MEPS HC-135E: 2010 Emergency Room Visits
July 2012
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 Survey Management and Data Collection
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)
2.5.1.4 Panel Indicator (PANEL)
2.5.2 MPC Data Indicator (MPCDATA)
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 Condition and Procedure Codes (ERICD1X-ERICD3X, ERPRO1X, ERPRO2X), and Clinical Classification Codes (ERCCC1X-ERCCC3X)
2.5.5 Flat Fee Variables (FFEEIDX, FFERTYPE, FFBEF10, FFTOT11)
2.5.5.1 Definition of Flat Fee Payments
2.5.5.2 Flat Fee Variable Descriptions
2.5.5.2.1 Flat Fee ID (FFEEIDX)
2.5.5.2.2 Flat Fee Type (FFERTYPE)
2.5.5.2.3 Counts of Flat Fee Events that Cross Years (FFBEF10, FFTOT11)
2.5.5.3 Caveats of Flat Fee Groups
2.5.6 Expenditure Data
2.5.6.1 Definition of Expenditures
2.5.6.2 Data Editing and Imputation Methodologies of Expenditure Variables
2.5.6.2.1 General Data Editing Methodology
2.5.6.2.2 Imputation Methodologies
2.5.6.2.3 Emergency Room Visit Data Editing and Imputation
2.5.6.3 Imputation Flag (IMPFLAG)
2.5.6.4 Flat Fee Expenditures
2.5.6.5 Zero Expenditures
2.5.6.6 Discount Adjustment Factor
2.5.6.7 Emergency Room/Hospital Inpatient Stay Expenditures
2.5.6.8 Sources of Payment
2.5.6.9 Imputed Emergency Room Expenditure Variables
2.5.6.9.1 Emergency Room Facility Expenditures (ERFSF10X-ERFOT10X, ERFXP10X, ERFTC10X)
2.5.6.9.2 Emergency Room Physician Expenditures (ERDSF10X - ERDOT10X, ERDXP10X, ERDTC10X)
2.5.6.9.3 Total Expenditures and Charges for Emergency Room Visits (ERXP10X, ERTC10X)
2.5.7 Rounding
3.0 Sample Weight (PERWT10F)
3.1 Overview
3.2 Details on Person Weight Construction
3.2.1 MEPS Panel 14 Weight
3.2.2 MEPS Panel 15 Weight
3.2.3 The Final Weight for 2010
3.2.4 Coverage
3.3 Using MEPS Data for Trend Analysis
4.0 Strategies for Estimation
4.1 Developing Event-Level Estimates
4.2 Person-Based Estimates for Emergency Room Visits
4.3 Variables with Missing Values
4.4 Variance Estimation (VARPSU, VARSTR)
5.0 Merging/Linking MEPS Data Files
5.1 Linking to the Person-Level File
5.2 Linking to the Prescribed Medicines File
5.3 Linking to the Medical Conditions File
_._ References
D. Variable-Source Crosswalk
A. Data Use Agreement
Individual identifiers have been removed from the
micro-data contained in these files. 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; and
- 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
- 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
1.0 Household Component
The Medical Expenditure Panel Survey (MEPS) provides
nationally representative estimates of health care use, expenditures, sources of
payment, and health insurance coverage for the U.S. civilian
non-institutionalized population. The MEPS Household Component (HC) also
provides estimates of respondents’ health status, demographic and socio-economic
characteristics, employment, access to care, and satisfaction with health care.
Estimates can be produced for individuals, families, and selected population
subgroups. The panel design of the survey, which includes 5 Rounds of interviews
covering 2 full calendar years, provides data for examining person level changes
in selected variables such as expenditures, health insurance coverage, and
health status. Using computer assisted personal interviewing (CAPI) technology,
information about each household member is collected, and the survey builds on
this information from interview to interview. All data for a sampled household
are reported by a single household respondent.
The MEPS-HC was initiated in 1996. Each year a new
panel of sample households is selected. Because the data collected are
comparable to those from earlier medical expenditure surveys conducted in 1977
and 1987, it is possible to analyze long-term trends. Each annual MEPS-HC sample
size is about 15,000 households. Data can be analyzed at either the person or
event level. Data must be weighted to produce national
estimates.
The set of households selected for each panel of the
MEPS HC is a subsample of households participating in the previous year’s
National Health Interview Survey (NHIS) conducted by the National Center for
Health Statistics. The NHIS sampling frame provides a nationally representative
sample of the U.S. civilian non-institutionalized population and reflects an
oversample of blacks and Hispanics. In 2006, the NHIS implemented a new sample
design, which included Asian persons in addition to households with black and
Hispanic persons in the oversampling of minority populations. MEPS further
oversamples additional policy relevant sub-groups such as low income households.
The linkage of the MEPS to the previous year’s NHIS provides additional data for
longitudinal analytic purposes.
