MEPS HC-126F: 2009 Outpatient Department Visits (Final)
November 2011
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, 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 Outpatient Visit Event Variables
2.5.3.1 Visit Details (OPDATEYR-VSTRELCN)
2.5.3.2 Treatment, Services, Procedures, and Prescription Medicines (PHYSTH – MEDPRESC)
2.5.4 Conditions and Procedures Codes (OPICD1X-OPICD4X, OPPRO1X-OPPRO2X), and
Clinical Classification Codes (OPCCC1X-OPCCC4X)
2.5.5 Flat Fee Variables (FFEEIDX, FFOPTYPE, FFBEF09, FFTOT10)
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 (FFOPTYPE)
2.5.5.2.3 Counts of Flat Fee Events that Cross Years (FFBEF09, FFTOT10)
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 General Hot-Deck Imputation
2.5.6.2.3 Outpatient Visit Data Editing and Imputation
2.5.6.3 Capitation Imputation
2.5.6.4 Imputation Flag (IMPFLAG)
2.5.6.5 Flat Fee Expenditures
2.5.6.6 Zero Expenditures
2.5.6.7 Discount Adjustment Factor
2.5.6.8 Sources of Payment
2.5.6.9 Imputed Outpatient Expenditure Variables
2.5.6.9.1 Outpatient Facility Expenditure Variables (OPFSF09X-OPFOT09X,
OPFTC09X, OPFXP09X)
2.5.6.9.2 Outpatient Physician Expenditures (OPDSF09X – OPDOT09X, OPDTC09X,
OPDXP09X)
2.5.6.9.3 Total Expenditures and Charges for Outpatient Visits (OPXP09X,
OPTC09X)
2.5.6.10 Rounding
3.0 Sample Weight (PERWT09F)
3.1 Overview
3.2 Details on Person Weight Construction
3.2.1 MEPS Panel 13 Weight
3.2.2 MEPS Panel 14 Weight
3.2.3 The Final Weight for 2009
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 Outpatient Visits
4.3 Variables with Missing Values
4.4 Variance Estimation (VARSTR, VARPSU)
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 2007, 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: www.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 (301-427-1407).
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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 2009 Medical Expenditure Panel Survey (MEPS) Household
(HC) and Medical Provider Components (MPC). Released as an ASCII data file (with
related SAS and SPSS programming statements) and SAS transport file, this public
use file provides detailed information on outpatient visits for a nationally
representative sample of the civilian noninstitutionalized population of the
United States and can be used to make estimates of outpatient utilization and
expenditures for calendar year 2009. The file contains 87 variables and has a
logical record length of 386 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 obtained in the 2009 portion of Round 3 and Rounds 4 and 5 for Panel
13, as well as Rounds 1, 2 and the 2009 portion of Round 3 for Panel 14 (i.e.,
the rounds for the MEPS panels covering calendar year 2009).
Incentive Experiment in Panel 13
With the encouragement of the Office of Management and
Budget (OMB), an experiment was undertaken for MEPS Panel 13 (first fielded in
2008) to evaluate whether and how differential payments to household respondents
might affect survey participation, the level of effort required to obtain
participation, and the quality of the data collected. Each sampled household in
Panel 13 was randomly assigned to one of three different levels of payment--$30,
$50, or $70--with the experiment continuing through the panel’s five rounds
of data collection. Households receiving the $30 payment represent the control
group, since that amount had been offered to all households in the 2007 panel.
To learn more about this experiment, go to the Respondent
Payment Experiment – Results
from Panel 13. Agency for Healthcare Research and Quality, Rockville, MD.
Each record on this event file represents a unique
outpatient event; that is, an outpatient event reported by the household
respondent. Outpatient events reported in Panel 14 Round 3 and known to have
occurred after December 31, 2009 are not included on this file. In
addition to expenditures related to this event, each record contains
household-reported medical conditions and procedures associated with the
outpatient visit.
Annual counts of outpatient 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 this event file can be merged with other
MEPS HC data files, for purposes of appending person characteristics such as
demographic or health insurance characteristics to each outpatient visit record.
This file can also be used to construct summary
variables of expenditures, sources of payment, and related aspects of outpatient
visits. Aggregate annual person-level information on the use of outpatient
departments and other health services is provided on the MEPS 2009 Full Year
Consolidated Data File, where each record represents a MEPS sampled person.
This documentation offers a brief overview of the
types and levels of data provided, and the content and structure of the files
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 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 Outpatient Department Visit
file are available in the Survey Instrument section of the MEPS Web site
at the following address:
www.meps.ahrq.gov.
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2.0 Data File Information
The 2009 Outpatient Department Visit public use data
set consists of one event-level data file. The file contains characteristics
associated with the outpatient event and imputed expenditure data.
