| 
 July 2016 
Agency for Healthcare Research and Quality 
Center for Financing, Access, and Cost Trends 
5600 Fishers Lane 
Rockville, MD 20857 
(301) 427-1406 
Table of Contents 
A. Data Use Agreement 
B. Background 
1.0 Household Component 
2.0 Medical Provider Component 
3.0 Survey Management and Data Collection 
C. Technical and Programming Information 
1.0 General Information 
2.0 Data File Information 
2.1 Codebook Structure 
2.2 Reserved Codes 
2.3 Codebook Format 
2.4 Variable Source and Naming Conventions 
2.4.1 General 
2.4.2 Expenditure and Source of Payment Variables 
2.5 File Contents 
2.5.1 Survey Administration Variables 
2.5.1.1 Person Identifiers (DUID, PID, DUPERSID) 
2.5.1.2 Record Identifiers (EVNTIDX, ERHEVIDX, FFEEIDX) 
2.5.1.3 Round Indicator (EVENTRN) 
2.5.1.4 Panel Indicator (PANEL) 
2.5.2 MPC Data Indicator (MPCDATA) 
2.5.3 Emergency Room Visit Event Variables 
2.5.3.1 Visit Details (ERDATEYR-VSTRELCN) 
2.5.3.2 Services, Procedures, and Prescription 
Medicines (LABTEST-MEDPRESC) 
2.5.4 Clinical Classification Codes (ERCCC1X-ERCCC4X) 
2.5.5 Flat Fee Variables (FFEEIDX, FFERTYPE, FFBEF14, 
FFTOT15) 
2.5.5.1 Definition of Flat Fee Payments 
2.5.5.2 Flat Fee Variable Descriptions 
2.5.5.2.1 Flat Fee ID (FFEEIDX) 
2.5.5.2.2 Flat Fee Type (FFERTYPE) 
2.5.5.2.3 Counts of Flat Fee Events that Cross Years 
(FFBEF14, FFTOT15) 
2.5.5.3 Caveats of Flat Fee Groups 
2.5.6 Expenditure Data 
2.5.6.1 Definition of Expenditures 
2.5.6.2 Data Editing and Imputation Methodologies of 
Expenditure Variables 
2.5.6.2.1 General Data Editing Methodology 
2.5.6.2.2 Imputation Methodologies 
2.5.6.2.3 Emergency Room Visit Data Editing and 
Imputation 
2.5.6.3 Imputation Flag (IMPFLAG) 
2.5.6.4 Flat Fee Expenditures 
2.5.6.5 Zero Expenditures 
2.5.6.6 Discount Adjustment Factor 
2.5.6.7 Emergency Room/Hospital Inpatient Stay 
Expenditures 
2.5.6.8 Sources of Payment 
2.5.6.9 Imputed Emergency Room Expenditure Variables 
2.5.6.9.1 Emergency Room Facility Expenditures 
(ERFSF14X-ERFOT14X, ERFXP14X, ERFTC14X) 
2.5.6.9.2 Emergency Room Physician Expenditures 
(ERDSF14X - ERDOT14X, ERDXP14X, ERDTC14X) 
2.5.6.9.3 Total Expenditures and Charges for Emergency 
Room Visits (ERXP14X, ERTC14X) 
2.5.7 Rounding 
3.0 Sample Weight (PERWT14F) 
3.1 Overview 
3.2 Details on Person Weight Construction 
3.2.1 MEPS Panel 18 Weight Development Process 
3.2.2 MEPS Panel 19 Weight Development Process 
3.2.3 The Final Weight for 2014 
3.2.4 Coverage 
3.3 Using MEPS Data for Trend 
Analysis 
4.0 Strategies for Estimation 
4.1 Developing Event-Level Estimates 
4.2 Person-Based Estimates for Emergency Room Visits 
4.3 Variables with Missing Values 
4.4 Variance Estimation (VARPSU, VARSTR) 
5.0 Merging/Linking MEPS Data Files 
5.1 Linking to the Person-Level File 
5.2 Linking to the Prescribed Medicines File 
5.3 Linking to the Medical Conditions File 
References 
D. Variable-Source Crosswalk 
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 dataset 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 dataset with individually 
				identifiable records from any datasets 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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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. 
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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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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). Datasets 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). 
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This documentation describes one in a series of public 
use event files from the 2014 Medical Expenditure Panel Survey (MEPS) Household 
Component (HC) and Medical Provider Component (MPC). Released as an ASCII data 
file (with related SAS, Stata, and SPSS programming statements) and a SAS 
transport file, the 2014 Emergency Room Visits (EROM) public use event file 
provides detailed information on emergency room visits for a nationally 
representative sample of the civilian noninstitutionalized population of the 
United States. Data from the EROM event file can be used to make estimates of 
emergency room utilization and expenditures for calendar year 2014. The file 
contains 65 variables and has a logical record length of 347 with an additional 
2-byte carriage return/line feed at the end of each record. As illustrated 
below, this file consists of MEPS survey data from the 2014 portion of Round 3, 
and Rounds 4 and 5 for Panel 18, as well as Rounds 1, 2 and the 2014 portion of 
Round 3 for Panel 19 (i.e., the rounds for the MEPS panels covering calendar 
year 2014).  
 
 Emergency room events reported in Panel 19 Round 3 and 
  known to have occurred after December 31, 2014 are not included on this file. In 
  addition to expenditures, each record contains household-reported medical 
  conditions associated with the emergency room visit. 
Annual counts of emergency room visits are based 
entirely on household reports. Information from the MEPS MPC is used to 
supplement expenditure and payment data reported by the household and does not 
affect use estimates.  
Data from the Emergency Room event file can be merged 
with other 2014 MEPS HC data files for purposes of appending person-level data 
such as demographic characteristics or health insurance coverage to each 
emergency room record. 
This file can also be used to construct summary 
variables of expenditures, sources of payment, and related aspects of emergency 
room visits. Aggregate annual person-level information on the use of emergency 
rooms and other health services is provided on the MEPS 2014 Full Year 
Consolidated Data file, where each record represents a MEPS sampled person.  
This documentation offers an overview of the types and 
levels of data provided, and the content and structure of the file and the 
codebook. It contains the following sections: 
    - Data File Information
 