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2.0 Medical Provider Component
Upon completion of the household CAPI interview and
obtaining permission from the household survey respondents, a sample of medical
providers are contacted by telephone to obtain information that household
respondents can not accurately provide. This part of the MEPS is called the
Medical Provider Component (MPC) and information is collected on dates of visit,
diagnosis and procedure codes, charges and payments. The Pharmacy Component
(PC), a subcomponent of the MPC, does not collect charges or diagnosis and
procedure codes but does collect drug detail information, including National
Drug Code (NDC) and medicine name, as well as date filled and sources and
amounts of payment. The MPC is not designed to yield national estimates. It is
primarily used as an imputation source to supplement/replace household reported
expenditure information.
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3.0 Survey Management and Data Collection
MEPS HC and MPC data are collected under the authority
of the Public Health Service Act. Data are collected under contract with Westat,
Inc. (MEPS HC) and Research Triangle Institute (MEPS MPC). Data sets and summary
statistics are edited and published in accordance with the confidentiality
provisions of the Public Health Service Act and the Privacy Act. The National
Center for Health statistics (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, micro data files, and tables via the MEPS Web site:
meps.ahrq.gov.
Selected data can be analyzed through MEPSnet, an on-line interactive tool
designed to give data users the capability to statistically analyze MEPS data in
a menu-driven environment.
Additional information on MEPS is available from the
MEPS project manager or the MEPS public use data manager at the Center for
Financing, Access, and Cost Trends, Agency for Healthcare Research and Quality,
540 Gaither Road, Rockville, MD 20850 (301-427-1406).
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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 2010 Medical Expenditure Panel
Survey (MEPS) Household Component (HC) and Medical Provider Component (MPC).
Released as an ASCII data file (with related SAS, Stata, and SPSS programming
statements) and a SAS transport file, the 2010 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 2010. The file contains 70 variables and
has a logical record length of 354 with an additional 2-byte carriage
return/line feed at the end of each record. As illustrated below, this file
consists of MEPS survey data from the 2010 portion of Round 3, and Rounds 4 and
5 for Panel 14, as well as Rounds 1, 2 and the 2010 portion of Round 3 for Panel
15 (i.e., the rounds for the MEPS panels covering calendar year 2010).
Emergency room events reported in Panel 15 Round 3 and
known to have occurred after December 31, 2010 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.
Annual counts of emergency room visits are based
entirely on household reports. Information from the MEPS MPC is used to
supplement expenditure and payment data reported by the household and does not
affect use estimates.
Data from the Emergency Room event file can be merged
with other 2010 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 is provided on the MEPS 2010 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 Weight
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 T.
Ezzati-Rice, et al. (1998-2007) 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 Questionnaires section of the MEPS Web site at the following
address: meps.ahrq.gov.
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2.0 Data File Information
The 2010 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.
The 2010 EROM public use data set contains variables
and frequency distributions for 5,516 emergency room visits reported during the
2010 portion of Round 3 and Rounds 4 and 5 for Panel 14, as well as Rounds 1, 2,
and the 2010 portion of Round 3 for Panel 15 of the MEPS Household Component.
This file includes emergency room visit records for all household survey members
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, 2010 are not included on this file. Of these 5,516
records, 5,310 were associated with persons having positive person-level weights
(PERWT10F). 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 2010 eligibility (i.e., persons with a
positive 2010 full-year person-level weight (PERWT10F > 0)), or
- Be an eligible member of a family all of whose key in-scope
members have a positive person-level weight (PERWT10F > 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 (FAMWT10F >0). Note that FAMIDYR and
FAMWT10F are variables on the 2010 Population Characteristics file.
Persons with no emergency room visit events for 2010
are not included on this event-level ER file but are represented on the
person-level 2010 Full Year Population Characteristics file.
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; a full-year
person-level weight; variance strata; and variance PSU.
To append person-level information such as demographic
or health insurance coverage to each event record, data from this file can be
merged with 2010 MEPS HC person-level data (e.g. Full Year Consolidated or Full
Year Population Characteristics files) using the person identifier, DUPERSID.
Emergency room visit events can also be linked to the MEPS 2010 Medical
Conditions File and the MEPS 2010 Prescribed Medicines File. Please see Section
5.0 and the 2010 Appendix File, HC-135I for details on how to merge MEPS data
files.
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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 accompanying codebook.
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-CM condition and procedure codes
Clinical Classification Software (CCS) codes
Imputed expenditure variables
Weight and variance estimation variables
Note that the person identifier is unique within this
data year.
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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:
meps.ahrq.gov/survey_comp/survey_questionnaires.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 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
ER - emergency room visit
HH - home health event
OM - other medical equipment
OB - office-based visit
OP - outpatient visit
DV - dental visit
RX - prescribed medicine
For expenditure variables on the ER file, 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
MR - Medicare
MD - Medicaid
PV - private insurance
VA - Veterans Administration/CHAMPVA
TR - TRICARE
OF - other Federal Government
SL - State/local government
WC - Workers’ Compensation
OT - other insurance
OR - other private
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
(10). The eighth character, "X", indicates whether the variable is
edited/imputed.