The 2009 outpatient public use data set contains
13,133 outpatient event records; of these records, 12,801 are associated with
persons having a positive person-level weight (PERWT09F). This file includes
outpatient event records for all household members who resided in eligible
responding households and for whom at least one outpatient event was reported.
Starting in 2004, new questions were added inquiring whether someone in the
family had a visit to an independent lab or testing facility for x-rays or other
tests. An affirmative answer to these questions would lead to the creation of an
office-based provider event record or an outpatient department event record.
Each record represents one household-reported
outpatient event that occurred during calendar year 2009. Outpatient visits
known to have occurred after December 31, 2009 are not included on this file.
Some household members may have multiple outpatient events and thus will be
represented in multiple records on this file. Other household members may have
had no outpatient events reported and thus will have no records on this file.
These data were collected during the 2009 portion of Round 3, and Rounds 4 and 5
for Panel 13, as well as Rounds 1, 2, and the 2009 portion of Round 3 for Panel
14 of the MEPS HC. The persons represented on this file had to meet either (a)
or (b) below:
- Be classified as a key in-scope person who responded for his or her
entire period of 2009 eligibility (i.e., persons with a positive 2009
full-year person-level weight (PERWT09F > 0)), or
- Be an eligible member of a family all of whose key in-scope members have
a positive person-level weight (PERWT09F > 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 (FAMWT09F >0). Note that FAMIDYR
and FAMWT09F are variables on the 2009 Population Characteristics file.
Persons with no outpatient visit events for 2009 are
not included on this event-level OP file but are represented on the person-level
2009 Full Year Population Characteristics file.
Each outpatient visit record includes the following
information: date of the visit; whether or not the household member saw the
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 2009 MEPS HC person-level data (e.g. Full Year Consolidated or Full
Year Population Characteristics files) using the person identifier, DUPERSID.
Outpatient visit events on this file can also be linked to the MEPS 2009 Medical
Conditions File and to the MEPS 2009 Prescribed Medicines File. Please see
Section 5.0 for details on how to merge MEPS data files.
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2.1 Codebook Structure
For each variable on the Outpatient Department Events
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 outpatient visit identifiers
Outpatient 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:
www.meps.ahrq.gov/survey_comp/survey_questionnaires.jsp).
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2.3 Codebook Format
This 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, 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 so 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;
- FF- Flat Fee section
- CP- Charge Payment section
- OP - Outpatient section
- Variables constructed from multiple questions using complex algorithms
are labeled "Constructed" in the "Source" column; and
- Variables which have been 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 visit
OM - other medical equipment
OB - office-based visit
OP - outpatient visit
DV - dental visit
RX - prescribed medicine
For expenditure variables on the OP file, the third
character indicates whether the expenditure (or amount paid) 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
(09). The eighth character, "X", indicates whether the variable is
edited/imputed.
For example, OPFSF09X is the edited/imputed amount
paid by self or family for the facility portion of the expenditure associated
with an outpatient 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 2009 Full Year Population Characteristics File.
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2.5.1.2 Record Identifiers (EVNTIDX, FFEEIDX)
EVNTIDX uniquely identifies each outpatient event
(i.e., each record on the outpatient file) and is the variable required to link
outpatient events to data files containing details on conditions and/or
prescribed medicines (MEPS 2009 Medical Condition file and MEPS 2009 Prescribed
Medicine file, respectively). For details on linking see Section 5.0 or the MEPS
2009 Appendix File, HC-126I.
FFEEIDX is a constructed variable that uniquely
identifies a flat fee group, that is, all events that were part of a flat fee
payment. For example, if a patient receives stitches during an outpatient visit
and comes back to have the stitches removed ten days later in a follow-up
outpatient visit, both visits are covered under one flat fee dollar amount.
These two events (the initial outpatient visit and the subsequent outpatient
visit) would have the same value for FFEEIDX. A "mixed" flat fee group could
contain both outpatient and office-based visits. Only outpatient and
office-based events are allowed in a mixed bundle. Please note that FFEEIDX
should be used to link up the outpatient and office-based events in order to
determine the full set of events that are part of a flat fee group.
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2.5.1.3 Round Indicator (EVENTRN)
EVENTRN indicates the round in which the outpatient
event was reported. Please note: Rounds 3, 4, and 5 are associated with MEPS
survey data collected from Panel 13. Likewise, Rounds 1, 2, and 3 are associated
with data collected from Panel 14.
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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 13 or Panel 14 for
each person on the file. Panel 13 is the panel that started in 2008, and Panel
14 is the panel that started in 2009.