    - Sample Weight
 
    - Strategies for Estimation
 
    - Merging/Linking MEPS Data Files
 
    - References
 
    - Variable - Source Crosswalk
 
 
Any variables not found on this file but released on 
previous years’ files 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 EROM file are available in 
the Survey Questionnaires section of the MEPS Web site at the following 
address: 
meps.ahrq.gov. 
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The 2014 Emergency Room Visits public use dataset 
consists of one event-level data file. The file contains characteristics 
associated with the EROM event and imputed expenditure data.  
The 2014 EROM public use dataset contains variables 
and frequency distributions for 7,236 emergency room visits reported during the 
2014 portion of Round 3 and Rounds 4 and 5 for Panel 18, as well as Rounds 1, 2, 
and the 2014 portion of Round 3 for Panel 19 of the MEPS Household Component. 
This file includes emergency room visit records for all household survey members 
who resided in eligible responding households and reported at least one 
emergency room visit. Records where the emergency room visit was known to have 
occurred after December 31, 2014 are not included on this file. Of these 7,236 
records, 6,959 were associated with persons having positive person-level weights 
(PERWT14F). The persons represented on this file had to meet either a) or b): 
  - Be classified as a key in-scope person who responded for his 
  or her entire period of 2014 eligibility (i.e., persons with a 
  positive 2014 full-year person-level weight (PERWT14F > 0)), or
 
  
  - Be an eligible member of a family all of whose key in-scope 
  members have a positive person-level weight (PERWT14F > 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 (FAMWT14F>0). Note that FAMIDYR and FAMWT14F 
  are variables on the 2014 Full Year Consolidated Data File.
 
 
Persons with no emergency room visit events for 2014 
are not included on this event-level ER file but are represented on the 
person-level 2014 Full Year Population Characteristics file.  
Each emergency room visit record includes the 
following: date of the visit; whether or not person saw doctor; type of care 
received; type of services (i.e., lab test, sonogram or ultrasound, x-rays, 
etc.) received; medicines prescribed during the visit; flat fee information; 
imputed sources of payment; total payment and total charge; a full-year 
person-level weight; variance strata; and variance PSU. 
To append person-level information such as demographic 
or health insurance coverage to each event record, data from this file can be 
merged with 2014 MEPS HC person-level data (e.g. Full Year Consolidated or Full 
Year Population Characteristics file) using the person identifier, DUPERSID. 
Emergency room visit events can also be linked to the MEPS 2014 Medical 
Conditions File and the MEPS 2014 Prescribed Medicines File. Please see Section 
5.0 and the 2014 Appendix File, HC-168I for details on how to merge MEPS data 
files. 
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For most variables on the Emergency Room Visits event 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 identifiers
 
    - Unique emergency room event identifiers
 
    - Emergency room characteristic variables
 
    - 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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The following reserved code values are used:
  
    
        | Value | 
        Definition | 
     
    
        | -1 INAPPLICABLE | 
        Question was not asked due to skip pattern | 
     
    
        | -7 REFUSED | 
        Question was asked and respondent refused to answer question | 
     
    
        | -8 DK | 
        Question was asked and respondent did not know answer | 
     
    
        | -9 NOT ASCERTAINED | 
        Interviewer did not record the data | 
     
 
Generally, values of -1, -7, -8, and -9 for 
non-expenditure variables have not been edited on this file. The values of -1 
and -9 can be edited by the data users/analysts by following the skip patterns 
in the HC survey questionnaire (located on the MEPS Web site: 
meps.ahrq.gov/survey_comp/survey_questionnaires.jsp).
 
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The EROM codebook describes an ASCII dataset (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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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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Variables on this file were derived from the HC 
questionnaire itself, derived from the MPC data collection instrument, derived 
from CAPI, or assigned in sampling. The source of each variable is identified in 
Section D “Variable - Source Crosswalk” in one of four ways: 
    - Variables derived from CAPI or assigned in sampling are 
    indicated as “CAPI derived” or “Assigned in sampling,” 
    respectively;
 
  
    - Variables which come from one or more specific questions 
    have those questionnaire sections and question numbers indicated 
    in the “Source” column; questionnaire sections are identified 
    as:
  
    - ER - Emergency Room section 
 
    - FF - Flat Fee section
 
    - CP - Charge Payment section;
 
  
  
    - Variables constructed from multiple questions using complex 
    algorithms are labeled “Constructed” in the “Source” column; and
 
  
    - Variables which have been edited or imputed are so 
    indicated.
 
 
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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 ER file, the third 
character indicates whether the expenditure is associated with the facility (F) 
or the physician (D). 
In the case of the source of payment variables, the 
fourth and fifth characters indicate: 
- SF - self or family
 
