| MEPS HC-178F: 2015 Outpatient Department VisitsJune 2017 Agency for Healthcare Research and QualityCenter for Financing, Access, and Cost Trends
 5600 Fishers Lane
 Rockville, MD 20857
 (301) 427-1406
 Table of Contents A. Data Use AgreementB. 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 Services, Procedures, and Prescription Medicines (LABTEST-MEDPRESC)
 2.5.4 Clinical Classification Codes (OPCCC1X-OPCCC4X)
 2.5.5 Flat Fee Variables (FFEEIDX, FFOPTYPE, FFBEF15, FFTOT16)
 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 (FFBEF15, FFTOT16)
 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 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 (OPFSF15X-OPFOT15X, OPFXP15X, OPFTC15X)
 2.5.6.9.2 Outpatient Physician Expenditures (OPDSF15X – OPDOT15X, OPDXP15X, OPDTC15X)
 2.5.6.9.3 Total Expenditures and Charges for Outpatient Visits (OPXP15X, OPTC15X)
 2.5.6.10 Rounding
 3.0 Sample Weight (PERWT15F)
 3.1 Overview
 3.2 Details on Person Weight Construction
 3.2.1 MEPS Panel 19 Weight Development Process
 3.2.2 MEPS Panel 20 Weight Development Process
 3.2.3 The Final Weight for 2015
 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
 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; andNo 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.  Return To Table Of Contents 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. The linkage of the 
MEPS to the previous year’s NHIS provides additional data for longitudinal 
analytic purposes. Return To Table Of Contents 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 cannot 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. Return To Table Of Contents 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, 
5600 Fishers Lane, Rockville, MD 20857 (301-427-1406). Return To Table Of Contents This documentation describes one in a series of public 
use event files from the 2015 Medical Expenditure Panel Survey (MEPS) Household 
(HC) and Medical Provider Components (MPC). Released as an ASCII data file (with 
related SAS, SPSS, and Stata 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 2015. The file contains 69 variables and has 
a logical record length of 346 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 2015 portion of Round 3 and Rounds 4 and 5 for Panel 
19, as well as Rounds 1, 2 and the 2015 portion of Round 3 for Panel 20 (i.e., 
the rounds for the MEPS panels covering calendar year 2015). 
 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 20 Round 3 and known to have 
occurred after December 31, 2015 are not included on this file. In 
addition to expenditures related to this event, each record contains 
household-reported medical conditions 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 2015 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 InformationSample WeightStrategies for EstimationMerging/Linking MEPS Data FilesReferencesVariable - Source Crosswalk Any variables not found on this file but released on 
previous years’ files may have been 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 Visits 
file are available in the Survey Questionnaires section of the MEPS Web 
site at the following address: meps.ahrq.gov. Return To Table Of Contents The 2015 Outpatient Department Visits public use data 
set consists of one event-level data file. The file contains characteristics 
associated with the outpatient (OP) event and imputed expenditure data.  The 2015 outpatient public use data set contains 
14,178 outpatient event records; of these records, 13,758 are associated with 
persons having a positive person-level weight (PERWT15F). 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. 