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2.5.2 MPC Data Indicator (MPCDATA)
MPCDATA is a constructed variable that indicates
whether or not MPC data were collected for the outpatient visit. While all
outpatient events are sampled into the Medical Provider Component, not all
outpatient 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 outpatient facility as well as the cooperation of the outpatient
facility to participate in the survey.
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2.5.3 Outpatient Visit Event Variables
This file contains variables describing outpatient
events reported by respondents in the Outpatient Department section of the MEPS
HC questionnaire. The questionnaire contains specific probes for determining
details about the outpatient visit. These variables have not been edited.
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2.5.3.1 Visit Details (OPDATEYR-VSTRELCN)
When a person reported having had a visit to a
hospital outpatient department or special clinic, the year, month, and day of
the outpatient visit was reported (OPDATEYR, OPDATEMM, OPDATEDD). Also reported
is whether the person actually saw the provider or talked to the provider on the
telephone (SEETLKPV). It also establishes whether the person saw or spoke to a
medical doctor (SEEDOC). If the person did not see a specialty doctor (DRSPLTY),
or, if the person did not see a physician (i.e., medical doctor), the respondent
was asked to identify the type of medical person that was seen (MEDPTYPE). The
type of care the person received (VSTCTGRY), and whether or not the visit or
telephone call was related to a specific condition (VSTRELCN) were also
determined.
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2.5.3.2 Treatment, Services, Procedures,
and Prescription Medicines (PHYSTH-MEDPRESC)
Types of treatment received during the outpatient
visit include physical therapy (PHYSTH), occupational therapy (OCCUPTH), speech
therapy (SPEECHTH), chemotherapy (CHEMOTH), radiation therapy (RADIATTH), kidney
dialysis (KIDNEYD), IV therapy (IVTHER), drug or alcohol treatment (DRUGTRT),
allergy shots (RCVSHOT), psychotherapy/counseling (PSYCHOTH), and shots other
than allergy (OTHSHOT).
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), other diagnostic tests or exams (OTHSVCE), and a throat
swab (THRTSWAB). Minimal editing was done across treatment, services, and
procedures to ensure consistency across "inapplicable," "not ascertained,"
"don’t know," "refused," and "no services received" values.
Whether or not a surgical procedure was performed
during the visit was asked (SURGPROC).
Finally, the questionnaire determined if a medicine
was prescribed for the person during the visit (MEDPRESC). For a repeat visit
event group, if a prescribed medicine is linked to the stem event (MEDPRESC=1),
then the value of MEDPRESC is copied to the leaf events without linking the leaf
events to the prescribed medicine. Beginning in 2009, MEDPRESC=1 was recoded to
-9 for all leaf events.
VAPLACE, a constructed variable that indicates whether
the service was provided at a VA facility, was dropped from this file for
confidentiality purposes beginning in 2008.
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2.5.4 Conditions and Procedures Codes
(OPICD1X-OPICD4X, OPPRO1X-OPPRO2X), and Clinical Classification Codes (OPCCC1X-OPCCC4X)
Information on household-reported medical conditions
and procedures associated with each outpatient visit is provided on this file.
There are up to four condition and CCS codes (OPICD1X-OPICD4X, OPCCC1X-OPCCC4X)
and up to two procedure codes (OPPRO1X-OPPRO2X) listed for each outpatient
visit. In order to obtain complete information on conditions and procedures
associated with an event, the analyst must link to the Medical Conditions File.
Please see Section 5.0 for details on how to link this file to the Medical
Conditions File. The user should note that due to 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 2009 ICD-9-CM codes, including
medical condition and V codes (see Health Care Financing Administration, 1980),
by professional coders. Although codes were verified and error rates did not
exceed 2.5 percent for any coder, 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 (see Cox and
Cohen, 1985; Cox and Iachan, 1987; Edwards, et al, 1994; and Johnson and
Sanchez, 1993). For detailed information on conditions, please refer to the
documentation on the Medical Conditions File.
The ICD-9-CM condition codes were aggregated into
clinically meaningful categories. These categories, included on the file as
OPCCC1X-OPCCC4X, 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 household 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-128 documentation.
The condition and procedure codes (and clinical
classification codes) linked to each outpatient 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 2009 Medical Conditions file in conjunction
with this outpatient visit 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-128) and the Appendix to the Event
Files (HC-126I) 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 2009 MEPS PUFs, these updates
will not be reflected in the 2009 MEPS data.
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2.5.5 Flat Fee Variables (FFEEIDX, FFOPTYPE, FFBEF09, FFTOT10)
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: an obstetrician’s fee covering a normal delivery, as
well as pre- and post-natal care; or a surgeon’s fee covering surgical procedure
along with 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 2009.
