Medicare/Medicaid payments
reported for persons who were not reported to be enrolled in the
Medicare/Medicaid program at any time during the year.
Though relatively small in magnitude, data users/analysts
should exercise caution when interpreting the expenditures associated with these
two additional sources of payment. While these payments stem from apparent
inconsistent responses to health insurance and source of payment questions in
the survey, some of these inconsistencies may have logical explanations. For
example, private insurance coverage in MEPS is defined as having a major medical
plan covering hospital and physician services. If a MEPS sampled person did not
have such coverage but had a single service type insurance plan (e.g., dental
insurance) that paid for a particular episode of care, those payments may be
classified as "other private." Some of the "other public"
payments may stem from confusion between Medicaid and other state and local
programs or may be from persons who were not enrolled in Medicaid, but were
presumed eligible by a provider who ultimately received payments from the
program.
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2.5.7.9 Imputed Emergency Room
Expenditure Variables
This file contains two sets of imputed expenditure
variables: facility expenditures and physician expenditures.
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2.5.7.9.1 Emergency Room
Facility Expenditures (ERFSF00X-ERFOT00X, ERFXP00X, ERFTC00X)
Emergency room expenses include all expenses for
treatment, services, tests, diagnostic and laboratory work, x-rays, and similar
charges, as well as any physician services included in the emergency room
charge.
If the physician charges were included in the emergency
room visit bill, then this expenditure is included in the facility expenditure
variables. The imputed facility expenditures provided on this file (ERFSF00X -
ERFOT00X) are the 12 sources of payment: self/family, Medicare, Medicaid,
private insurance, Veterans Administration, TRICARE, other federal, state/local
governments, Workers' Compensation, other private insurance, other public
insurance and other insurance. ERFXP00X is the sum of the 12 sources of payments
for the facility expenditure and ERFTC00X is the total charge. Please note that
where an emergency room visit record is linked to a hospital inpatient stay
record, ERFTC00X has been zeroed out.
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2.5.7.9.2 Emergency Room
Physician Expenditures (ERDSF00X - ERDOT00X, ERDXP00X, ERDTC00X)
Separately billing doctor (SBD) expenses typically cover
services provided to patients in hospital settings by providers like
anesthesiologists, radiologists, and pathologists, whose charges are often not
included in emergency room visit bills.
For physicians who bill separately (i.e., outside the
emergency room visit bill), a separate data collection effort within the Medical
Provider Component was performed to obtain this same set of expenditure
information from each separately billing doctor. It should be noted that there
could be several separately billing doctors associated with a medical event. For
example, an emergency room visit could have a radiologist and an internist
associated with it. If their services are not included in the emergency room
visit bill then this is one medical event with 2 separately billing doctors. The
imputed expenditure information associated with the separately billing doctors
was summed to the event level and is provided on the file. ERDSF00X - ERDOT00X
are the 12 sources of payment, ERDXP00X is the sum of the 12 sources of
payments, and ERDTC00X is the total charge.
Data users/analysts need to take into consideration
whether to analyze facility and SBD expenditures separately, combine them within
service categories, or collapse them across service categories (e.g., combine
SBD expenditures with expenditures for physician visits to offices and/or
outpatient departments).
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2.5.7.9.3 Total
Expenditures and Charges for Emergency Room Visits (ERXP00X, ERTC00X)
Data users/analysts interested in total expenditure should
use the variable ERXP00X, which includes both the facility and physician
amounts. Those interested in total charges should use the variable ERTC00X (see
section 2.5.6.1 for an explanation of the "charge" concept). However,
please note that where the emergency room visit is linked to a hospital
inpatient stay record, ERFTC00X has been zeroed out. Thus, ERTC00X may be equal
to "0" or the doctor total charge (ERDTC00X).
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2.5.8 Rounding
The expenditure variables have been rounded to the nearest
penny. Person-level expenditure information released on the MEPS 2000 Person
Level Use and Expenditure File were rounded to the nearest dollar. It should be
noted that using the MEPS 2000 event files to create person-level totals will
yield slightly different totals than those found on the person-level expenditure
file. These differences are due to rounding only. Moreover, in some instances,
the number of persons having expenditures on the event files for a particular
source of payment may differ from the number of persons with expenditures on the
person-level expenditures file for that source of payment. This difference is
also an artifact of rounding only. Please see the MEPS 2000 Appendix File,
HC-051I, for details on such rounding differences.