Questions inquired 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 leads 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 2015. Outpatient visits 
known to have occurred after December 31, 2015 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 2015 portion of Round 3, and Rounds 4 and 5 
for Panel 19, as well as Rounds 1, 2, and the 2015 portion of Round 3 for Panel 
20 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 2015 eligibility (i.e., persons with a 
				positive 2015 full-year person-level weight (PERWT15F > 0)), or
 
Be an eligible member of a family all of whose key in-scope 
				members have a positive person-level weight (PERWT15F > 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 (FAMWT15F>0). Note that FAMIDYR and FAMWT15F 
				are variables on the 2015 Full Year Consolidated Data File. Persons with no outpatient visit events for 2015 are 
not included on this event-level OP file but are represented on the person-level 
2015 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 2015 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 2015 Medical 
Conditions File and to the MEPS 2015 Prescribed Medicines File. Please see 
Section 5.0 for details on how to merge MEPS data files.  Return To Table Of Contents For most variables on the Outpatient Department events 
file, both weighted and unweighted frequencies are provided in the accompanying 
codebook. The exceptions to this are weight variables and variance estimation 
variables. Only unweighted frequencies of these variables are included in the 
accompanying codebook file. See the Weights Variables list in Section D, 
Variable-Source Crosswalk. The codebook and data file sequence list variables in 
the following order: 
Unique person identifiersUnique outpatient visit identifiersOutpatient characteristic variablesClinical Classification Software (CCS) codesImputed expenditure variablesWeight and variance estimation variables Note that the person identifier is unique within this data year.  Return To Table Of Contents 
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). Return To Table Of Contents 
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 of 40 characters) |  
								| Format | Number of bytes |  
								| Type | Type of data: numeric (indicated by NUM) or character (indicated by CHAR) |  
								| Start | Beginning column position of variable in record |  
								| End | Ending column position of variable in record |  Return To Table Of Contents In general, variable names reflect the content of the 
variable, with an eight-character limitation. All imputed/edited variables end 
with an “X”. Return To Table Of Contents 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 sectionCP- Charge Payment sectionOP - Outpatient 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.  Return To Table Of Contents 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 
(15). The eighth character, “X”, indicates whether the variable is 
edited/imputed. For example, OPFSF15X is the edited/imputed amount 
paid by self or family for the facility portion of the expenditure associated 
with an outpatient visit.  Return To Table Of Contents 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 2015 Full Year Population Characteristics File. Return To Table Of Contents 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 2015 Medical Condition file and MEPS 2015 Prescribed 
Medicines file, respectively). For details on linking see Section 5.0 or the 
MEPS 2015 Appendix File, HC-178I. 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. Return To Table Of Contents 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 19. Likewise, Rounds 1, 2, and 3 are associated 
with data collected from Panel 20. Return To Table Of Contents PANEL is a constructed variable used to specify the 
panel number for the person. PANEL will indicate either Panel 19 or Panel 20 for 
each person on the file. Panel 19 is the panel that started in 2014, and Panel 
20 is the panel that started in 2015. Return To Table Of Contents 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. Return To Table Of Contents 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. Return To Table Of Contents When a person reported having had a visit to a 
hospital outpatient department or special clinic, the year and month of the 
outpatient visit was reported (OPDATEYR and OPDATEMM). 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. Note that response categories with small frequencies may have been 
recoded to other categories for confidentiality reasons. Return To Table Of Contents 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), a throat swab (THRTSWAB), and other diagnostic tests or 
exams (OTHSVCE). 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. Return To Table Of Contents Information on household-reported medical conditions 
associated with each outpatient visit is provided on this file. There are up to 
four CCS codes (OPCCC1X-OPCCC4X) listed for each outpatient visit, as shown in 
the crosswalk of this document. The file includes the number of CCS codes 
reported in the data year, which may be fewer than the maximum four CCS codes. 
Because the maximum number of conditions associated with an event can change 
from year to year, the number of reported CCS codes also can change from year to 
year. Starting with the 2013 file, the ICD-9-CM condition and procedure codes 
variables are omitted. In order to obtain complete information on conditions 
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 reported by the Household 
Component respondent were recorded by the interviewer as verbatim text, which 
were then coded to fully-specified 2015 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 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.  The 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 2015 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 (HC-180) document and the Appendix to the Event 
Files (HC-178I) 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 2015 MEPS PUFs, these updates 
will not be reflected in the 2015 MEPS data. Return To Table Of Contents 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 2015. 