For example, ERFSF10X 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 2010 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 2010 Medical Conditions File and
the MEPS 2010 Prescribed Medicines File, respectively). For details on linking,
see Section 5.0 or the MEPS 2010 Appendix File, HC-135I.
ERHEVIDX is a constructed variable identifying an EROM
record that has its facility expenditures represented on an associated hospital
inpatient stay record. This variable is derived from provider-reported
information on linked emergency room and inpatient stay events that matched to
corresponding events reported by the household. The variable ERHEVIDX contains
the EVNTIDX of the linked event. On the 2010 EROM file, there are 314 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.
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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 14. Likewise, Round 1, 2, and 3 are
associated with data collected from Panel 15.
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2.5.1.4 Panel Indicator (PANEL)
PANEL is a constructed variable used to specify the
panel number for the person. PANEL will indicate either Panel 14 or Panel 15 for
each person on the file. Panel 14 is the panel that started in 2009, and Panel
15 is the panel that started in 2010.
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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 year, month, and day of the emergency room visit was
recorded (ERDATEYR, ERDATEMM, and ERDATEDD, respectively). 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), throat swab (THRTSWAB), or other diagnostic tests or exams
(OTHSVCE). Whether or not a surgical procedure was performed during the visit
was asked (SURGPROC). 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 Condition and Procedure Codes (ERICD1X-ERICD3X,
ERPRO1X, ERPRO2X), and Clinical Classification Codes (ERCCC1X-ERCCC3X)
Information on household reported medical conditions
and procedures associated with each emergency room visit is provided on this
file. There are up to three condition and CCS codes (ERICD1X-ERICD3X,
ERCCC1X-ERCCC3X) and up to two procedure codes (ERPRO1X, ERPRO2X) 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 2010
Medical Conditions File. Details on how to link the 2010 EROM event file to the
MEPS 2010 Medical Conditions File are provided in Section 5.3 and the MEPS 2010
Appendix File, HC-135I. 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 2010 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
2.5 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 2010 Medical Conditions File. For frequencies
of conditions by event type, please see the MEPS 2010 Appendix File, HC-135I.
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
mutually exclusive categories, most of which are clinically homogeneous.
In order to preserve member 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. Similarly, the procedure codes
have been collapsed from fully-specified codes to two-digit code categories.
Because of this collapsing, it is possible for there to be duplicate ICD-9-CM
condition or procedure codes linked to a single medical event when different
fully-specified codes are collapsed into the same code. For more information
on ICD-9-CM codes, see the HC-137 documentation.
The condition codes, and clinical classification 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 2010 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.
Analysts should use the clinical classification codes
listed in the Conditions PUF document (HC-137) and the Appendix to the Event
Files (HC-135I) document when analyzing MEPS conditions data. Although there is
a list of clinical classification codes and labels on the Healthcare Cost and
Utilization Project (HCUP) Web site, if updates to these codes and/or labels are
made on the HCUP Web site after the release of the 2010 MEPS PUFs, these updates
will not be reflected in the 2010 MEPS data.
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2.5.5 Flat Fee Variables (FFEEIDX,
FFERTYPE, FFBEF10, FFTOT11)
2.5.5.1 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. 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 2010. By
definition, a flat fee group can span multiple years. Furthermore, a single
person can have multiple flat fee groups.
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2.5.5.2 Flat Fee Variable Descriptions
2.5.5.2.1 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 2010 MEPS event file, every
event that was a 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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2.5.5.2.2 Flat Fee Type (FFERTYPE)
FFERTYPE indicates whether the 2010 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, the FFERTYPE is set to –1,
"INAPPLICABLE."
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2.5.5.2.3 Counts of Flat Fee Events
that Cross Years (FFBEF10, FFTOT11)
As described in Section 2.5.5.1, a flat fee payment
may cover multiple events, and the multiple events could span multiple years.
For situations where the emergency room event occurred in 2010 as part of a
group of events, and some event occurred before or after 2010, counts of the
known events are provided on the emergency room record. Variables indicating
events that occurred before or after 2010 are as follows:
FFBEF10 – total number of pre-2010 events in the same
flat fee group as the 2010 emergency room visit(s). This count would not include
the 2010 emergency room visit(s). Because there were no 2009 events for any flat
fee group, this variable was omitted from this file.
FFTOT11 –the number of 2011 emergency room visits,
expected to be in the same flat fee group as the emergency room event that
occurred in 2010. Because there were no 2011 events expected for any flat fee
group, this variable was omitted from this file.
If there are no 2009 events on the file, FFBEF10 will
be omitted. Likewise, if there are no 2011 events on the file, FFTOT11 will be
omitted. If there are no flat fee data related to the records in this file,
FFEEIDX and FFERTYPE will be omitted as well. Please note that the crosswalk in
this document lists all possible flat fee variables.
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2.5.5.3 Caveats of Flat Fee Groups
There are 10 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 2010, but the remaining visits that were part
of this flat fee group occurred in 2011. In this case, the 2010 flat fee group
represented on this file would consist of one event, the stem. The 2011 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 2009 but subsequent visits occurred during 2010. In this case,
the initial visit would not be represented on the file. This 2010 flat fee group
would then only consist of one or more leaf records and no stem.