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3.0 Sample Weight (PERWT00F)
3.1 Overview
There is a single full year person-level weight (PERWT00F)
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 2000. 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
Weight Construction
The person-level weight PERWT00F was developed in several
stages. Person-level weights for Panels 4 and 5 were created separately. The
weighting process for each panel included an adjustment for nonresponse over
time and poststratification. Poststratification was achieved by 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. A 2000 composite weight was then formed by multiplying each panel weight by
.5 and then poststratifying the resulting weight to the same set of CPS-based
control totals. When poverty status information derived from income variables
became available, a final poststratification was done on the resulting 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 4 Weight
The person-level weight for MEPS Panel 4 was developed
using the 1999 full year weight for an individual as a "base" weight
for survey participants present in 1999. For key, in-scope respondents who
joined an RU some time in 2000 after being out-of-scope in 1999, the 1999 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
2000. These control figures were derived by scaling back the population totals
obtained from the March 2000 CPS to reflect the December 2000 CPS estimated
population distribution across age and sex categories as of December 2000.
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, 2000 is 275,158,755. Key,
responding persons not in-scope on December 31, 2000 but in-scope earlier in the
year retained, as their final Panel 4 weight, the weight after the nonresponse
adjustment.
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3.2.2 MEPS Panel 5 Weight
The person-level weight for MEPS Panel 5 was developed
using the MEPS Round 1 person-level weight as a 'base" weight. For key,
in-scope respondents who joined an 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 2000 portion of Round 3 as well
as poststratification to the same population control figures for December 2000
used for the MEPS Panel 4 weights. The same five variables employed for Panel 4
poststratification (census region, MSA status, race/ethnicity, sex, and age)
were used for Panel 5 poststratification. Similarly, for Panel 5, key,
responding persons not in-scope on December 31, 2000 but in-scope earlier in the
year retained, as their final Panel 5 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 2000 CPS database.
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3.2.3 The Final Weight for
2000
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, 2000 is 275,158,755 (PERWT00F>0 and INSC1231=1). The weights
of some persons out-of-scope on December 31, 2000 were also poststratified.
Specifically, the weights of persons out-of-scope on December 31, 2000 who were
inscope some time during the year and also entered a nursing home during the
year were poststratified to a corresponding control total obtained from the 1996
MEPS Nursing Home Component. The weights of persons who died while in-scope
during 2000 were poststratified to corresponding estimates derived using data
obtained from the Medicare Current Beneficiary Survey (MCBS) and Vital
Statistics information provided by the National Center for Health Statistics (NCHS).
Separate control totals were developed for the "65 and older" and
"under 65" civilian noninstitutionalized populations.
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3.2.4 Coverage
The target population for MEPS in this file is the 2000
U.S. civilian noninstitutionalized population. However, the MEPS sampled
households are a subsample of the NHIS households interviewed in 1998 (Panel 4)
and 1999 (Panel 5). New households created after the NHIS interviews for the
respective Panels and consisting exclusively of persons who entered the target
population after 1998 (Panel 4) or after 1999 (Panel 5) are not covered by MEPS.
Neither are previously out-of-scope persons who joined an existing household but
are unrelated to the current household residents. Persons not covered by a given
MEPS panel thus include some members of the following groups: immigrants,
persons leaving the military, U.S. citizens returning from residence in another
country, and persons leaving institutions. The set of uncovered persons
constitutes only a small proportion of the MEPS target population.
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4.0 Strategies for Estimation
This file is constructed for efficient estimation of
utilization, expenditures, and sources of payment for hospital emergency room
visits and to allow for estimates of the number of persons with emergency room
visits for 2000.
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4.1 Variables with Missing
Values
It is essential that the analyst examine all variables for
the presence of negative values used to represent missing values. For continuous
or discrete variables, where means or totals may be taken, it may be necessary
to set minus values to values appropriate to the analytic needs. That is, the
analyst should either impute a value or set the value to one that will be
interpreted as missing by the computing language used. For categorical and
dichotomous variables, the analyst may want to consider whether to recode or
impute a value for cases with negative values or whether to exclude or include
such cases in the numerator and/or denominator when calculating proportions.
Methodologies used for the editing/imputation of
expenditure variables (e.g., sources of payment, flat fee, hospital/ER, and zero
expenditures) are described in Section 2.5.6.2.