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 2009 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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2.5.5.2.2 Flat Fee Type (FFOPTYPE)
FFOPTYPE indicates whether the 2009 outpatient visit
is the "stem" or "leaf" of a flat fee group. A stem (records with FFOPTYPE = 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 FFOPTYPE = 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 outpatient visits that are
not part of a flat fee payment, the FFOPTYPE is set to -1, "INAPPLICABLE."
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2.5.5.2.3 Counts of Flat Fee Events that
Cross Years (FFBEF09, FFTOT10)
As described above, a flat fee payment covers multiple
events and the multiple events could span multiple years. For situations where
the outpatient visit occurred in 2009 as a part of a group of events, and some
of the events occurred before or after 2009, counts of the known events are
provided on the outpatient visit record. Variables indicating events that
occurred before or after 2009 are as follows:
FFBEF09 – total number of pre-2009 events in
the same flat fee group as the 2009 outpatient visit. This count would
not include the 2009 outpatient visit(s).
FFTOT10 – the number of 2010 outpatient visits
expected to be in the same flat fee group as the outpatient visit record
that occurred in 2009.
If there are no 2008 events on the file, FFBEF09 will
be omitted. Likewise, if there are no 2010 events on the file, FFTOT10 will be
omitted. If there are no flat fee data related to the records in this file,
FFEEIDX and FFOPTYPE 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 229 outpatient 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 of these flat fee groups, the
initial visit reported occurred in 2009 but the remaining visits that were part
of this flat fee group occurred in 2010. In this case, the 2009 flat fee group
represented on this file would consist of one event (the stem). The 2010 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 2008 but subsequent visits occurred during 2009. In this case,
the initial visit would not be represented on the file. This 2009 flat fee group
would then only consist of one or more leaf records and no stem. Another reason
for which a flat fee group would not have a stem and at least one leaf record is
that the stem or leaves could have been reported as different event types.
Outpatient and Office-based medical provider visits are the only two event types
allowed in a single flat fee group. The stem may have been reported as an
outpatient department visit and the leaves may have been reported as
office-based medical provider visits.
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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
outpatient services. More specifically, expenditures in MEPS are defined as the
sum of payments for care received for each outpatient 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 paid 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. For details on expenditure definitions,
please reference the following: "Informing American Health Care Policy"
(Monheit, et al., 2000). 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
www.meps.ahrq.gov/data_stats/onsite_datacenter.jsp.
Expenditure data related to outpatient visits are
broken out by facility and separately billing doctor expenditures. This file
contains six categories of expenditure variables per visit: basic hospital
outpatient facility expenses; expenses for doctors who billed separately from
the outpatient facility for any services provided during the outpatient 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 or
performing longitudinal analysis on 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 the Medical Provider Components
(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 outpatient
visits, MPC data were used if available; otherwise, HC data were used. Missing
data for outpatient visits where HC data were not complete and MPC data were not
collected, or MPC data were not complete, were derived 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,
co-payments 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 General Hot-Deck Imputation
A weighted sequential hot-deck procedure was used to
impute for missing expenditures as well as total charge. This procedure uses
survey data from respondents to replace missing data, while taking into account
the persons’ 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.
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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2.5.6.2.3 Outpatient Visit Data Editing and Imputation
Facility expenditures for outpatient 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). (See Section 2.5.5 for more details on flat fee groups).
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 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 hot-deck
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 events among complete events (donors) would not be
represented among incomplete events (recipients).
For office-based and outpatient events, the donor pool
also included events originally reported by providers as paid on a capitated
basis. To obtain the fee-for-service (FFS) equivalent payments for these
capitated events, a "capitation imputation" was implemented (see the next
section). Once imputed with the FFS equivalent payments, these events became
donors for all other incomplete events, particularly for events reported by the
household as services covered under managed care plans.
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.
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2.5.6.3 Capitation Imputation
The imputation process was also used to estimate
expenditures at the event level for events that were paid on a per-month
per-person (capitated) basis. The capitation imputation procedure was designed
as a reasonable approach to complete event-level expenditures for persons in
non-fee for service managed care plans. HMO events reported in the MPC as
covered by capitation arrangements were imputed using similar HMO events paid on
a fee-for-service, with total charge as a key variable. Then this fully
completed set of MPC events was used in the donor pool for the main imputation
process for cases in HMOs. By using this strategy, capitated HMO events were
imputed as if the provider were reimbursed from the HMO on a discounted
fee-for-service basis.
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2.5.6.4 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
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2.5.6.5 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, physician’s expenditures may still
be present. Thus, if the first visit in the flat fee group occurred prior to
2009, all of the events that occurred in 2009 will have zero payments.
Conversely, if the first event in the flat fee group occurred at the end of
2009, the total expenditure for the entire flat fee group will be on that event,
regardless of the number of events it covered after 2009. See Section 2.5.5 for
details on the flat fee variables.