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2.5.6 Expenditure Data
2.5.6.1 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 1990s 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 accessed via the CFACT
data center. For more information, see the Data Center section of the MEPS Web
site meps.ahrq.gov.
Expenditure data related to emergency room visits are
broken out by facility and separately billing doctor expenditures. This file
contains six 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 charge; physician charge, and total charges, which is the sum
of the facility and physician charges. If examining trends in MEPS expenditures,
please refer to Section 3.3 for more information.
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2.5.6.2 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 available; otherwise, HC data were used. Missing
data for emergency room visits, where HC data were not complete and MPC data
were not collected, or MPC data were not complete, were imputed through the
imputation process.
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2.5.6.2.1 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 misclassifications 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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2.5.6.2.2 Imputation Methodologies
The predictive mean matching imputation method was
used to impute missing expenditures. This procedure uses regression models
(based on events with completely reported expenditure data) to predict total
expenses for each event. Then, for each event with missing payment information,
a donor event with the closest predicted payment with the same pattern of
expected payment sources as the event with missing payment was used to impute
the missing payment value. The weighted sequential hot-deck procedure was used
to impute the missing total charges. This procedure uses survey data from
respondents to replace missing data while taking into account the persons’
weighted distribution in the imputation process.
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2.5.6.2.3 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 predictive
mean matching 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 person 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 predictive mean matching imputations, while
events with missing expenditure data were assigned to various recipient
categories. Each event with missing expenditure data 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 predictive
mean matching imputations were performed on events in each recipient category.
For hospital inpatient and emergency room events, the donor pool
was restricted to events with complete expenditures from the MPC. Due to the low
ratio of donors to recipients for hospital outpatient and office-based
events, there were no donor pool restrictions.
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 distribution of free event among complete events (donors) would not be
represented among incomplete events (recipients).
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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2.5.6.3 Imputation Flag (IMPFLAG)
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 flat fee 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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2.5.6.4 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 facility payments, while physician’s expenditures may
still be present. Thus, if the first visit in the flat fee group occurred prior
to 2010, all of the events that occurred in 2010 will have zero payments.
Conversely, if the first event in the flat fee group occurred at the end of
2010, the total expenditure for the entire flat fee group will be on that event,
regardless of the number of events it covered after 2010. See Section 2.5.5 for
details on the flat fee variables.
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2.5.6.5 Zero Expenditures
There are some medical events reported by respondents
where the payments were zero. Zero payment events can occur in MEPS for the
following reasons: (1) the stay was covered under a flat fee arrangement (flat
fee payments are included only on the first event covered by the arrangement),
(2) there was no charge for a follow-up stay, (3) the provider was never paid by
an individual, insurance plan, or other source for services provided, (4)
charges were included in the bill for a subsequent hospital admission (emergency
room events only), or (5) the event was paid for through government or
privately-funded research or clinical trials.
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2.5.6.6 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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2.5.6.7 Emergency Room/Hospital
Inpatient Stay Expenditures
It is common for an emergency room visit to result in
a hospital stay. 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 the 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 is included in 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 2010 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 facility 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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2.5.6.8 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/CHAMPVA,
- TRICARE,
- 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, and liability insurance, 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 these two sources are 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
public payer.
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2.5.6.9 Imputed Emergency Room Expenditure Variables
This file contains two sets of imputed expenditure
variables: facility expenditures and physician expenditures.
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2.5.6.9.1 Emergency Room Facility Expenditures
(ERFSF10X-ERFOT10X, ERFXP10X, ERFTC10X)
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.
ERFSF10X - ERFOT10X are the 12 sources of payment. The
12 sources of payment are: self/family (ERFSF10X), Medicare (ERFMR10X), Medicaid
(ERFMD10X), private insurance (ERFPV10X), Veterans Administration/CHAMPVA
(ERFVA10X), TRICARE (ERFTR10X), other Federal sources (ERFOF10X), State and
Local (non-federal) government sources (ERFSL10X), Worker’s Compensation
(ERFWC10X), other private insurance (ERFOR10X), other public insurance
(ERFOU10X), and other insurance (ERFOT10X). ERFXP10X is the sum of the 12
sources of payment for the Emergency Room expenditures, and ERFTC10X is the
total charge. Please note that where an emergency room visit record is linked to
a hospital inpatient stay record, all facility sources of payment variables, as
well as ERFTC10X, have been zeroed out.
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2.5.6.9.2 Emergency Room Physician Expenditures
(ERDSF10X - ERDOT10X, ERDXP10X, ERDTC10X)
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 two 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. ERDSF10X -
ERDOT10X are the 12 sources of payment, ERDXP10X is the sum of the 12 sources of
payments, and ERDTC10X is the physician’s 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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2.5.6.9.3 Total Expenditures and
Charges for Emergency Room Visits (ERXP10X, ERTC10X)
Data users/analysts interested in total expenditure
should use the variable ERXP10X, which includes both the facility and physician
amounts. Those interested in total charges should use the variable ERTC10X,
which includes both facility and physician charges (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, ERFTC10X has
been zeroed out. Thus, ERTC10X may be equal to "0" or the doctor total charge
(ERDTC10X).