- MR - Medicare
 
- MD - Medicaid
 
- PV - private insurance
 
- VA - Veterans Administration/CHAMPVA
 
- TR - TRICARE
 
- OF - other federal government
 
- SL - state/local government
 
- WC - Workers’ Compensation
 
- OT - other insurance
 
- OR - other private
 
- OU - other public
 
- XP - sum of payments
 
 
In addition, the total charge variable is indicated by 
TC in the variable name. 
The sixth and seventh characters indicate the year 
(14). The eighth character, “X”, indicates whether the variable is 
edited/imputed. 
For example, ERFSF14X is the edited/imputed amount 
paid by self or family for the facility portion of the expenditure associated 
with an emergency room visit.  
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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 2014 Full Year Population Characteristics file. 
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EVNTIDX uniquely identifies each emergency room 
visit/event (i.e., each record on the Emergency Room Visits file) and is the 
variable required to link emergency room events to data files containing details 
on conditions and/or prescribed medicines (MEPS 2014 Medical Conditions File and 
the MEPS 2014 Prescribed Medicines File, respectively). For details on linking, 
see Section 5.0 or the MEPS 2014 Appendix File, HC-168I. 
ERHEVIDX is a constructed variable identifying an EROM 
record that has its facility expenditures represented on an associated hospital 
inpatient stay record. This variable is derived from provider-reported 
information on linked emergency room and inpatient stay events that matched to 
corresponding events reported by the household. The variable ERHEVIDX contains 
the EVNTIDX of the linked event. On the 2014 EROM file, there are 413 emergency 
room events linked to subsequent hospital stays. Please note that where the 
emergency room visit is associated with a hospital stay (and its expenditures 
and charges are included with the hospital stay), the physician expenditures 
associated with the emergency room visit remain on the Emergency Room Visits 
file. 
FFEEIDX is a constructed variable which uniquely 
identifies a flat fee group, that is, all events that were a part of a flat fee 
payment.  
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EVENTRN indicates the round in which the emergency 
room visit was reported. Please note: Rounds 3, 4, and 5 are associated with 
MEPS survey data collected from Panel 18. Likewise, Round 1, 2, and 3 are 
associated with data collected from Panel 19. 
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PANEL is a constructed variable used to specify the 
panel number for the person. PANEL will indicate either Panel 18 or Panel 19 for 
each person on the file. Panel 18 is the panel that started in 2013, and Panel 
19 is the panel that started in 2014. 
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MPCDATA is a constructed variable which indicates 
whether or not MPC data were collected for the emergency room visit. While all 
emergency room events are sampled into the Medical Provider Component, not all 
emergency room event records have MPC data associated with them. This is 
dependent upon the cooperation of the household respondent to provide permission 
forms to contact the emergency room facility as well as the cooperation of the 
emergency room facility to participate in the survey. 
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This file contains variables describing emergency room 
visits/events reported by household respondents in the Emergency Room section of 
the MEPS HC questionnaire. The questionnaire contains specific probes for 
determining details about the emergency room event. These variables have not 
been edited. 
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When a person reported having had a visit to the 
emergency room, the year and month of the emergency room visit was recorded (ERDATEYR 
and ERDATEMM respectively). The type of care the person received (VSTCTGRY) and 
whether or not the visit was related to a specific condition (VSTRELCN) were 
also determined. Through 2012, whether or not the person saw a medical doctor (SEEDOC) 
was included on the file. Beginning in 2013, SEEDOC was removed because of 
design changes. 
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Services received during the visit included whether or 
not the person received lab tests (LABTEST), a sonogram or ultrasound 
(SONOGRAM), x-rays (XRAYS), a mammogram (MAMMOG), an MRI or CAT scan (MRI), an 
electrocardiogram (EKG), an electroencephalogram (EEG), a vaccination (RCVVAC), 
anesthesia (ANESTH), throat swab (THRTSWAB), or other diagnostic tests or exams 
(OTHSVCE). Whether or not a surgical procedure was performed during the visit 
was asked (SURGPROC). The questionnaire determined if a medicine was prescribed 
for the person during the emergency room visit (MEDPRESC). See Section 5.2 for 
information on linking to the prescribed medicines events file. 
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Information on household-reported medical conditions 
associated with each emergency room visit is provided on this file. There are up 
to four CCS codes (ERCCC1X-ERCCC4X) listed for each emergency room 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 for 
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 condition information 
associated with an event, the data user/analyst must link to the MEPS 2014 
Medical Conditions File. Details on how to link the 2014 EROM event file to the 
MEPS 2014 Medical Conditions File are provided in Section 5.3 and in the MEPS 
2014 Appendix File, HC-168I. The data user/analyst should note that 
because of 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 2014 ICD-9-CM codes, including medical 
conditions and V codes (Health Care Financing Administration, 1980) by 
professional coders. Although codes were verified and error rates did not exceed 
2 percent for any coder, data users/analysts should not presume this level of 
precision in the data; the ability of household respondents to report condition 
data that can be coded accurately should not be assumed (Cox and Cohen, 1985; 
Cox and Iachan, 1987; Edwards, et al, 1994; and Johnson and Sanchez, 1993). For 
detailed information on how conditions were coded, please refer to the 
documentation on the MEPS 2014 Medical Conditions File. For frequencies of 
conditions by event type, please see the MEPS 2014 Appendix File, HC-168I. 
The ICD-9-CM condition codes were aggregated into 
clinically meaningful categories. These categories, included on the file as 
ERCCC1X-ERCCC4X, 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 
emergency room visit are sequenced in the order in which the conditions were 
reported by the household respondent, which was in order of input into the 
database and not in order of importance or severity. Data users/analysts who use 
the MEPS 2014 Medical Conditions File in conjunction with this emergency room 
visits file should note that the order of conditions on this file is not 
identical to that on the Medical Conditions file. 
Analysts should use the clinical classification codes 
listed in the Conditions PUF document (HC-170) and the Appendix to the Event 
Files (HC-168I) 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 2014 MEPS PUFs, these updates 
will not be reflected in the 2014 MEPS data. 
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A flat fee is the fixed dollar amount a person is 
charged for a package of health care services provided during a defined period 
of time. Examples would be: obstetrician’s fee covering a normal delivery, as 
well as pre- and post-natal care; or a surgeon’s fee covering a surgical 
procedure and post-surgical care. A flat fee group is the set of medical 
services (i.e., events) that are covered under the same flat fee payment. The 
flat fee groups represented on this file include flat fee groups where at least 
one of the health care events, as reported by the HC respondent, occurred during 
2014. By definition, a flat fee group can span multiple years. Furthermore, a 
single person can have multiple flat fee groups. 
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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 2014 MEPS event file, every 
event that was a part of a specific flat fee group will have the same value for 
FFEEIDX. Note that prescribed medicine and home health events are never included 
in a flat fee group and FFEEIDX is not a variable on those event files. 
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FFERTYPE indicates whether the 2014 emergency room 
visit is the “stem” or “leaf” of a flat fee group. A stem (records with FFERTYPE 
= 1) is the initial medical service (event) which is followed by other medical 
events that are covered under the same flat fee payment. The leaves of the flat 
fee group (records with FFERTYPE = 2) are those medical events that are tied 
back to the initial medical event (the stem) in the flat fee group. These “leaf” 
records have their expenditure variables set to zero. For the emergency room 
visits that are not part of a flat fee payment, the FFERTYPE is set to –1, 
“INAPPLICABLE.” 
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As described in Section 2.5.5.1, a flat fee payment 
may cover multiple events, and the multiple events could span multiple years. 
For situations where the emergency room event occurred in 2014 as part of a 
group of events, and some event occurred before or after 2014, counts of the 
known events are provided on the emergency room record. Variables indicating 
events that occurred before or after 2014 are as follows: 
    - FFBEF14 – total number of pre-2014 events in the same 
        flat fee group as the 2014 emergency room visit(s). This count would not include 
        the 2014 emergency room visit(s).
 
  
    - FFTOT15 –the number of 2015 emergency room visits, 
        expected to be in the same flat fee group as the emergency room event that 
        occurred in 2014. 
 