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2.5.6.6 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 visit 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 visit, (3) the provider was never paid
directly for services provided by an individual, insurance plan, or other
source, (4) charges were included in another bill, or (5) event was paid through
government or privately funded research or clinical trials.
The file also contains a small number of events
involving a telephone call rather than a visit to the medical provider (SEETLKPV
= 2). The expenditure variables for telephone calls have a value of -1
"INAPPLICABLE".
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2.5.6.7 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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2.5.6.8 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, excluding TRICARE,
- 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 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 Outpatient 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 Outpatient Facility Expenditure Variables
(OPFSF09X-OPFOT09X, OPFTC09X, OPFXP09X)
Outpatient visit 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 hospital outpatient
visit charge.
OPFSF09X – OPFOT09X are the 12 sources of payment. The
12 sources of payment are: self/family (OPFSF09X), Medicare (OPFMR09X), Medicaid
(OPFMD09X), private insurance (OPFPV09X), Veterans Administration/CHAMPVA
(OPFVA09X), TRICARE (OPFTR09X), other Federal sources (OPFOF09X), State and
Local (non-federal) government sources (OPFSL09X), Workers’ Compensation
(OPFWC09X), other private insurance (OPFOR09X), other public insurance
(OPFOU09X), and other insurance (OPFOT09X). OPFXP09X is the sum of the 12
sources of payment for the Outpatient Facility expenditures, and OPFTC09X is the
total charge. Please note that where an outpatient visit record is linked to a
hospital inpatient stay record, all facility sources of payment variables, as
well as, OPFTC09X have been zeroed out.
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2.5.6.9.2 Outpatient Physician
Expenditures (OPDSF09X – OPDOT09X, OPDTC09X, OPDXP09X)
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 the outpatient facility bill.
For physicians who bill separately (i.e., outside the
outpatient facility bill), a separate data collection effort within the Medical
Provider Component was performed to obtain the 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 outpatient visit could have a radiologist and a pathologist
associated with it. If their services are not included in the outpatient 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. OPDSF09X – OPDOT09X
are the 12 sources of payment, OPDXP09X is the sum of the 12 sources of
payments, and OPDTC09X 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 Outpatient Visits (OPXP09X, OPTC09X)
Data users/analysts interested in total expenditures
should use the variable OPXP09X, which includes both facility and physician
amounts. Those interested in total charges should use the variable OPTC09X,
which includes both facility and physician charges (see Section 2.5.6.1 for an
explanation of the "charge" concept).
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2.5.6.10 Rounding
Expenditure variables have been rounded to the nearest
penny. Person-level expenditure information released on the MEPS 2009
Person-Level and Expenditure File were rounded to the nearest dollar. It should
be noted that using the MEPS 2009 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 expenditure file for that source of payment. This difference is
also an artifact of rounding only. Please see the MEPS 2009 Appendix File,
HC-126I, for details on such rounding differences.
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3.0 Sample Weight (PERWT09F)
3.1 Overview
There is a single full year person-level weight
(PERWT09F) 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 2009. A
key person either was a member of an NHIS household at the time of the NHIS
interview, or became a member of 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 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 PERWT09F was developed in
several stages. Person-level weights for Panel 13 and Panel 14 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,
non-Hispanic with black as sole reported race, non-Hispanic with Asian as sole
reported race, and other); sex; and age. A 2009
composite weight was then formed by multiplying each weight from Panel 13 by the
factor .52 and each weight from Panel 14 by the factor .48. 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.
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3.2.1 MEPS Panel 13 Weight
The person-level weight for MEPS Panel 13 was
developed using the 2008 full year weight for an individual as a "base" weight
for survey participants present in 2008. For key, in-scope RU members who joined
an RU some time in 2009 after being out-of-scope in 2008, the 2008 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 raking to population control figures for December 2009. These control
figures were derived by scaling back the population totals obtained from the
March 2010 CPS to correspond to a national estimate for the civilian
noninstitutionalized population provided by the Census Bureau for December 2009.
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 but non-Hispanic, Asian but non-Hispanic,
and other); sex; and age. Key, responding persons not in-scope on
December 31, 2009 but in-scope earlier in the year retained, as their final
Panel 13 weight, the weight after the nonresponse adjustment.
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3.2.2 MEPS Panel 14 Weight
The person-level weight for MEPS Panel 14 was
developed using the MEPS Round 1 person-level weight as a "base" weight. For
key, in-scope RU 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 2009 portion of Round 3 as well as raking
to the same population control figures for December 2009 used for the MEPS Panel
13 weights. The same five variables employed for Panel 13 raking (census region,
MSA status, race/ethnicity, sex, and age) were used for Panel 14 raking.