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2.5.7 Rounding
The expenditure variables have been rounded to the
nearest penny. Person-level expenditure information released on the MEPS 2010
Person-Level Use and Expenditure File were rounded to the nearest dollar. It
should be noted that using the MEPS 2010 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 2010
Appendix File, HC-135I, for details on such rounding differences.
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3.0 Sample Weight (PERWT10F)
3.1 Overview
There is a single full year person-level weight
(PERWT10F) 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 2010. A
key person either was a member of a responding NHIS household at the time of
interview, or joined a family associated with such a household after being
out-of-scope at the time of the NHIS (the latter circumstance includes newborns
as well as those returning from military service, an institution, or residence
in a foreign country). 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 PERWT10F was developed in
several stages. Person-level weights for Panel 14 and Panel 15 were created
separately. The weighting process for each panel included an adjustment for
nonresponse over time and calibration to independent population figures. The
calibration was initially accomplished separately for each panel by raking the
corresponding sample weights to Current Population Survey (CPS) population
estimates based on five variables. The five variables used in the establishment
of the initial person-level control figures were: census region (Northeast,
Midwest, South, West); MSA status (MSA, non-MSA); race/ethnicity (Hispanic;
black, non-Hispanic; Asian, non-Hispanic; and other);
sex; and age. A 2010 composite weight was then formed by multiplying each weight
from Panel 14 by the factor .51 and each weight from Panel 15 by the factor .49.
The choice of factors reflected the relative sample sizes of the two panels,
helping to limit the variance of estimates obtained from pooling the two
samples. The composite weight was again raked to the same set of CPS-based
control totals. When poverty status information derived from income variables
became available, a final raking was undertaken on the previously established
weight variable. Control totals were established using poverty status (five
categories: 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 variables used in the previous
calibrations.
The raking process also incorporated two additional
raking dimensions (sets of control totals) described below in Section 3.2.3.
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3.2.1 MEPS Panel 14 Weight
The person-level weight for MEPS Panel 14 was
developed using the 2009 full year weight for an individual as a "base" weight
for survey participants present in 2009. For key, in-scope members who joined an
RU sometime in 2010 after being out-of-scope in 2009, the initially assigned
person-level weight was the corresponding 2009 family weight. The weighting
process included an adjustment for nonresponse over Rounds 4 and 5 as well as
raking to population control figures for December 2010. These control figures
were derived by scaling back the population totals obtained from the March 2011
CPS to correspond to a national estimate for the civilian noninstitutionalized
population provided by the Census Bureau for December 2010. Variables used in
the establishment of person-level control figures included: census region
(Northeast, Midwest, South, West); MSA status (MSA, non-MSA); race/ethnicity
(Hispanic; black, non-Hispanic; Asian, non-Hispanic; and other); sex; and age. The final weight for key, responding persons who were
not in-scope on December 31, 2010 but were in-scope earlier in the year was the
person weight after the nonresponse adjustment.
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3.2.2 MEPS Panel 15 Weight
The person-level weight for MEPS Panel 15 was
developed using the MEPS Round 1 person-level weight as a "base" weight. For
key, in-scope members 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 2010 portion of Round 3 as well as raking to
the same population control figures for December 2010 used for the MEPS Panel 14
weights. The same five variables employed for Panel 14 raking (census region,
MSA status, race/ethnicity, sex, and age) were used for Panel 15 raking. Again,
the final weight for key, responding persons who were not in-scope on December
31, 2010 but were in-scope earlier in the year was the person weight after the
nonresponse adjustment.
Note that the MEPS Round 1 weights 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 CPS data base of the corresponding year
(i.e., 2009 for Panel 14 and 2010 for Panel 15).
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3.2.3 The Final Weight for 2010
The composite weights of two groups of persons who
were out-of-scope on December 31, 2010 were poststratified. Specifically, the
weights of those who were in-scope sometime during the year, out-of-scope on
December 31, and entered a nursing home during the year were poststratified to a
corresponding control total obtained from the 1996 MEPS Nursing Home Component.
Those who died while in-scope during 2010 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 decedent control totals were developed
for the "65 and older" and "under 65" civilian noninstitutionalized populations.
In developing the final person-level weight for 2010
(PERWT10F), additional raking dimensions were added that reflected the MEPS
2008-09 estimated average annual distributions of office-based visits by age
(under 65, 65 and over) and the proportion of persons age 65 and over with care
from home health agencies. These additional adjustments were included to better
reflect benchmark trends in office-based and home health care utilization. For
each marginal category of the dimensions, the table below shows the ratio of the
weighted number of persons that resulted from including the additional raking
dimensions to that of the corresponding estimate without the additional raking
dimensions.