 
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There are 16 emergency room visits that are identified 
as being part of a flat fee payment group. In general, every flat fee group 
should have an initial visit (stem) and at least one subsequent visit (leaf). 
There are some situations where this is not true. For some flat fee groups, the 
initial visit reported occurred in 2014, but the remaining visits that were part 
of this flat fee group occurred in 2015. In this case, the 2014 flat fee group 
represented on this file would consist of one event, the stem. The 2015 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 2013 but subsequent visits occurred during 2014. In this case, 
the initial visit would not be represented on the file. This 2014 flat fee group 
would then only consist of one or more leaf records and no stem. Please note 
that the crosswalk in this document lists all possible flat fee variables. 
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Expenditures on this file refer to what is paid for 
health care services. More specifically, expenditures in MEPS are defined as the 
sum of payments for care received for each emergency room visit, including 
out-of-pocket payments and payments made by private insurance, Medicaid, 
Medicare, and other sources. The definition of expenditures used in MEPS differs 
slightly from its predecessors: the 1987 NMES and 1977 NMCES surveys where 
“charges” rather than sum of payments were used to measure expenditures. This 
change was adopted because charges became a less appropriate proxy for medical 
expenditures during the 1990s due to the increasingly common practice of 
discounting. Although measuring expenditures as the sum of payments incorporates 
discounts in the MEPS expenditure estimates, the estimates do not incorporate 
any payment not directly tied to specific medical care visits, such as bonuses 
or retrospective payment adjustments by third party payers. 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. While charge data 
are provided on this file, data users/analysts should use caution when working 
with these data because a charge does not typically represent actual dollars 
exchanged for services or the resource costs of those services; nor are they 
directly comparable to the expenditures defined in the 1987 NMES. For details on 
expenditure definitions, please reference “Informing American Health Care 
Policy” (Monheit et al., 1999). AHRQ has developed factors to apply to the 1987 
NMES expenditure data to facilitate longitudinal analysis. These factors can be 
accessed via the CFACT data center. For more information, see the Data Center 
section of the MEPS Web site 
meps.ahrq.gov/data_stats/onsite_datacenter.jsp. 
Expenditure data related to emergency room visits are 
broken out by facility and separately billing doctor expenditures. This file 
contains six categories of expenditure variables per visit: basic hospital 
emergency room facility expenses; expenses for doctors who billed separately 
from the hospital for any emergency room services provided during the emergency 
room visit; total expenses, which is the sum of the facility and physician 
expenses; facility charge; physician charge; and total charges, which is the sum 
of the facility and physician charges. If examining trends in MEPS expenditures, 
please refer to Section 3.3 for more information.  
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The expenditure data included on this file were 
derived from both the MEPS Household (HC) and 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 emergency room 
visits, MPC data were used if available; otherwise, HC data were used. Missing 
data for emergency room visits, where HC data were not complete and MPC data 
were not collected, or MPC data were not complete, were imputed through the 
imputation process.  
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Logical edits were used to resolve internal 
inconsistencies and other problems in the HC and MPC survey-reported data. The 
edits were designed to preserve partial payment data from households and 
providers, and to identify actual and potential sources of payment for each 
household-reported event. In general, these edits accounted for outliers, 
copayments or charges reported as total payments, and reimbursed amounts that 
were reported as out-of-pocket payments. In addition, edits were implemented to 
correct for misclassifications between Medicare and Medicaid and between 
Medicare HMOs and private HMOs as payment sources. These edits produced a 
complete vector of expenditures for some events, and provided the starting point 
for imputing missing expenditures in the remaining events.  
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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 imputations for the flat fee events were carried 
out separately from the simple events. 
The weighted sequential hot-deck procedure was used to 
impute the missing total charges. This procedure uses survey data from 
respondents to replace missing data while taking into account the persons’ 
weighted distribution in the imputation process.  
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Facility expenditures for emergency room services were 
developed in a sequence of logical edits and imputations. “Household” edits were 
applied to sources and amounts of payment for all events reported by HC 
respondents. “MPC” edits were applied to provider-reported sources and amounts 
of payment for records matched to household-reported events. Both sets of edits 
were used to correct obvious errors in the reporting of expenditures. After the 
data from each source were edited, a decision was made as to whether household- 
or MPC-reported information would be used in the final editing and predictive 
mean matching imputations for missing expenditures. The general rule was that 
MPC data would be used where a household-reported event corresponded to an MPC-reported 
event (i.e., a matched event), since providers usually have more complete and 
accurate data on sources and amounts of payment than households. 
One of the more important edits separated flat fee 
events from simple events. This edit was necessary because groups of events 
covered by a flat fee (i.e., a flat fee bundle) were edited and imputed 
separately from individual events covered by a single charge (i.e., simple 
events). Most emergency room events were imputed as simple events because 
hospital facility charges are rarely bundled with other events. (See Section 
2.5.5 for more details on flat fee groups). However, some emergency room visits 
were treated as free events because the person was admitted to a hospital 
through its emergency room. In these cases, emergency room charges are included 
in the charge for an inpatient hospital stay. 
Logical edits also were used to sort each event into a 
specific category for the imputations. Events with complete expenditures were 
flagged as potential donors for the predictive mean matching imputations, while 
events with missing expenditure data were assigned to various recipient 
categories. Each event with missing expenditure data was assigned to a recipient 
category based on the extent of its missing charge and expenditure data. For 
example, an event with a known total charge but no expenditure information was 
assigned to one category, while an event with a known total charge and partial 
expenditure information was assigned to a different category. Similarly, events 
without a known total charge and no or partial expenditure information were 
assigned to various recipient categories.  
The logical edits produced eight recipient categories 
in which all events had a common extent of missing data. Separate predictive 
mean matching imputations were performed on events in each recipient category. 
For emergency room 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). 
Expenditures for some emergency room visits are not 
shown because the person was admitted to the hospital through the emergency 
room. These emergency room events are not free, but the expenditures are 
included in the inpatient stay expenditures. The variable ERHEVIDX can be used 
to differentiate between free emergency room care and situations where the 
emergency room charges have been included in the inpatient hospital charges. 
Expenditures for services provided by separately 
billing doctors in hospital settings were also edited and imputed. These 
expenditures are shown separately from hospital facility charges for hospital 
inpatient, outpatient, and emergency room care.  
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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 (not applicable to ER events)
 