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4.2 Basic Estimates of
Utilization, Expenditures and Sources of Payment
While the examples described below illustrate the use of
event-level data in constructing person-level total expenditures, these
estimates can also be derived from the person-level expenditure file unless the
characteristic of interest is event specific.
In order to produce national estimates related to
emergency room visits, expenditures, and sources of payment, the value in each
record contributing to the estimates must be multiplied by the weight (PERWT00F)
contained on that record.
Example 1
For example, the total number of emergency room visits for
the civilian noninstitutionalized population of the U.S. in 2000 is estimated as
the sum of the weight (PERWT00F) across all emergency room visit records. That
is,
301 Moved Permanently
301 Moved Permanently
|
= 46,921,296 |
(1) |
Example 2
Subsetting to records based on characteristics of interest
expands the scope of potential estimates. For example, the estimate for the mean
out-of-pocket payment for emergency room visits (for those who had such expense
greater than 0) should be calculated as the weighted mean of the facility bill
and doctor's bill paid by self/family. That is,
301 Moved Permanently
301 Moved Permanently
|
= $55.04 |
(2) |
where Xj = ERFSF00Xj + ERDSF00Xj
and |
301 Moved Permanently
301 Moved Permanently
|
= 42,830,986 |
for all records with ERXP00Xj > 0.
This gives $55.04 as the estimated mean amount of
out-of-pocket payment of expenditures associated with emergency room visits and
42,830,986 as an estimate of the total number of such emergency room visits with
expenditures. Both of these estimates are for the civilian noninstitutionalized
population of the U.S. in 2000.
Example 3
Another example would be to estimate the mean proportion
of total expenditures paid by private insurance for emergency room visits with
expenditure. This should be calculated as the weighted mean of the proportion of
total expenditures paid by private insurance at the event level. That is,
301 Moved Permanently
301 Moved Permanently
|
= 0.4144 |
(3) |
where Yj = (ERFPV00Xj + ERDPV00Xj)/ERXP00Xj
and |
301 Moved Permanently
301 Moved Permanently
|
= 42,830,986 |
for all emergency room visit records with ERXP00Xj >
0.
This gives 0.4144as the estimated mean proportion of total
expenditures paid by private insurance for emergency room visits with
expenditure for the civilian noninstitutionalized population of the U.S. in
2000.
Return To Table Of Contents
4.3 Estimates of the Number
of Persons with Emergency Room Visit Events
When calculating an estimate of the total number of
persons with emergency room visits, users can use a person-level file or this
event file. However, this event file must be used when the measure of interest
is defined at the event level. For example, to estimate the number of persons in
the civilian noninstitutionalized population of the U.S. with emergency room visits where the patient sees a doctor,
this event file must be used. This would be estimated as
301 Moved Permanently
301 Moved Permanently
|
across all
unique persons i on this file |
(4) |
where
Wi is the sampling weight (PERWT00F)
for person i
and
Xi = 1 if SEEDOCj = 1 for any
emergency room visit record of person i
= 0 otherwise.
Return To Table Of Contents
4.4 Person-Based Ratio
Estimates
4.4.1 Person-Based Ratio
Estimates Relative to Persons with Emergency Room Use
This file may be used to derive person-based ratio
estimates. However, when calculating ratio estimates where the denominator is at
the person level, care should be taken to properly define and estimate the unit
of analysis as person-level. For example, the mean expense for persons with
emergency room visits is estimated as
301 Moved Permanently
301 Moved Permanently
|
across all unique persons i on
this file |
(5) |
where
Wi is the sampling weight (PERWT00F)for person i
and
Zi = |
301 Moved Permanently
301 Moved Permanently
|
ERXP00Xj
across all
emergency room visits for person i. |
Return To Table Of Contents
4.4.2 Person-Based Ratio
Estimates Relative to the Entire Population
If the ratio relates to the entire population, this file
cannot be used to calculate the denominator, as only those persons with at least
one emergency room visit are represented on this data file. In this case, the
Full Year Consolidated File, which has data for all sampled persons, must be
used to estimate the total number of persons (i.e., those with use and those
without use). For example, to estimate the proportion of the civilian
noninstitutionalized population of the U.S. with at least one emergency room
visit where the person saw a doctor, the numerator would be derived from data on
this event file, and the denominator would be derived from data on the
person-level file. That is,
301 Moved Permanently
301 Moved Permanently
|
across
all unique persons i on the person-level file |
(6) |
where
Wi is the sampling weight (PERWT00F)for person i
and
Zi = 1 if SEEDOCj = 1
for any emergency room visit of person i
= 0 otherwise.