Ratio of Adjusted to Unadjusted Weights
| Number of Visits |
Nonelderly (AGE10X < 65) |
Elderly (AGE10X ≥ 65) |
| OFFICE-BASED |
| 0 |
0.9169 |
0.8737 |
| 1-5 |
1.0137 |
0.9270 |
| 6-10 |
1.0415 |
1.0581 |
| > 10 |
1.1905 |
1.1058 |
| HOME HEALTH AGENCY |
| 0 |
-- |
0.9882 |
| > 0 |
-- |
1.1564 |
Overall, the weighted population estimate for the
civilian noninstitutionalized population for December 31, 2010 is 304,842,384
(PERWT10F>0 and INSC1231=1). The sum of the person-level weights across all
persons assigned a positive person level weight is 308,573,977.
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3.2.4 Coverage
The target population for MEPS in this file is the
2010 U.S. civilian noninstitutionalized population. However, the MEPS sampled
households are a subsample of the NHIS households interviewed in 2008 (Panel 14)
and 2009 (Panel 15). New households created after the NHIS interviews for the
respective panels and consisting exclusively of persons who entered the target
population after 2008 (Panel 14) or after 2009 (Panel 15) are not covered by
MEPS. Neither are previously out-of-scope persons who join 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 segment of the MEPS target population.
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3.3 Using MEPS Data for Trend Analysis
MEPS began in 1996, and the utility of the survey for
analyzing health care trends expands with each additional year of data. However,
it is important to consider a variety of factors when examining trends over time
using MEPS. Statistical significance tests should be conducted to assess the
likelihood that observed trends may be attributable to sampling variation. The
length of time being analyzed should also be considered. In particular, large
shifts in survey estimates over short periods of time (e.g. from one year to the
next) that are statistically significant should be interpreted with caution,
unless they are attributable to known factors such as changes in public policy,
economic conditions, or MEPS survey methodology. Looking at changes over longer
periods of time can provide a more complete picture of underlying trends.
Analysts of MEPS data may wish to consider using techniques to evaluate, smooth,
or stabilize estimates of trends. Such techniques include comparing pooled time
periods (e.g. 1996-97 versus 2004-05), working with moving averages, or using
modeling techniques with several consecutive years of MEPS data to test the fit
of specified patterns over time. Finally, researchers should be aware of the
impact of multiple comparisons on Type I error (i.e., the chance of declaring an
observed difference to be statistically significant when there is no difference
in the population parameters). Performing numerous statistical significance
tests increases the likelihood of a Type I error.
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4.0 Strategies for Estimation
4.1 Developing Event-Level Estimates
The data in this file can be used to develop national
2010 event level estimates for the U.S. civilian noninstitutionalized population
on emergency room visits as well as expenditures, and sources of payment for
these visits. Estimates of total visits are the sum of the weight variable
(PERWT10F) across relevant event records while estimates of other variables must
be weighted by PERWT10F to be nationally representative. The tables below
contain event-level estimates for selected variables.
Selected Event Level Estimates
Emergency Room Visits
| Estimate of Interest |
Variable
Name |
Estimate
(SE) |
Estimate
Excluding Zero
Payment Events
(SE)* |
Total number of emergency
room visits (in millions) |
PERWT10F |
52.5 (1.66) |
47.3 (1.52) |
Proportion of emergency room
visits with expenditures > 0* |
ERXP10X |
0.902 (0.0067) |
--------------- |
Emergency Room Expenditures
| Estimate of Interest |
Variable
Name |
Estimate
(SE) |
Estimate
Excluding Zero
Payment Events
(SE)* |
| Mean total payments per visit |
ERXP10X |
$920 ($34.8) |
$1,020 ($37.6) |
Mean out-of-pocket payment
per visit |
ERDSF10X
+ERFSF10X |
$93 ($9.0) |
$103 ($9.8) |
Mean proportion of total
expenditures paid by private
insurance per visit |
(ERDPV10X
+ERFPV10X)
/ERXP10X |
--------------- |
0.345 (0.0103) |
* Zero payment events can occur in MEPS for the
following reasons: (1) the stay was covered under a flat fee arrangement (flat
fee payments are included only on the first event covered by the arrangement),
(2) there was no charge for a follow-up stay, (3) the provider was never paid by
an individual, insurance plan, or other source for services provided, or (4)
charges were included in the bill for a subsequent hospital admission (emergency
room events only), or (5) the event was paid for through government or
privately-funded research or clinical trials.
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4.2 Person-Based Estimates for Emergency Room Visits
To enhance analyses of emergency room visits, analysts
may link information about emergency room visits by sample persons in this file
to the annual full year consolidated file (which has data for all MEPS sample
persons), or conversely, link person-level information from the full year
consolidated file to this event level file (see Section 5 below for more
details). Both this file and the full year consolidated file may be used to
derive estimates for persons with emergency room care and annual estimates of
total expenditures. However, if the estimate relates to the entire population,
this file cannot be used to calculate the denominator, as only those persons
with at least one emergency room event are represented on this data file.
Therefore, the full year consolidated file must be used for person-level
analyses that include both persons with and without emergency room care.