 
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The approach used to count expenditures for flat fees 
was to place the expenditure on the first visit of the flat fee group. The 
remaining visits have zero facility payments, while physician’s expenditures may 
still be present. Thus, if the first visit in the flat fee group occurred prior 
to 2014, all of the events that occurred in 2014 will have zero payments. 
Conversely, if the first event in the flat fee group occurred at the end of 
2014, the total expenditure for the entire flat fee group will be on that event, 
regardless of the number of events it covered after 2014. See Section 2.5.5 for 
details on the flat fee variables. 
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There are some medical events reported by respondents 
where the payments were zero. Zero payment events can occur in MEPS for the 
following reasons: (1) the stay was covered under a flat fee arrangement (flat 
fee payments are included only on the first event covered by the arrangement), 
(2) there was no charge for a follow-up stay, (3) the provider was never paid by 
an individual, insurance plan, or other source for services provided, (4) 
charges were included in the bill for a subsequent hospital admission (emergency 
room events only), or (5) the event was paid for through government or 
privately-funded research or clinical trials. 
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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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It is common for an emergency room visit to result in 
a hospital stay. While it is true that all of the event files can be linked by 
DUPERSID, there is no unique record link between hospital inpatient stays and 
emergency room visits. However, wherever this relationship could be identified 
(using the MPC start and end dates of the events as well as other information 
from the provider), the facility expenditure associated with the emergency room 
visit is included in the hospital facility expenditure. Hence, the expenditures 
(and charges) for some emergency room visits are included in the resulting 
hospitalization. In these situations, the emergency room record on this file 
will have its expenditure (and charge) information zeroed out to avoid 
double-counting while its corresponding hospital inpatient stay record on the 
MEPS 2014 Hospital Inpatient Stays File will have the combined expenditures. 
Please note that any physician expenditures associated with emergency room 
events remain on the Emergency Room event file. The variable ERHEVIDX identifies 
the emergency room visits whose facility expenditures are included in the 
expenditures for the following hospital inpatient stay. It should also be noted 
that for these cases there is only one emergency room stay associated with the 
hospital room stay. 
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In addition to total expenditures, variables are 
provided which itemize expenditures according to major source of payment 
categories. These categories are: 
      - Out-of-pocket by User or Family,
 
      - Medicare,
 
      - Medicaid,
 
      - Private Insurance,
 
      - Veterans Administration/CHAMPVA,
 
      - TRICARE, 
 
      - Other Federal Sources - includes Indian Health Service, 
      military treatment facilities, and other care by the federal 
      government,
 
      - Other State and Local Source - includes community and 
      neighborhood clinics, state and local health departments, and 
      state programs other than Medicaid,
 
      - Workers’ Compensation, and
 
      - Other Unclassified Sources - includes sources such as 
      automobile, homeowner’s, and liability insurance, and other 
      miscellaneous or unknown sources.
 
 
Two additional source of payment 
      variables were created to classify payments for events with 
      apparent inconsistencies between health insurance coverage and 
      sources of payment based on data collected in the survey. These 
      variables include: 
      - Other Private - any type of private insurance payments 
      reported for persons not reported to have any private health 
      insurance coverage during the year as defined in MEPS, and
 
      - Other Public – Medicare/Medicaid payments reported for 
      persons who were not reported to be enrolled in the 
      Medicare/Medicaid program at any time during the year.
 
 
Though these two sources are relatively small in 
magnitude, data users/analysts should exercise caution when interpreting the 
expenditures associated with these two additional sources of payment. While 
these payments stem from apparent inconsistent responses to health insurance and 
source of payment questions in the survey, some of these inconsistencies may 
have logical explanations. For example, private insurance coverage in MEPS is 
defined as having a major medical plan covering hospital and physician services. 
If a MEPS sampled person did not have such coverage but had a single service 
type insurance plan (e.g., dental insurance) that paid for a particular episode 
of care, those payments may be classified as “other private.” Some of the “other 
public” payments may stem from confusion between Medicaid and other state and 
local programs or may be from persons who were not enrolled in Medicaid, but 
were presumed eligible by a provider who ultimately received payments from the 
public payer. 
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This file contains two sets of imputed expenditure 
variables: facility expenditures and physician expenditures.  
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Emergency room expenses include all expenses for 
treatment, services, tests, diagnostic and laboratory work, x-rays, and similar 
charges, as well as any physician services included in the emergency room 
charge. 
ERFSF14X - ERFOT14X are the 12 sources of 
payment. The 12 sources of payment are: self/family (ERFSF14X), Medicare 
(ERFMR14X), Medicaid (ERFMD14X), private insurance (ERFPV14X), Veterans 
Administration/CHAMPVA (ERFVA14X), TRICARE (ERFTR14X), other federal sources 
(ERFOF14X), state and local (non-federal) government sources (ERFSL14X), 
Worker’s Compensation (ERFWC14X), other private insurance (ERFOR14X), other 
public insurance (ERFOU14X), and other insurance (ERFOT14X). ERFXP14X is the sum 
of the 12 sources of payment for the emergency room expenditures, and ERFTC14X 
is the total charge. Please note that where an emergency room visit record is 
linked to a hospital inpatient stay record, all facility sources of payment 
variables, as well as ERFTC14X, have been zeroed out.  
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Separately billing doctor (SBD) expenses typically 
cover services provided to patients in hospital settings by providers like 
anesthesiologists, radiologists, and pathologists, whose charges are often not 
included in emergency room visit bills.  
For physicians who bill separately (i.e., outside the 
emergency room visit bill), a separate data collection effort within the Medical 
Provider Component was performed to obtain this same set of expenditure 
information from each separately billing doctor. It should be noted that there 
could be several separately billing doctors associated with a medical event. For 
example, an emergency room visit could have a radiologist and an internist 
associated with it. If their services are not included in the emergency room 
visit bill then this is one medical event with two separately billing doctors. 
The imputed expenditure information associated with the separately billing 
doctors was summed to the event level and is provided on the file. ERDSF14X - 
ERDOT14X are the 12 sources of payment, ERDXP14X is the sum of the 12 sources of 
payments, and ERDTC14X 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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Data users/analysts interested in total expenditure 
should use the variable ERXP14X, which includes both the facility and physician 
amounts. Those interested in total charges should use the variable ERTC14X, 
which includes both facility and physician charges (see Section 2.5.6.1 for an 
explanation of the “charge” concept). However, please note that where the 
emergency room visit is linked to a hospital inpatient stay record, ERFTC14X has 
been zeroed out. Thus, ERTC14X may be equal to “0” or the doctor total charge 
(ERDTC14X). 
Return To Table Of Contents 
The expenditure variables have been rounded to the 
nearest penny. Person-level expenditure information released on the MEPS 2014 
Person-Level Use and Expenditure File were rounded to the nearest dollar. It 
should be noted that using the MEPS 2014 event files to create person-level 
totals will yield slightly different totals than those found on the full year 
consolidated file. These differences are due to rounding only. Moreover, 
in some instances, the number of persons having expenditures on the event files 
for a particular source of payment may differ from the number of persons with 
expenditures on the person-level expenditures file for that source of payment. 
This difference is also an artifact of rounding only. 
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There is a single full year person-level weight 
(PERWT14F) 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 2014. A 
key person either was a member of a responding NHIS household at the time of 
interview, or joined a family associated with such a household after being 
out-of-scope at the time of the NHIS (the latter circumstance includes newborns 
as well as those returning from military service, an institution, or residence 
in a foreign country). A person is in-scope whenever he or she is a member of 
the civilian noninstitutionalized portion of the U.S. population. 
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The person-level weight PERWT14F was developed in 
several stages. First, person-level weights for Panel 18 and Panel 19 were 
created separately. The weighting process for each panel included and adjustment 
for nonresponse over time and calibration to independent population totals. 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 2014 composite weight was then formed by 
multiplying each weight from Panel 18 by the factor .500 and each weight from 
Panel 19 by the factor .500. 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.  
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The person-level weight for MEPS Panel 18 was 
developed using the 2013 full year weight for an individual as a “base” weight 
for survey participants present in 2013. For key, in-scope members who joined an 
RU some time in 2014 after being out-of-scope in 2013, the initially assigned 
person-level weight was the corresponding 2013 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 2014 for key, 
responding persons in-scope on December 31, 2014. These control totals were 
derived by scaling back the population distribution obtained from the March 2015 
CPS to reflect the December 31, 2014 estimated population total (estimated based 
on Census projections for January 1, 2015). 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, 
2014 but were in-scope earlier in the year was the person weight after the 
nonresponse adjustment. 
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The person-level weight for MEPS Panel 19 was 
developed using the 2014 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 2014 as well as 
raking to the same population control figures for December 2014 used for the 
MEPS Panel 18 weights for key, responding persons in-scope on December 31, 2014. 
The same five variables employed for Panel 18 raking (census region, MSA status, 
race/ethnicity, sex, and age) were used for Panel 19 raking. Again, the final 
weight for key, responding persons who were not in-scope on December 31, 2014 
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. 
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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, 2014 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 
2014 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, 2014 is 314,906,436 
(PERWT14F>0 and INSC1231=1). The sum of the person-level weights across all 
persons assigned a positive person-level weight is 318,440,423.  
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The target population for MEPS in this file is the 
2014 U.S. civilian noninstitutionalized population. However, the MEPS sampled 
households are a subsample of the NHIS households interviewed in 2012 (Panel 18) 
and 2013 (Panel 19). New households created after the NHIS interviews for the 
respective panels and consisting exclusively of persons who entered the target 
population after 2012 (Panel 18) or after 2013 (Panel 19) 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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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 2013-14), 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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The data in this file can be used to develop national 
2014 event-level estimates for the U.S. civilian noninstitutionalized population 
on emergency room visits as well as expenditures, and sources of payment for 
these visits. Estimates of total visits are the sum of the weight variable 
(PERWT14F) across relevant event records while estimates of other variables must 
be weighted by PERWT14F to be nationally representative. The tables below 
contain event-level estimates for selected variables.  
Selected Event-Level Estimates 
Emergency Room Visits
  