Return To Table Of Contents
4.5 Sampling Weights for
Merging Previous Releases of MEPS Household Data with this Event File
There have been several previous releases of MEPS
Household Survey public use data. Unless a variable name common to several files
is provided, the sampling weights contained on these data files are
file-specific. The file-specific weights reflect minor adjustments to
eligibility and response indicators due to birth, death, or institutionalization
among respondents.
For estimates from a MEPS data file that do not require
merging with variables from other MEPS data files, the sampling weight(s)
provided on that data file are the appropriate weight(s). When merging a MEPS
Household data file to another, the major analytical variable (i.e., the
dependent variable) determines the correct sampling weight to use.
Return To Table Of Contents
4.6 Variance Estimation
(VARSTR00, VARPSU00)
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 2000 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 VARSTR00
and VARPSU00, 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.
The following illustrates these concepts using two examples from Section 4.2.
Examples 2 and 3 from Section 4.2
Using a Taylor Series approach, specifying VARSTR00 and
VARPSU00 as the variance estimation strata and PSUs (within these strata)
respectively and specifying a "with replacement" design in a computer
software package (i.e., SUDAAN) will yield standard error estimates of $3.99 and
0.0131 for the estimated mean of out-of-pocket payment and the estimated mean
proportion of total expenditures paid by private insurance respectively.
Return To Table Of Contents
5.0
Merging/Linking MEPS Data Files
Data from the 2000 Emergency Room Visits File can be used
alone or in conjunction with other files. This section provides instructions for
linking the emergency room visits file with other MEPS public use files, namely,
the person-level file, the prescribed medicines file, and the conditions file.
Return To Table Of Contents
5.1 Merging a 2000
Person-Level File to the 2000 Emergency Room Visit File
Merging characteristics of interest from person-level
files (e.g., MEPS 2000 Full Year Population Characteristics File, or MEPS 2000
Person Level Use and Expenditure File) expands the scope of potential estimates.
To estimate the total number of emergency room visits for persons with specific
demographic characteristics (e.g., age, race, and sex), population
characteristics from a person-level file need to be merged onto the emergency
room visit file. This procedure is illustrated below. The MEPS 2000 Appendix
File, HC-051I, provides additional detail on how to merge MEPS data files.
- Create data set PERSX by sorting the MEPS 2000 Full
Year Population Characteristics File by the person identifier, DUPERSID.
Keep only variables to be merged onto the emergency room visit file and
DUPERSID.
- Create data set EROM by sorting the emergency room
visit file by person identifier, DUPERSID.
- Create final data set NEWEROM by merging these two
files by DUPERSID, keeping only records on the emergency room visit file.
The following is an example of SAS code which
completes these steps:
PROC SORT DATA=2000 Full Year Population
Characteristics File
(KEEP= DUPERSID AGE31X AGE42X AGE53X SEX RACEX
EDUCYR) OUT=PERSX;
BY DUPERSID;
RUN;
PROC SORT DATA=EROM;
BY DUPERSID;
RUN;
DATA NEWEROM;
MERGE EROM (IN=A)
PERSX(IN=B);
BY DUPERSID;
IF A;
RUN;
Return To Table Of Contents
5.2
Linking the 2000 Emergency Room Visits File to the 2000 Medical
Conditions File and/or the 2000 Prescribed Medicines File
Due to survey design issues, data users/analysts must keep
limitations and caveats in mind when linking the different files. Those
limitations/caveats are listed below. For detailed linking examples, including
SAS code, data users/analysts should refer to the MEPS 2000 Appendix File,
HC-051I.
Return To Table Of Contents
5.2.1 Limitations/Caveats of
RXLK (the Prescribed Medicine Link File)
The RXLK file provides a link from the MEPS event files to
the 2000 Prescribed Medicine File. When using RXLK, data users/analysts should
keep in mind that one emergency room visit can link to more than one prescribed
medicine record. Conversely, a prescribed medicine event may link to more than
one emergency room visit or different types of events. When this occurs, it is
up to the data user/analyst to determine how the prescribed medicine
expenditures should be allocated among those medical events.
Return To Table Of Contents
5.2.2
Limitations/Caveats of CLNK (the Medical Conditions Link File)
The CLNK provides a link from MEPS event files to the 2000
Medical Conditions File. When using the CLNK, data users/analysts should keep in
mind that (1) conditions are self-reported and (2) there may be multiple
conditions associated with an emergency room visit. Data users/analysts should
also note that not all emergency room visits link to the medical conditions
file.