By definition a flat fee group can span multiple years. Furthermore, a single 
person can have multiple flat fee groups. Return To Table Of Contents 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 2015 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.  Return To Table Of Contents FFOPTYPE indicates whether the 2015 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.” Return To Table Of Contents 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 2015 as a part of a group of events, and some 
of the events occurred before or after 2015, counts of the known events are 
provided on the outpatient visit record. Variables indicating events that 
occurred before or after 2015 are as follows: FFBEF15 – total number of pre-2015 events in the same 
flat fee group as the 2015 outpatient visit. This count would not include the 2015 outpatient visit(s).  FFTOT16 – the number of 2016 outpatient visits 
expected to be in the same flat fee group as the outpatient visit record that occurred in 2015.  Return To Table Of Contents There are 245 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 2015 but the remaining visits that were part 
of this flat fee group occurred in 2016. In this case, the 2015 flat fee group 
represented on this file would consist of one event (the stem). The 2016 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 2014 but subsequent visits occurred during 2015. In this case, 
the initial visit would not be represented on the file. This 2015 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. Please note that the crosswalk in this 
document lists all possible flat fee variables. Return To Table Of Contents 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. Currently, 
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., 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/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, please 
refer to Section 3.3 for more information.  Return To Table Of Contents 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. Return To Table Of Contents 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.  Return To Table Of Contents 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. The imputations for the flat 
fee events were carried out separately from the simple events. 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. Return To Table Of Contents 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 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). (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 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 outpatient events, the donor pool was restricted to events with complete 
expenditures from the MPC.  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.  Return To Table Of Contents 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.  Return To Table Of Contents 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 OB 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 Return To Table Of Contents 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 
2015, all of the events that occurred in 2015 will have zero payments. 
Conversely, if the first event in the flat fee group occurred at the end of 
2015, the total expenditure for the entire flat fee group will be on that event, 
regardless of the number of events it covered after 2015. See Section 2.5.5 for 
details on the flat fee variables. Return To Table Of Contents 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) the charges were included in another bill, or (5) the 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”. Return To Table Of Contents 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.  Return To Table Of Contents 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, andOther 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, andOther 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. Return To Table Of Contents This file contains two sets of imputed expenditure 
variables: facility expenditures and physician expenditures.  Return To Table Of Contents 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.  OPFSF15X – OPFOT15X are the 12 sources of payment. The 
12 sources of payment are: self/family (OPFSF15X), Medicare (OPFMR15X), Medicaid 
(OPFMD15X), private insurance (OPFPV15X), Veterans Administration/CHAMPVA 
(OPFVA15X), TRICARE (OPFTR15X), other federal sources (OPFOF15X), state and 
local (non-federal) government sources (OPFSL15X), Workers’ Compensation 
(OPFWC15X), other private insurance (OPFOR15X), other public insurance 
(OPFOU15X), and other insurance (OPFOT15X). OPFXP15X is the sum of the 12 
sources of payment for the outpatient facility expenditures, and OPFTC15X 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 OPFTC15X have been zeroed out.  Return To Table Of Contents 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. OPDSF15X – OPDOT15X 
are the 12 sources of payment, OPDXP15X is the sum of the 12 sources of 
payments, and OPDTC15X 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).  Return To Table Of Contents Data users/analysts interested in total expenditures 
should use the variable OPXP15X, which includes both facility and physician 
amounts. Those interested in total charges should use the variable OPTC15X, 
which includes both facility and physician charges (see Section 2.5.6.1 for an 
explanation of the “charge” concept). Return To Table Of Contents Expenditure variables have been rounded to the nearest 
penny. Person-level expenditure information released on the MEPS 2015 
Person-Level Use and Expenditure File were rounded to the nearest dollar. 
It should be noted that using the MEPS 2015 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.  Return To Table Of Contents There is a single full year person-level weight 
(PERWT15F) 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 2015. 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. Return To Table Of Contents The person-level weight PERWT15F was developed in 
several stages. Person-level weights for Panel 19 and Panel 20 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 for those in-scope at the end of the calendar year 
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 2015 composite weight was then formed by multiplying 
each weight from Panel 19 by the factor .460 and each weight from Panel 20 by 
the factor .540. 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 raked to the same set of CPS-based 
control totals. When the 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 other five variables previously used in the 
weight calibration. Return To Table Of Contents The person-level weight for MEPS Panel 19 was 
developed using the 2014 full year weight for an individual as a “base” weight 
for survey participants present in 2014. For key, in-scope members who joined an 
RU some time in 2015 after being out-of-scope in 2014, the initially assigned 
person-level weight was the corresponding 2014 family weight. The weighting 
process included an adjustment for person-level nonresponse over Rounds 4 and 5 
as well as raking to population control totals for December 2015 for key, 
responding persons in-scope on December 31, 2015. These control figures were 
derived by scaling back the population distribution obtained from the March 2016 
CPS to reflect the December 31, 2015 estimated population total (estimated based 
on Census projections for January 1, 2016). Variables used for person-level 
raking 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. (Poverty status is not included in this version 
of the MEPS full year database because of the time required to process the 
income data collected and then assign persons to a poverty status category). The 
final weight for key, responding persons who were not in-scope on December 31, 
2015 but were in-scope earlier in the year was the person weight after the 
nonresponse adjustment. Return To Table Of Contents The person-level weight for MEPS Panel 20 was 
developed using the 2015 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 the remaining data collection rounds in 2015 as well as 
raking to the same population control figures for December 2015 used for the 
MEPS Panel 19 weights for key, responding persons in-scope on December 31, 2015. 