    
        | Estimate of Interest | 
        Variable Name | 
        Estimate (SE) | 
        Estimate Excluding  Zero Payment Events (SE) | 
     
    
        | 
        Total number of 
        emergency room visits (in millions) | 
        PERWT14F | 
        65.6 (1.99) | 
        61.6 (1.90) | 
     
    
        | 
        Proportion of 
        emergency room visits with expenditures > 0* | 
        ERXP14X | 
        0.940 (0.0052) | 
        -- | 
     
 
  
Emergency Room Expenditures
  
    
        | Estimate of Interest | 
        Variable Name | 
        Estimate (SE) | 
        Estimate Excluding 
        Zero Payment Events (SE)* | 
     
    
        | 
        Mean total payments per visit  | 
        ERXP14X | 
        $997 ($38.1) | 
        $1,060 ($41.4) | 
     
    
        | 
        Mean out-of-pocket payment per visit  | 
        ERDSF14X +ERFSF14X | 
        $90 ($6.4) | 
        $95 ($6.8) | 
     
    
        | 
        Mean proportion of total expenditures paid by private insurance per 
        visit  | 
        (ERDPV14X+ERFPV14X) 
        /ERXP14X | 
        -- | 
        0.306 (0.0111) | 
     
 
* Zero payment events can occur in MEPS for the 
following reasons: (1) the stay was covered under a flat fee arrangement (flat 
fee payments are included only on the first event covered by the arrangement), 
(2) there was no charge for a follow-up stay, (3) the provider was never paid by 
an individual, insurance plan, or other source for services provided, (4) 
charges were included in the bill for a subsequent hospital admission (emergency 
room events only), or (5) the event was paid for through government or 
privately-funded research or clinical trials. 
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To enhance analyses of emergency room visits, analysts 
may link information about emergency room visits by sample persons in this file 
to the annual full year consolidated file (which has data for all MEPS sample 
persons), or conversely, link person-level information from the full year 
consolidated file to this event-level file (see Section 5 below for more 
details). Both this file and the full year consolidated file may be used to 
derive estimates for persons with emergency room care and annual estimates of 
total expenditures. However, if the estimate relates to the entire population, 
this file cannot be used to calculate the denominator, as only those persons 
with at least one emergency room event are represented on this data file. 
Therefore, the full year consolidated file must be used for person-level 
analyses that include both persons with and without emergency room care.  
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It is essential that the analyst examine all variables 
for the presence of negative values used to represent missing values. For 
continuous or discrete variables, where means or totals may be taken, it may be 
necessary to set negative values to values appropriate to the analytic needs. 
That is, the analyst should either impute a value or set the value to one that 
will be interpreted as missing by the 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. 
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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.
 
 
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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 a 
person-level file (e.g., MEPS 2014 Full Year Consolidated File) expands the 
scope of potential estimates. For example, to estimate the total number of 
emergency room visits for persons with specific demographic characteristics 
(e.g., age, race, sex, and education), population characteristics from a 
person-level file need to be merged onto the emergency room visit file. This 
procedure is illustrated below. The MEPS 2014 Appendix File, HC-168I, provides 
additional detail on how to merge MEPS data files. 
    - Create dataset PERSX by sorting the MEPS 2014 Full Year 
    Consolidated File by the person identifier, DUPERSID. Keep only 
    variables to be merged onto the emergency room visit file and 
    DUPERSID.
 