Similarly, for Panel 14, key, responding persons not in-scope on December 31,
2009 but in-scope earlier in the year retained, as their final Panel 14 weight,
the 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., 2008 for Panel 13 and 2009 for Panel 14).
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3.2.3 The Final Weight for 2009
The composite weights of two groups of persons who
were out-of-scope on December 31, 2009 were poststratified. Specifically, the
weights of those who were in-scope some time 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 2009 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.
Overall, the weighted population estimate for the
civilian noninstitutionalized population for December 31, 2009 is 302,964,200
(PERWT09F>0 and INSC1231=1). The sum of the person-level weights across all
persons assigned a positive person-level weight is 306,660,588.
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3.2.4 Coverage
The target population for MEPS in this file is the
2009 U.S. civilian noninstitutionalized population. However, the MEPS sampled
households are a subsample of the NHIS households interviewed in 2007 (Panel 13)
and 2008 (Panel 14). New households created after the NHIS interviews for the
respective Panels and consisting exclusively of persons who entered the target
population after 2007 (Panel 13) or after 2008 (Panel 14) 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 may wish to consider using techniques to smooth or stabilize analyses
of trends using MEPS data such as 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. Without making appropriate allowance for multiple
comparisons, undertaking numerous statistical significance tests of trends
increases the likelihood of concluding that a change has taken place when one
has not.
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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
2009 event level estimates for the U.S. civilian noninstitutionalized population
on outpatient visits as well as expenditures, and sources of payment for these
visits. Estimates of total visits are the sum of the weight variable (PERWT09F)
across relevant event records while estimates of other variables must be
weighted by PERWT09F to be nationally representative. The tables below contain
event-level estimates for selected variables.
Selected Event Level Estimates
Outpatient Visits
| Estimate of Interest |
Variable
Name |
Estimate
(SE) |
Estimate
Excluding Zero
Payment Events
(SE)** |
Total number of outpatient
visits (including phone call
events, in millions)* |
PERWT09F |
131.5 (9.44) |
126.7 (9.29) |
Total number of outpatient
visits in person and not by
telephone (SEETLKPV=1,
in millions) |
PERWT09F |
131.2 (9.44) |
126.7 (9.29) |
Total number of in-person
visits to doctor (SEETLKPV=1
& SEEDOC=1, in millions) |
PERWT09F |
53.8 (3.46) |
52.0 (3.35) |
Proportion of outpatient visits
with expenditures > 0** |
OPXP09X |
0.964 (0.0054) |
------------- |
Outpatient Expenditures (SEETLKPV = 1)
| Estimate of Interest |
Variable
Name |
Estimate
(SE) |
Estimate
Excluding Zero
Payment Events
(SE)** |
Mean total payments per visit
(all sources) |
OPXP09X |
$908 ($53.0) |
$941 ($56.2) |
Mean out-of-pocket payment
per visit |
OPDSF09X
+OPFSF09X |
$62 ($5.0) |
$64 ($5.3) |
Mean proportion of total
expenditures paid by private
insurance per visit |
(OPDPV09X
+OPFPV09X)
/OPXP09X |
------------- |
0.379 (0.0238) |
Expenditures: Physician Visits (SEEDOC = 1 & SEETLKPV = 1)
| Estimate of Interest |
Variable
Name |
Estimate
(SE) |
Estimate
Excluding Zero
Payment Events
(SE)** |
Mean total payments
per visit where person
saw medical doctor |
OPXP09X |
$1,490 ($111.0) |
$1,541 ($114.1) |
Mean out-of-pocket payment
per visit where person saw
medical doctor |
OPDSF09X
+OPFSF09X |
$96 ($9.2) |
$99 ($9.4) |
Mean proportion of total
expenditures per visit paid by
private insurance where
person saw medical doctor |
(OPDPV09X
+OPFPV09X)
/OPXP09X |
------------- |
0.372 (0.0238) |
*OPXP09X=-1 (inapplicable) for all phone call events (SEETLKPV=2).
** Zero payment events can occur in MEPS for the
following reasons: (1) the visit 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 visit, (3) the provider was never paid
directly for services provided by an individual, insurance plan, or other
source, (4) charges were included in another bill, or (5) event was paid through
government or privately funded research or clinical trials.
Return To Table Of Contents
4.2 Person-Based Estimates for Outpatient Visits
To enhance analyses of hospital outpatient visits,
analysts may link information about outpatient 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 outpatient 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 outpatient 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 hospital outpatient care.
Return To Table Of Contents
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 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, and zero expenditure)
are described in Section 2.5.6.
Return To Table Of Contents
4.4 Variance Estimation (VARSTR, VARPSU)
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 2009 full year data associated with the corresponding estimates
of variance.