The same five variables employed for Panel 19 raking (census region, MSA status, 
race/ethnicity, sex, and age) were used for Panel 20 raking. Again, the final 
weight for key, responding persons who were not in-scope on December 31, 2015 
but were in-scope earlier in the year was the person weight after the 
nonresponse adjustment. Note that the MEPS Round 1 weights for both panels 
incorporated the following components: a weight reflecting the original 
household probability of selection for the NHIS and an adjustment for NHIS 
nonresponse; a factor representing the proportion of the 16 NHIS panel-quarter 
combinations eligible for MEPS; the oversampling of certain subgroups for MEPS 
among the NHIS household respondents eligible for MEPS; ratio-adjustment to NHIS-based 
national population estimates at the household (occupied DU) level; adjustment 
for nonresponse at the DU level for Round 1; and poststratification to U.S. 
civilian noninstitutionalized population estimates at the family and person 
level obtained from the corresponding March CPS databases. Return To Table Of Contents The final raking of those in-scope at the end of the 
year has been described above. In addition, the composite weights of two groups 
of persons who were out-of-scope on December 31, 2015 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. The weights of persons who died while in-scope during 
2015 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 decedent populations.  Overall, the weighted population estimate for the 
civilian noninstitutionalized population for December 31, 2015 is 317,629,239 
(PERWT15F>0 and INSC1231 = 1). The sum of the person-level weights across all 
persons assigned a positive person-level weight is 321,423,251.  Return To Table Of Contents The target population for MEPS in this file is the 
2015 U.S. civilian noninstitutionalized population. However, the MEPS sampled 
households are a subsample of the NHIS households interviewed in 2013 (Panel 19) 
and 2014 (Panel 20). New households created after the NHIS interviews for the 
respective panels and consisting exclusively of persons who entered the target 
population after 2013 (Panel 19) or after 2014 (Panel 20) 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. Return To Table Of Contents 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.  With respect to methodological considerations, in 2013 
MEPS introduced an effort to obtain more complete information about health care 
utilization from MEPS respondents with full implementation in 2014. This effort 
likely resulted in improved data quality and a reduction in underreporting in FY 
2014, and could have some modest impact on analyses involving trends in 
utilization across years. There are also statistical factors to consider in 
interpreting trend analyses. 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 evaluate, smooth, or stabilize analyses of trends 
using MEPS data such as comparing pooled time periods (e.g. 1996-97 versus 
2011-12), 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. Return To Table Of Contents The data in this file can be used to develop national 
2015 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 (PERWT15F) 
across relevant event records while estimates of other variables must be 
weighted by PERWT15F 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)* | PERWT15F | 157.8 (8.52) | 151.4 (8.27) |  
        | Total number of 
								outpatient visits in person and not by telephone 
								(SEETLKPV=1, in millions) | PERWT15F | 156.9 (8.50) | 151.4 (8.27) |  
        | Total number of 
								in-person visits to doctor (SEETLKPV=1 & SEEDOC=1, 
								in millions) | PERWT15F | 66.7 (3.66) | 64.4 (3.59) |  
        | Proportion of 
								outpatient visits with expenditures > 0** | OPXP15X | 0.960 (0.0046) | -- |  
 