Return To Table Of Contents
References
Cohen, S.B. (1998). Sample Design of the 1996 Medical
Expenditure Panel Survey Medical Provider Component. Journal of Economic
Social Measurement. Vol. 24, 25-53.
Cohen, S.B. (1997). Sample Design of the 1996 Medical
Expenditure Panel Survey Household Component. Rockville (MD): Agency for Health
Care Policy and Research; 1997. MEPS Methodology Report, No. 2.
AHCPR Pub. No. 97-0027.
Cohen, J.W. (1997). Design and Methods of the Medical
Expenditure Panel Survey Household Component. Rockville (MD): Agency for Health
Care Policy and Research; 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.
Cox, B.G. and Cohen, S.B. (1985). Chapter 6: A Comparison
of Household and Provider Reports of Medical Conditions. In Methodological
Issues for Health Care Surveys. Marcel Dekker, New York.
Cox, B. and Iachan, R. (1987). A Comparison of Household
and Provider Reports of Medical Conditions. Journal of Economic and Social
Measurement. 82(400):1013-18.
Edwards, W.S., Winn, D.M., Kurlantzick V., et al. (1994).
Evaluation of National Health Interview Survey Diagnostic Reporting. National
Center for Health Statistics, Vital Health 2(120).
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 Health Care Policy and Research; 1998.
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, A.E. and Sanchez, M.E. (1993). Household and
Medical Provider Reports on Medical Conditions: National Medical Expenditure
Survey, 1987. Journal of Economic and Social Measurement. Vol. 19,
199-233.
Monheit, A.C., Wilson, R., and Arnett, III, R.H.
(Editors). Informing American Health Care Policy. (1999). Jossey-Bass Inc., San
Francisco.
Shah, B.V., Barnwell, B.G., Bieler, G.S., Boyle, K.E.,
Folsom, R.E., Lavange, L., Wheeless, S.C., and Williams, R. (1996). Technical
Manual: Statistical Methods and Algorithms Used in SUDAAN Release 7.0,
Research Triangle Park, NC: Research Triangle Institute.
Return To Table Of Contents
D. Variable-Source
Crosswalk
Variable-Source
Crosswalk
For MEPS HC-051E: 2000 Emergency Room
Visits
Survey Administration Variables
Variable |
Description |
Source |
DUID |
Dwelling unit ID |
Assigned in sampling |
PID |
Person number |
Assigned in sampling |
DUPERSID |
Person ID (DUID+PID) |
Assigned in sampling |
EVNTIDX |
Event ID |
Assigned in Sampling |
EVENTRN |
Event round number |
CAPI derived |
ERHEVIDX |
Event ID for corresponding hospital stay |
Constructed |
FFEEIDX |
Flat fee ID |
CAPI derived |
MPCDATA |
MPC data flag |
Constructed |
Return To Table Of Contents
Emergency Room Visit Event Variables
Variable |
Description |
Source |
ERDATEYR |
Event date - year |
CAPI derived |
ERDATEMM |
Event date - month |
CAPI derived |
ERDATEDD |
Event date - day |
CAPI derived |
SEEDOC |
Did person talk to MD this visit |
ER01 |
VSTCTGRY |
Best category for care person receive on visit date |
ER02 |
VSTRELCN |
Was this visit related to spec hlth cond |
ER03 |
LABTEST |
This visit did person have lab tests |
ER05 |
SONOGRAM |
This visit did person have sonogram or ultrasound |
ER05 |
XRAYS |
This visit did person have x-rays |
ER05 |
MAMMOG |
This visit did person have a mammogram |
ER05 |
MRI |
This visit did person have an MRI/Catscan |
ER05 |
EKG |
This visit did person have an EKG or ECG |
ER05 |
EEG |
This visit did person have an EEG |
ER05 |
RCVVAC |
This visit did person receive a vaccination |
ER05 |
ANESTH |
This visit did person receive anesthesia |
ER05 |
OTHSVCE |
This visit did person have other diagnostic tests or
exams |
ER05 |
SURGPROC |
Was a surgical procedure performed on person this
visit |
ER06 |
SURGNAME |
Surgical procedure name in categories |
ER07 |