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4.3 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 negative 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, and zero expenditures) are described in Section 2.5.6.
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4.4 Variance Estimation (VARPSU, VARSTR)
MEPS has a complex sample design. To obtain estimates
of variability (such as the standard error of sample estimates or corresponding
confidence intervals) for MEPS estimates, analysts need to take into account the
complex sample design of MEPS for both person-level and family-level analyses.
Several methodologies have been developed for estimating standard errors for
surveys with a complex sample design, including the Taylor-series linearization
method, balanced repeated replication, and jackknife replication. Various
software packages provide analysts with the capability of implementing these
methodologies. Replicate weights have not been developed for the MEPS data.
Instead, the variables needed to calculate appropriate standard errors based on
the Taylor-series linearization method are included on this file as well as all
other MEPS public use files. Software packages that permit the use of the
Taylor-series linearization method include SUDAAN, Stata, SAS (version 8.2 and
higher), and SPSS (version 12.0 and higher). For complete information on the
capabilities of each package, analysts should refer to the corresponding
software user documentation.
Using the Taylor-series linearization method, variance
estimation strata and the variance estimation PSUs within these strata must be
specified. The variance strata variable is named VARSTR, while the variance PSU
variable is named VARPSU. Specifying a "with replacement" design in a computer
software package, such as SUDAAN, provides 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), one can expect at least 100 degrees of
freedom for the 2010 full year data associated with the corresponding estimates
of variance and usually substantially more.
Prior to 2002, MEPS variance strata and PSUs were
developed independently from year to year, and the last two characters of the
strata and PSU variable names denoted the year. However, beginning with the 2002
Point-in-Time PUF, the variance strata and PSUs were developed to be compatible
with MEPS data associated with the NHIS sample design used through 2006. Such
data can be pooled and the variance strata and PSU variables provided can be
used without modification for variance estimation purposes for estimates
covering multiple years of data.
As a result of the change in the NHIS sample design in
2006, a new set of variance strata and PSUs have been established for variance
estimation purposes for use with MEPS Panel 12 and subsequent MEPS panels. There
were 165 variance strata associated with both MEPS Panel 14 and Panel 15,
providing a substantial number of degrees of freedom for subgroups as well as
the nation as a whole. Each variance stratum contains either two or three
variance estimation PSUs.
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5.0 Merging/Linking MEPS Data Files
Data from this file can be used alone or in
conjunction with other files for different analytic purposes. This section
summarizes various scenarios for merging/linking MEPS event files. Each MEPS
panel can also be linked back to the previous year’s National Health Interview
Survey public use data files. For information on obtaining MEPS/NHIS link files please see
meps.ahrq.gov/data_stats/more_info_download_data_files.jsp.
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5.1 Linking to the Person-Level File
Merging characteristics of interest from person-level
file (e.g., MEPS 2010 Full Year Consolidated File, or MEPS 2010 Person-Level Use
and Expenditure File) expands the scope of potential estimates. For example, to
estimate the total number of emergency room visits for persons with specific
demographic characteristics (e.g., age, race, sex, and education), population
characteristics from a person-level file need to be merged onto the emergency
room visit file. This procedure is illustrated below. The MEPS 2010 Appendix
File, HC-135I, provides additional detail on how to merge MEPS data files.
- Create data set PERSX by sorting the MEPS 2010 Full Year
Consolidated 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=HCXXX (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;
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5.2 Linking to the Prescribed Medicines File
The RXLK file provides a link from the MEPS event
files to the 2010 Prescribed Medicine Event File. When using RXLK, data
users/analysts should keep in mind that one inpatient stay can link to more than
one prescribed medicine record. Conversely, a prescribed medicine event may link
to more than one inpatient stay 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. For
detailed linking examples, including SAS code, data users/analysts should refer
to the MEPS 2010 Appendix File, HC-135I.
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5.3 Linking to the Medical Conditions File
The CLNK provides a link from MEPS event files to the
2010 Medical Conditions File. When using the CLNK, data users/analysts should
keep in mind that (1) conditions are household-reported, (2) there may be
multiple conditions associated with an emergency room visit and (3) a condition
may link to more than one emergency room visit or any other type of visit. Data
users/analysts should also note that not all emergency room visits link to the
medical conditions file.
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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. (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.
Ezzati-Rice, T.M., Rohde, F., Greenblatt, J., Sample
Design of the Medical Expenditure Panel Survey Household Component, 1998–2007.
Methodology Report No. 22. March 2008. Agency for Healthcare Research and
Quality, Rockville, MD.
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.