 Outpatient Expenditures (SEETLKPV = 1)
 
 
        | Estimate of Interest | Variable Name | Estimate (SE) | Estimate Excluding Zero Payment Events (SE)**
 |  
        | Mean total payments 
								per visit (all sources) | OPXP15X | $863 ($42.8) | $894 ($44.1) |  
        | Mean out-of-pocket 
								payment per visit | OPDSF15X +OPFSF15X | $62 ($5.1) | $65 ($5.3) |  
        | Mean proportion of 
								total expenditures paid by private insurance per 
								visit | (OPDPV15X+OPFPV15X) 
								/OPXP15X | -- | 0.359 (0.0163) |  
 
 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 | OPXP15X | $1,362 ($69.2) | $1,410 ($72.1) |  
        | Mean out-of-pocket 
								payment per visit where person saw medical 
								doctor | OPDSF15X +OPFSF15X | $105 ($9.9) | $109 ($10.3) |  
        | Mean proportion of 
								total expenditures per visit paid by private 
								insurance where person saw medical doctor | (OPDPV15X+OPFPV15X)/OPXP15X | -- | 0.370 (0.0158) |  *OPXP15X = -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) the charges were included in another bill, or (5) the event was paid 
through government or privately funded research or clinical trials. Return To Table Of Contents 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 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 software package 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. Return To Table Of Contents The MEPS is based on 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 variables VARSTR and VARPSU on this MEPS data file serve to 
identify the sampling strata and primary sampling units required by the variance 
estimation programs. Specifying a “with replacement” design in one of the 
previously mentioned computer software packages will provide estimated 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 
number available. For variables of interest distributed throughout the country 
(and thus the MEPS sample PSUs), one can generally expect to have at least 100 
degrees of freedom associated with the estimated standard errors for national 
estimates based on this MEPS database. 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 all future PUFs until the NHIS design changed. Thus, when pooling data 
across years 2002 through the Panel 11 component of the 2007 files, the variance 
strata and PSU variables provided can be used without modification for variance 
estimation purposes for estimates covering multiple years of data. There were 
203 variance estimation strata, each stratum with either two or three variance 
estimation PSUs.  From Panel 12 of the 2007 files, a new set of variance 
strata and PSUs were developed because of the introduction of a new NHIS design. 
There are 165 variance strata with either two or three variance estimation PSUs 
per stratum, starting from Panel 12. Therefore, there are a total of 368 
(203+165) variance strata in the 2007 Full Year file as it consists of two 
panels that were selected under two independent NHIS sample designs. Since both 
MEPS panels in the Full Year 2008 file and beyond are based on the new NHIS 
design, there are only 165 variance strata. These variance strata (VARSTR 
values) have been numbered from 1001 to 1165 so that they can be readily 
distinguished from those developed under the former NHIS sample design in the 
event that data are pooled for several years. If analyses call for pooling MEPS data across several 
years, in order to ensure that variance strata are identified appropriately for 
variance estimation purposes, one can proceed as follows: 
				When pooling any year from 2002 or later, one can use the 
				variance strata numbering as is.
 
When pooling any year from 1996 to 2001 with any year from 
				2002 or later, use the H36 file.