  
    - Create dataset EROM by sorting the emergency room visit file 
    by person identifier, DUPERSID.
 
  
    - Create final dataset NEWEROM by merging these two files by 
    DUPERSID, keeping only records on the emergency room visit file.
 
 
The following is an example of SAS code which 
completes these steps: 
PROC SORT DATA=HCXXX (KEEP=DUPERSID AGE31X AGE42X 
AGE53X SEX RACEV1X EDUYRDG EDRECODE) OUT=PERSX; 
BY DUPERSID; 
RUN; 
PROC SORT DATA=EROM; 
BY DUPERSID; 
RUN; 
DATA NEWEROM; 
MERGE EROM (IN=A) PERSX (IN=B); 
BY DUPERSID; 
IF A; 
RUN; 
Return To Table Of Contents 
The prescribed medicines-event link (RXLK) file 
provides a link from the MEPS event files to the 2014 Prescribed Medicines Event 
File. When using RXLK, data users/analysts should keep in mind that one 
inpatient stay can link to more than one prescribed medicine record. Conversely, 
a prescribed medicine event may link to more than one inpatient stay visit or 
different types of events. When this occurs, it is up to the data user/analyst 
to determine how the prescribed medicine expenditures should be allocated among 
those medical events. For detailed linking examples, including SAS code, data 
users/analysts should refer to the MEPS 2014 Appendix File, HC-168I. 
Return To Table Of Contents 
The conditions-event link (CLNK) file provides a link 
from MEPS event files to the 2014 Medical Conditions File. When using the CLNK, 
data users/analysts should keep in mind that (1) conditions are 
household-reported, (2) there may be multiple conditions associated with an 
emergency room visit, and (3) a condition may link to more than one emergency 
room visit or any other type of visit. Data users/analysts should also note that 
not all emergency room visits link to the medical conditions file. 
Return To Table Of Contents 
Cohen, S.B. (1998). Sample Design of the 1996 Medical 
Expenditure Panel Survey Medical Provider Component. Journal of Economic 
Social Measurement. Vol. 24, 25-53. 
Cohen, S.B. (1996). The Redesign of the Medical 
Expenditure Panel Survey: A Component of the DHHS Survey Integration Plan. 
Proceedings of the COPAFS Seminar on Statistical Methodology in the Public 
Service. 
Cox, B.G. and Cohen, S.B. (1985). Chapter 6: A 
Comparison of Household and Provider Reports of Medical Conditions. In 
Methodological Issues for Health Care Surveys. Marcel Dekker, New York. 
Cox, B. and Iachan, R. (1987). A Comparison of 
Household and Provider Reports of Medical Conditions. Journal of Economic and 
Social Measurement. 82(400):1013-18. 
Edwards, W.S., Winn, D.M., Kurlantzick V., et al. 
(1994). Evaluation of National Health Interview Survey Diagnostic Reporting. 
National Center for Health Statistics, Vital Health 2(120).  
Elixhauser A., Steiner C.A., Whittington C.A., and 
McCarthy E. Clinical Classifications for Health Policy Research: Hospital 
Inpatient Statistics, 1995. Healthcare Cost and Utilization Project, HCUP-3 
Research Note. Rockville, MD: Agency for Health Care Policy and Research; 1998. 
AHCPR Pub. No. 98-0049. 
Ezzati-Rice, T.M., Rohde, F., Greenblatt, J., Sample 
Design of the Medical Expenditure Panel Survey Household Component, 1998–2007.
Methodology Report No. 22. March 2008. Agency for Healthcare Research and 
Quality, Rockville, MD.  
Health Care Financing Administration (1980). 
International Classification of Diseases, 9th Revision, Clinical 
Modification (ICD-CM). Vol. 1. (DHHS Pub. No. (PHS) 80-1260). DHHS: U.S. Public 
Health Services. 
Johnson, A.E. and Sanchez, M.E. (1993). Household and 
Medical Provider Reports on Medical Conditions: National Medical Expenditure 
Survey, 1987. Journal of Economic and Social Measurement. Vol. 19, 
199-233.  
Monheit, A.C., Wilson, R., and Arnett, III, R.H. 
(Editors). Informing American Health Care Policy. (1999). Jossey-Bass 
Inc., San Francisco. 
Shah, B.V., Barnwell, B.G., Bieler, G.S., Boyle, K.E., 
Folsom, R.E., LaVange, L., Wheeless, S.C., and Williams, R. (1996). Technical 
Manual: Statistical Methods and Algorithms Used in SUDAAN Release 7.0, 
Research Triangle Park, NC: Research Triangle Institute. 
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VARIABLE-SOURCE CROSSWALK
  
FOR MEPS HC-168E: 2014 EMERGENCY ROOM VISITS
Survey Administration Variables
  
    
        | Variable | 
        Description | 
        Source | 
     
	
		| DUID | 
        Dwelling unit ID | 
        Assigned in sampling | 
     
    
        | PID | 
        Person number | 
        Assigned in sampling | 
     
    
        | DUPERSID | 
        Person ID (DUID + PID) | 
        Assigned in sampling | 
     
    
        | EVNTIDX | 
        Event ID | 
        Assigned in sampling | 
     
    
        | EVENTRN | 
        Event round number | 
        CAPI derived | 
     
    
        | ERHEVIDX | 
        Event ID for 
        corresponding hospital stay | 
        Constructed | 
     
    
        | FFEEIDX | 
        Flat fee ID | 
        CAPI derived | 
     
    
        | PANEL | 
        Panel Number | 
        Constructed | 
     
    
        | MPCDATA | 
        MPC data flag | 
        Constructed | 
     
 
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Emergency Room Visit Event Variables
  