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D. Variable-Source Crosswalk
VARIABLE-SOURCE CROSSWALK
FOR MEPS HC-135E: 2010 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 |
| PANEL |
Panel Number |
Constructed |
| MPCDATA |
MPC data flag |
Constructed |
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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 p talk to MD this visit |
ER01 |
| VSTCTGRY |
Best category for care p recv on vst dt |
ER02 |
| VSTRELCN |
This vst related to spec condition |
ER03 |
| LABTEST |
This visit did p have lab tests |
ER05 |
| SONOGRAM |
This visit did p have sonogram or ultrsd |
ER05 |
| XRAYS |
This visit did p have x–rays |
ER05 |
| MAMMOG |
This visit did p have a mammogram |
ER05 |
| MRI |
This visit did p have an MRI/Catscan |
ER05 |
| EKG |
This visit did p have an EKG or ECG |
ER05 |
| EEG |
This visit did p have an EEG |
ER05 |
| RCVVAC |
This visit did p receive a vaccination |
ER05 |
| ANESTH |
This visit did p receive anesthesia |
ER05 |
| THRTSWAB |
This visit did P have a throat swab |
ER05 |
| OTHSVCE |
This visit did p have oth diag tests/exams |
ER05 |
| SURGPROC |
Was surg proc performed on p this visit |
ER06 |
| MEDPRESC |
Any medicine prescribed for p this visit |
ER08 |
| ERICD1X |
3-digit ICD-9-CM condition code |
Edited |
| ERICD2X |
3-digit ICD-9-CM condition code |
Edited |
| ERICD3X |
3-digit ICD-9-CM condition code |
Edited |
| ERPRO1X |
2-digit ICD-9-CM procedure code |
Edited |
| ERPRO2X |
2-digit ICD-9-CM 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 |
| FFBEF10 |
Total # of visits in FF before 2010 |
FF05 |
| FFTOT11 |
Total # of visits in FF after 2010 |
FF10 |
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Imputed Total Expenditure Variables
| Variable |
Description |
Source |
| ERXP10X |
Total exp for event (ERFXP10X + ERDXP10X) |
Constructed |
| ERTC10X |
Total chg for event (ERFTC10X + ERDTC10X) |
Constructed |
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Imputed Facility Expenditure Variables
| Variable |
Description |
Source |
| ERFSF10X |
Facility amt pd, family (Imputed) |
CP Section (Edited) |
| ERFMR10X |
Facility amt pd, Medicare (Imputed) |
CP Section (Edited) |
| ERFMD10X |
Facility amt pd, Medicaid (Imputed) |
CP Section (Edited) |
| ERFPV10X |
Facility amt pd, priv insur (Imputed) |
CP Section (Edited) |
| ERFVA10X |
Facility amt pd, Veterans/CHAMPVA (Imputed) |
CP Section (Edited) |
| ERFTR10X |
Facility amt pd, TRICARE (Imputed) |
CP Section (Edited) |
| ERFOF10X |
Facility amt pd, oth federal (Imputed) |
CP Section (Edited) |
| ERFSL10X |
Facility amt pd, state/local gov (Imputed) |
CP Section (Edited) |
| ERFWC10X |
Facility amt pd, Workers Comp (Imputed) |
CP Section (Edited) |
| ERFOR10X |
Facility amt pd, oth priv (Imputed) |
Constructed |
| ERFOU10X |
Facility amt pd, oth pub (Imputed) |
Constructed |
| ERFOT10X |
Facility amt pd, oth insur (Imputed) |
CP Section (Edited) |
| ERFXP10X |
Facility sum payments ERFSF10X – ERFOT10X |
Constructed |
| ERFTC10X |
Total facility charge (Imputed) |
CP Section (Edited) |
Return To Table Of Contents
Imputed Physician Expenditure Variables
| Variable |
Description |
Source |
| ERDSF10X |
Doctor amount paid, family (Imputed) |
Constructed |
| ERDMR10X |
Doctor amount pd, Medicare (Imputed) |
Constructed |
| ERDMD10X |
Doctor amount paid, Medicaid (Imputed) |
Constructed |
| ERDPV10X |
Doctor amt pd, priv insur (Imputed) |
Constructed |
| ERDVA10X |
Doctor amount paid, Veterans/CHAMPVA (Imputed) |
Constructed |
| ERDTR10X |
Doctor amount pd, TRICARE (Imputed) |
Constructed |
| ERDOF10X |
Doctor amt paid, oth federal (Imputed) |
Constructed |
| ERDSL10X |
Doctor amt pd, state/local gov (Imputed) |
Constructed |
| ERDWC10X |
Doctor amount pd, Workers Comp (Imputed) |
Constructed |
| ERDOR10X |
Doctor amt pd, oth private (Imputed) |
Constructed |
| ERDOU10X |
Doctor amt pd, oth pub (Imputed) |
Constructed |
| ERDOT10X |
Doctor amt pd, oth insur (Imputed) |
Constructed |
| ERDXP10X |
Doctor sum payments ERDSF10X – ERDOT10X |
Constructed |
| ERDTC10X |
Total doctor charge (Imputed) |
Constructed |
| IMPFLAG |
Imputation status |
Constructed |
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Weights
| Variable |
Description |
Source |
| PERWT10F |
Expenditure file person weight, 2010 |
Constructed |
| VARSTR |
Variance estimation stratum, 2010 |
Constructed |
| VARPSU |
Variance estimation PSU, 2010 |
Constructed |
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|
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