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 2005. 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 13 and Panel 14,
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.
Return To Table Of Contents
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
www.meps.ahrq.gov/data_stats/more_info_download_data_files.jsp.
Return To Table Of Contents
5.1 Linking to the Person-Level File
Merging characteristics of interest from other MEPS
files (e.g., MEPS 2009 Full Year Consolidated File) expands the scope of
potential estimates. For example, to estimate the total number of outpatient
visits for persons with specific characteristics (e.g., age, race, sex, and
education), population characteristics from a person-level file need to be
merged onto the outpatient visit file. This procedure is illustrated below. The
MEPS 2009 Appendix File, HC-126I, provides additional detail on how to merge
MEPS data files.
- Create data set PERSX by sorting the Full Year Consolidated file by the
person identifier, DUPERSID. Keep only variables to be merged onto the
outpatient visit file and DUPERSID.
- Create data set OPAT by sorting the outpatient visit file by person
identifier, DUPERSID.
- Create final data set NEWOPAT by merging these two files by DUPERSID,
keeping only records on the outpatient 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=OPAT;
BY DUPERSID;
RUN;
DATA NEWOPAT;
MERGE OPAT(IN=A) PERSX(IN=B);
BY DUPERSID;
IF A;
RUN;
Return To Table Of Contents
5.2 Linking to the Prescribed Medicines File
The RXLK file provides a link from the MEPS event
files to the Prescribed Medicine Event File. When using RXLK, data
users/analysts should keep in mind that one outpatient event can link to more
than one prescribed medicine record. Conversely, a prescribed medicine event may
link to more than one outpatient event 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 2009 Appendix File, HC-126I.
Return To Table Of Contents
5.3 Linking to the Medical Conditions File
The CLNK provides a link from MEPS event files to the
2009 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 outpatient visit, and (3) a condition may
link to more than one outpatient visit or any other type of visit. Users should
also note that not all outpatient 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 and
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 the American
Statistical Association 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. (2000). 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-126F: 2009 OUTPATIENT DEPARTMENT 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 |
| PANEL |
Panel number |
Constructed |
| FFEEIDX |
Flat Fee ID |
CAPI derived |
| MPCDATA |
MPC data flag |
Constructed |
Return To Table Of Contents
Outpatient Department Visit Variables
| Variable |
Description |
Source |
| OPDATEYR |
Event date – year |
CAPI derived |
| OPDATEMM |
Event date – month |
CAPI derived |
| OPDATEDD |
Event date – day |
CAPI derived |
| SEETLKPV |
Did person visit provider in person or telephone |
OP02 |
| SEEDOC |
Did person talk to MD this visit/phone call |
OP04 |
| DRSPLTY |
OPAT doctor specialty |
OP04A |
| MEDPTYPE |
Type of medical person talked to on visit date |
OP05 |
| VSTCTGRY |
Best category for care person received on visit date |
OP07 |
| VSTRELCN |
This visit/phone call related to spec condition |
OP08 |
| PHYSTH |
This visit did person have physical therapy |
OP10 |
| OCCUPTH |
This visit did person have occupational therapy |
OP10 |
| SPEECHTH |
This visit did person have speech therapy |
OP10 |
| CHEMOTH |
This visit did person have chemotherapy |
OP10 |
| RADIATTH |
This visit did person have radiation therapy |
OP10 |
| KIDNEYD |
This visit did person have kidney dialysis |
OP10 |
| IVTHER |
This visit did person have IV therapy |
OP10 |
| DRUGTRT |
This visit did person have treatment for drug/alcohol |
OP10 |
| RCVSHOT |
This visit did person receive an allergy shot |
OP10 |
| PSYCHOTH |
This visit did person have psychotherapy/counseling |
OP10 |
| OTHSHOT |
This visit did P have other shot |
OP10 |
| LABTEST |
This visit did person have lab tests |
OP11 |
| SONOGRAM |
This visit did person have sonogram or ultrasound |
OP11 |
| XRAYS |
This visit did person have x-rays |
OP11 |
| MAMMOG |