    
        | Variable | 
        Description | 
        Source | 
     
	
		| ERDATEYR | 
        Event date – year | 
        CAPI derived | 
     
    
        | ERDATEMM | 
        Event date – month | 
        CAPI derived | 
     
    
        | VSTCTGRY | 
        Best category for care p recv on vst dt | 
        ER02 | 
     
    
        | VSTRELCN | 
        This vst related to spec condition | 
        ER03 | 
     
    
        | LABTEST | 
        This visit did p have lab tests | 
        ER05 | 
     
    
        | SONOGRAM | 
        This visit did p have sonogram or ultrsd | 
        ER05 | 
     
    
        | XRAYS | 
        This visit did p have x–rays | 
        ER05 | 
     
    
        | MAMMOG | 
        This visit did p have a mammogram | 
        ER05 | 
     
    
        | MRI | 
        This visit did p have an MRI/Catscan | 
        ER05 | 
     
    
        | EKG  | 
        This visit did p have an EKG or ECG | 
        ER05 | 
     
    
        | EEG | 
        This visit did p have an EEG | 
        ER05 | 
     
    
        | RCVVAC | 
        This visit did p receive a vaccination | 
        ER05 | 
     
    
        | ANESTH | 
        This visit did p receive anesthesia | 
        ER05 | 
     
    
        | THRTSWAB | 
        This visit did p have a throat swab | 
        ER05 | 
     
    
        | OTHSVCE | 
        This visit did p have oth diag tests/exams | 
        ER05 | 
     
    
        | SURGPROC | 
        Was surg proc 
        performed on p this visit | 
        ER06 | 
     
    
        | MEDPRESC | 
        Any medicine prescribed for p this visit | 
        ER08 | 
     
    
        | ERCCC1X | 
        Modified Clinical Classification Code | 
        Constructed/Edited | 
     
    
        | ERCCC2X | 
        Modified Clinical Classification Code | 
        Constructed/Edited | 
     
    
        | ERCCC3X | 
        Modified Clinical Classification Code | 
        Constructed/Edited | 
     
    
        | ERCCC4X | 
        Modified Clinical Classification Code | 
        Constructed/Edited | 
     
 
Return To Table Of Contents 
Flat Fee Variables
  
    
        | Variable | 
        Description | 
        Source | 
     
    
        | FFERTYPE | 
        Flat fee bundle | 
        Constructed | 
     
    
        | FFBEF14 | 
        Total # of visits in FF before 2014 | 
        FF05 | 
     
    
        | FFTOT15 | 
        Total # of visits in FF after 2014 | 
        FF10 | 
     
 
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Imputed Total Expenditure Variables
  
    
        | Variable | 
        Description | 
        Source | 
     
    
        | ERXP14X | 
        Total exp for event (ERFXP14X + ERDXP14X) | 
        Constructed | 
     
    
        | ERTC14X | 
        Total chg for event (ERFTC14X + ERDTC14X) | 
        Constructed | 
     
 
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Imputed Facility Expenditure Variables
  
    
        | Variable | 
        Description | 
        Source | 
     
    
        | ERFSF14X | 
        Facility amt pd, family (Imputed) | 
        CP Section (Edited) | 
     
    
        | ERFMR14X | 
        Facility amt pd, Medicare (Imputed) | 
        CP Section (Edited) | 
     
    
        | ERFMD14X | 
        Facility amt pd, Medicaid (Imputed) | 
        CP Section (Edited) | 
     
    
        | ERFPV14X | 
        Facility amt pd, priv insur (Imputed) | 
        CP Section (Edited) | 
     
    
        | ERFVA14X | 
        Facility amt pd, Veterans/CHAMPVA (Imputed) | 
        CP Section (Edited) | 
     
    
        | ERFTR14X | 
        Facility amt pd, TRICARE (Imputed) | 
        CP Section (Edited) | 
     
    
        | ERFOF14X | 
        Facility amt pd, oth federal (Imputed) | 
        CP Section (Edited) | 
     
    
        | ERFSL14X | 
        Facility amt pd, state/local gov (Imputed) | 
        CP Section (Edited) | 
     
    
        | ERFWC14X | 
        Facility amt pd, Workers Comp (Imputed) | 
        CP Section (Edited) | 
     
    
        | ERFOR14X | 
        Facility amt pd, oth priv (Imputed) | 
        Constructed | 
     
    
        | ERFOU14X | 
        Facility amt pd, oth pub (Imputed) | 
        Constructed | 
     
    
        | ERFOT14X | 
        Facility amt pd, oth insur (Imputed) | 
        CP Section (Edited) | 
     
    
        | ERFXP14X | 
        Facility sum payments ERFSF14X – ERFOT14X | 
        Constructed | 
     
    
        | ERFTC14X | 
        Total facility charge (Imputed) | 
        CP Section (Edited) | 
     
 
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Imputed Physician Expenditure Variables
  
    
        | Variable | 
        Description | 
        Source | 
     
    
        | ERDSF14X | 
        Doctor amount paid, family (Imputed) | 
        Constructed | 
     
    
        | ERDMR14X | 
        Doctor amount pd, Medicare (Imputed) | 
        Constructed | 
     
    
        | ERDMD14X | 
        Doctor amount paid, Medicaid (Imputed) | 
        Constructed | 
     
    
        | ERDPV14X | 
        Doctor amt pd, priv insur (Imputed) | 
        Constructed | 
     
    
        | ERDVA14X | 
        Doctor amount paid, Veterans/CHAMPVA (Imputed) | 
        Constructed | 
     
    
        | ERDTR14X | 
        Doctor amount pd, TRICARE (Imputed) | 
        Constructed | 
     
    
        | ERDOF14X | 
        Doctor amt paid, oth federal (Imputed) | 
        Constructed | 
     
    
        | ERDSL14X | 
        Doctor amt pd, state/local gov (Imputed) | 
        Constructed | 
     
    
        | ERDWC14X | 
        Doctor amount pd, Workers Comp (Imputed) | 
        Constructed | 
     
    
        | ERDOR14X | 
        Doctor amt pd, oth private (Imputed) | 
        Constructed | 
     
    
        | ERDOU14X | 
        Doctor amt pd, oth pub (Imputed) | 
        Constructed | 
     
    
        | ERDOT14X | 
        Doctor amt pd, oth insur (Imputed) | 
        Constructed | 
     
    
        | ERDXP14X | 
        Doctor sum payments ERDSF14X – ERDOT14X | 
        Constructed | 
     
    
        | ERDTC14X | 
        Total doctor charge (Imputed) | 
        Constructed | 
     
    
        | IMPFLAG | 
        Imputation status | 
        Constructed | 
     
 
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Weights
  
    
        | Variable | 
        Description | 
        Source | 
     
    
        | PERWT14F | 
        Expenditure file person weight, 2014 | 
        Constructed | 
     
    
        | VARSTR | 
        Variance estimation stratum, 2014 | 
        Constructed | 
     
    
        | VARPSU | 
        Variance estimation PSU, 2014 | 
        Constructed | 
     
 
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