MEDPRESC |
Any medicine prescribed for person this visit |
ER08 |
VAPLACE |
VA facility flag |
Constructed |
ERICD1X |
3-digit ICD-9 condition code |
Edited |
ERICD2X |
3-digit ICD-9 condition code |
Edited |
ERICD3X |
3-digit ICD-9 condition code |
Edited |
ERPRO1X |
2-digit ICD-9 procedure code |
Edited |
ERCCC1X |
Modified Clinical Classification Code |
Constructed/Edited |
ERCCC2X |
Modified Clinical Classification Code |
Constructed/Edited |
ERCCC3X |
Modified Clinical Classification Code |
Constructed/Edited |
Return To Table Of Contents
Flat Fee Variables
Variable |
Description |
Source |
FFERTYPE |
Flat fee bundle |
Constructed |
FFBEF00 |
Total # of visits in FF before 2000 |
FF05 |
FFTOT01 |
Total # of visits in FF after 2000 |
FF10 |
Return To Table Of Contents
Imputed Total Expenditure Variables
Variable |
Description |
Source |
ERXP00X |
Total expenditure for event (ERFXP00X + ERDXP00X) |
Constructed |
ERTC00X |
Total charge for event (ERFTC00X + ERDTC00X) |
Constructed |
Return To Table Of Contents
Imputed Facility Expenditure Variables
Variable |
Description |
Source |
ERFSF00X |
Facility amount paid, family (Imputed) |
CP Section (Edited) |
ERFMR00X |
Facility amount paid, Medicare (Imputed) |
CP Section (Edited) |
ERFMD00X |
Facility amount paid, Medicaid (Imputed) |
CP Section (Edited) |
ERFPV00X |
Facility amount paid, private insurance (Imputed) |
CP Section (Edited) |
ERFVA00X |
Facility amount paid, Veterans
Administration(Imputed) |
CP Section (Edited) |
ERFTR00X |
Facility amount paid, TRICARE (Imputed) |
CP Section (Edited) |
ERFOF00X |
Facility amount paid, other federal (Imputed) |
CP Section (Edited) |
ERFSL00X |
Facility amount paid, state & local government
(Imputed) |
CP Section (Edited) |
ERFWC00X |
Facility amount paid, Workers' Compensation
(Imputed) |
CP Section (Edited) |
ERFOR00X |
Facility amount paid, other private insurance
(Imputed) |
Constructed |
ERFOU00X |
Facility amount paid, other public insurance
(Imputed) |
Constructed |
ERFOT00X |
Facility amount paid, other insurance (Imputed) |
CP Section (Edited) |
ERFXP00X |
Facility sum payments ERFSF00X - ERFOT00X |
Constructed |
ERFTC00X |
Total facility charge (Imputed) |
CP Section (Edited) |
Return To Table Of Contents
Imputed Physician Expenditure Variables
Variable |
Description |
Source |
ERDSF00X |
Doctor amount paid, family (Imputed) |
Constructed |
ERDMR00X |
Doctor amount paid, Medicare (Imputed) |
Constructed |
ERDMD00X |
Doctor amount paid, Medicaid (Imputed) |
Constructed |
ERDPV00X |
Doctor amount paid, private insurance (Imputed) |
Constructed |
ERDVA00X |
Doctor amount paid, Veterans (Imputed) |
Constructed |
ERDTR00X |
Doctor amount paid, TRICARE (Imputed) |
Constructed |
ERDOF00X |
Doctor amount paid, other federal (Imputed) |
Constructed |
ERDSL00X |
Doctor amount paid, state & local government
(Imputed) |
Constructed |
ERDWC00X |
Doctor amount paid, Workers' Comp (Imputed) |
Constructed |
ERDOR00X |
Doctor amount paid, other private insurance
(Imputed) |
Constructed |
ERDOU00X |
Doctor amount paid, other public insurance (Imputed) |
Constructed |
ERDOT00X |
Doctor amount paid, other insurance (Imputed) |
Constructed |
ERDXP00X |
Doctor sum payments ERDSF00X - ERDOT00X |
Constructed |
ERDTC00X |
Total doctor charge (Imputed) |
Constructed |
IMPFLAG |
Imputation status |
Constructed |
Return To Table Of Contents
Weights
Variable |
Description |
Source |
PERWT00F |
Final person level weight, 2000 |
Constructed |
VARSTR00 |
Variance estimation stratum, 2000 |
Constructed |
VARPSU00 |
Variance estimation PSU, 2000 |
Constructed |
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