This visit did person have a mammogram |
OP11 |
| MRI |
This visit did person have an MRI/Catscan |
OP11 |
| EKG |
This visit did person have an EKG or ECG |
OP11 |
| EEG |
This visit did person have an EEG |
OP11 |
| RCVVAC |
This visit did person receive a vaccination |
OP11 |
| ANESTH |
This visit did person receive anesthesia |
OP11 |
| OTHSVCE |
This visit did person have other diagnostic tests or exams |
OP11 |
| THRTSWAB |
This visit did P have a throat swab |
OP11 |
| SURGPROC |
Was surgical procedure performed on person this visit |
OP12 |
| MEDPRESC |
Any medicine prescribed for person during visit |
OP14 |
| OPICD1X |
3-digit ICD-9-CM condition code |
Edited |
| OPICD2X |
3-digit ICD-9-CM condition code |
Edited |
| OPICD3X |
3-digit ICD-9-CM condition code |
Edited |
| OPICD4X |
3-digit ICD-9-CM condition code |
Edited |
| OPPRO1X |
2-digit ICD-9-CM procedure code |
Edited |
| OPPRO2X |
2-digit ICD-9-CM procedure code |
Edited |
| OPCCC1X |
Modified Clinical Classification Code |
Constructed/ Edited |
| OPCCC2X |
Modified Clinical Classification Code |
Constructed/ Edited |
| OPCCC3X |
Modified Clinical Classification Code |
Constructed/ Edited |
| OPCCC4X |
Modified Clinical Classification Code |
Constructed/ Edited |
Return To Table Of Contents
Flat Fee Variables
| Variable |
Description |
Source |
| FFOPTYPE |
Flat fee bundle |
Constructed |
| FFBEF09 |
Total # of visits in FF before 2009 |
FF05 |
| FFTOT10 |
Total # of visits in FF after 2009 |
FF10 |
Return To Table Of Contents
Imputed Expenditure Variables
| Variable |
Description |
Source |
| OPXP09X |
Total expenditure for event
(OPFXP09X+OPDXP09X) |
Constructed |
| OPTC09X |
Total charge for event (OPFTC09X+OPDTC09X) |
Constructed |
| OPFSF09X |
Facility amount paid, self/family (Imputed) |
CP Section (Edited) |
| OPFMR09X |
Facility amount paid, Medicare (Imputed) |
CP Section (Edited) |
| OPFMD09X |
Facility amount paid, Medicaid (Imputed) |
CP Section (Edited) |
| OPFPV09X |
Facility amount paid, private insurance (Imputed) |
CP Section (Edited) |
| OPFVA09X |
Facility amount paid, Veterans/CHAMPVA (Imputed) |
CP Section (Edited) |
| OPFTR09X |
Facility amount paid, TRICARE (Imputed) |
CP Section (Edited) |
| OPFOF09X |
Facility amount paid, other federal (Imputed) |
CP Section (Edited) |
| OPFSL09X |
Facility amount paid, state & local government (Imputed) |
CP Section (Edited) |
| OPFWC09X |
Facility amount paid, workers’ compensation (Imputed) |
CP Section (Edited) |
| OPFOR09X |
Facility amount paid, other private insurance (Imputed) |
Constructed |
| OPFOU09X |
Facility amount paid, other public insurance (Imputed) |
Constructed |
| OPFOT09X |
Facility amount paid, other insurance (Imputed) |
CP Section (Edited) |
| OPFXP09X |
Facility sum payments OPFSF09X -OPFOT09X |
Constructed |
| OPFTC09X |
Total facility charge (Imputed) |
CP Section (Edited) |
| OPDSF09X |
Doctor amount paid, self/family (Imputed) |
Constructed |
| OPDMR09X |
Doctor amount paid, Medicare (Imputed) |
Constructed |
| OPDMD09X |
Doctor amount paid, Medicaid (Imputed) |
Constructed |
| OPDPV09X |
Doctor amount paid, private insurance (Imputed) |
Constructed |
| OPDVA09X |
Doctor amount paid, Veterans/CHAMPVA (Imputed) |
Constructed |
| OPDTR09X |
Doctor amount paid, TRICARE (Imputed) |
Constructed |
| OPDOF09X |
Doctor amount paid, other federal (Imputed) |
Constructed |
| OPDSL09X |
Doctor amount paid, state & local government (Imputed) |
Constructed |
| OPDWC09X |
Doctor amount paid, workers’ compensation (Imputed) |
Constructed |
| OPDOR09X |
Doctor amount paid, other private insurance (Imputed) |
Constructed |
| OPDOU09X |
Doctor amount paid, other public insurance (Imputed) |
Constructed |
| OPDOT09X |
Doctor amount paid, other insurance (Imputed) |
Constructed |
| OPDXP09X |
Doctor sum payments OPDSF09X -OPDOT09X |
Constructed |
| OPDTC09X |
Total doctor charge (Imputed) |
Constructed |
| IMPFLAG |
Imputation status |
Constructed |
Return To Table Of Contents
Weights
| Variable |
Description |
Source |
| PERWT09F |
Expenditure file person weight, 2009 |
Constructed |
| VARSTR |
Variance estimation stratum, 2009 |
Constructed |
| VARPSU |
Variance estimation PSU, 2009 |
Constructed |
Return To Table Of Contents
|
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