 
A new H36 file will be constructed in the future to allow 
				pooling of 2007 and later years with 1996 to 2006. Return To Table Of Contents 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. Return To Table Of Contents Merging characteristics of interest from other MEPS 
files (e.g., MEPS 2015 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 2015 Appendix File, HC-178I, provides additional details 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 RACEV1X EDUYRDG EDRECODE EDUCYR HIDEG) 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 The prescribed medicines-event link (RXLK) file 
provides a link from the MEPS event files to the Prescribed Medicines Event 
File. When using the 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 2015 Appendix File, 
HC-178I. Return To Table Of Contents The condition-event link (CLNK) file provides a link 
from MEPS event files to the 2015 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 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. (1999). Jossey-Bass 
Inc, San Francisco. Shah, B.V., Barnwell, B.G., Bieler, G.S., Boyle, K.E., 
Folsom, R.E., Lavange, L., Wheeless, S.C., and Williams, R. (1996). Technical 
Manual: Statistical Methods and Algorithms Used in SUDAAN Release 7.0, 
Research Triangle Park, NC: Research Triangle Institute. Return To Table Of Contents VARIABLE-SOURCE CROSSWALK
 FOR MEPS HC-178F: 2015 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 |  
	  | 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 |  
	  | 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 |  
	  | THRTSWAB | This visit did P have a throat swab | OP11 |  
	  | OTHSVCE | This visit did person have other diagnostic tests or exams | OP11 |  
	  | SURGPROC | Was surgical procedure performed on person this visit | OP12 |  
	  | MEDPRESC | Any medicine prescribed for person during visit | OP14 |  
	  | 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 |  
      | FFBEF15 | Total # of visits in FF before 2015 | FF05 |  
      | FFTOT16 | Total # of visits in FF after 2015 | FF10 |  Return To Table Of Contents 
Imputed Expenditure Variables
 
 
          | Variable | Description | Source |  
      | OPXP15X | Total expenditure for event (OPFXP15X+OPDXP15X) | Constructed |  
      | OPTC15X | Total charge for event (OPFTC15X+OPDTC15X) | Constructed |  
      | OPFSF15X | Facility amount paid, self/family (Imputed) | CP Section (Edited) |  
      | OPFMR15X | Facility amount paid, Medicare (Imputed) | CP Section (Edited) |  
      | OPFMD15X | Facility amount paid, Medicaid (Imputed) | CP Section (Edited) |  
      | OPFPV15X | Facility amount paid, private insurance (Imputed) | CP Section (Edited) |  
      | OPFVA15X | Facility amount paid, Veterans/CHAMPVA (Imputed) | CP Section (Edited) |  
      | OPFTR15X | Facility amount paid, TRICARE (Imputed) | CP Section (Edited) |  
      | OPFOF15X | Facility amount paid, other federal (Imputed) | CP Section (Edited) |  
      | OPFSL15X | Facility amount paid, state & local government (Imputed) | CP Section (Edited) |  
      | OPFWC15X | Facility amount paid, workers’ compensation (Imputed) | CP Section (Edited) |  
      | OPFOR15X | Facility amount paid, other private insurance (Imputed) | Constructed |  
      | OPFOU15X | Facility amount paid, other public insurance (Imputed) | Constructed |  
      | OPFOT15X | Facility amount paid, other insurance (Imputed) | CP Section (Edited) |  
      | OPFXP15X | Facility sum payments OPFSF15X –OPFOT15X | Constructed |  
      | OPFTC15X | Total facility charge (Imputed) | CP Section (Edited) |  
      | OPDSF15X | Doctor amount paid, self/family (Imputed) | Constructed |  
      | OPDMR15X | Doctor amount paid, Medicare (Imputed) | Constructed |  
      | OPDMD15X | Doctor amount paid, Medicaid (Imputed) | Constructed |  
      | OPDPV15X | Doctor amount paid, private insurance (Imputed) | Constructed |  
      | OPDVA15X | Doctor amount paid, Veterans/CHAMPVA (Imputed) | Constructed |  
      | OPDTR15X | Doctor amount paid, TRICARE (Imputed) | Constructed |  
      | OPDOF15X | Doctor amount paid, other federal (Imputed) | Constructed |  
      | OPDSL15X | Doctor amount paid, state & local government (Imputed) | Constructed |  
      | OPDWC15X | Doctor amount paid, workers’ compensation (Imputed) | Constructed |  
      | OPDOR15X | Doctor amount paid, other private insurance (Imputed) | Constructed |  
      | OPDOU15X | Doctor amount paid, other public insurance (Imputed) | Constructed |  
      | OPDOT15X | Doctor amount paid, other insurance (Imputed) | Constructed |  
      | OPDXP15X | Doctor sum payments OPDSF15X –OPDOT15X | Constructed |  
      | OPDTC15X | Total doctor charge (Imputed) | Constructed |  
      | IMPFLAG | Imputation status | Constructed |  Return To Table Of Contents 
Weights Variables
 
 
          | Variable | Description | Source |  
      | PERWT15F | Expenditure file person weight, 2015 | Constructed |  
      | VARSTR | Variance estimation stratum, 2015 | Constructed |  
      | VARPSU | Variance estimation PSU, 2015 | Constructed |  Return To Table Of Contents 
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