Inventory of Data Sources for Estimating Health Care Costs in the United States

Abstract

Objective

To develop an inventory of data sources for estimating health care costs in the United States and provide information to aid researchers in identifying appropriate data sources for their specific research questions.

Methods

We identified data sources for estimating health care costs using 3 approaches: (1) a review of the 18 articles included in this supplement, (2) an evaluation of websites of federal government agencies, non profit foundations, and related societies that support health care research or provide health care services, and (3) a systematic review of the recently published literature. Descriptive information was abstracted from each data source, including sponsor, website, lowest level of data aggregation, type of data source, population included, cross-sectional or longitudinal data capture, source of diagnosis information, and cost of obtaining the data source. Details about the cost elements available in each data source were also abstracted.

Results

We identified 88 data sources that can be used to estimate health care costs in the United States. Most data sources were sponsored by government agencies, national or nationally representative, and cross-sectional. About 40% were surveys, followed by administrative or linked administrative data, fee or cost schedules, discharges, and other types of data. Diagnosis information was available in most data sources through procedure or diagnosis codes, self-report, registry, or chart review. Cost elements included inpatient hospitalizations (42.0%), physician and other outpatient services (45.5%), outpatient pharmacy or laboratory (28.4%), out-of-pocket (22.7%), patient time and other direct nonmedical costs (35.2%), and wages (13.6%). About half were freely available for downloading or available for a nominal fee, and the cost of obtaining the remaining data sources varied by the scope of the project.

Conclusions

Available data sources vary in population included, type of data source, scope, and accessibility, and have different strengths and weaknesses for specific research questions.

Health care cost estimates are used to inform policy decisions on the setting of public and private budgets, structuring of insurance benefits and establishing reimbursement rates, and in cost-of-illness and cost-effectiveness analyses. In the United States, many sources of data are available for estimating health care use and costs. Prior reviews have identified some of these data sources^1,2 or summarized data sources used in cost-of-illness studies.^3,4 To build on these efforts, and aid analysts in the process of identifying and choosing data sources for estimating health care costs, we developed an inventory of data sources in the United States.

The majority of data sources commonly used to estimate health care costs in the United States were not originally developed for research purposes. Longitudinal information across the trajectory of illness is generally available only for the covered populations within discrete health insurance programs. National information is available from a variety of patient surveys and hospital discharge databases, but these data are generally cross-sectional, and may have small numbers of individuals with specific conditions. Several panel surveys collect information at multiple time points, but are of short duration or limited in clinical detail.^5,6 Because comprehensive longitudinal data for nationally representative populations across health insurance programs and without health insurance are largely unavailable, analysts must choose between different attributes of data sources for their specific study questions.

The choice of data source is important, because as illustrated in several articles in this issue, different data sources can produce different estimates of the cost of health care.^7,8 In addition, some existing data sources have rarely been used for estimating health care costs. For example, some costs, such as patient and caregiver time costs, are routinely excluded from cost-effectiveness analyses, even though they have long been recommended for inclusion,⁹ often in the mistaken belief that these data are not available. In the following sections, we describe our approach to identifying data sources for estimating health care costs, provide a summary of data source attributes, and include a series of tables with detailed information about the attributes of each data source. This information can serve as a resource for researchers choosing data sources for estimating health care costs.

IDENTIFICATION OF DATA SOURCES FOR ESTIMATING HEALTH CARE COSTS

We identified data sources for estimating health care costs in the United States using 3 approaches: (1) a review of the 18 articles included in this supplement,^{5,7,8,10–24} (2) an evaluation of websites of federal government agencies, nonprofit foundations, and related societies that support health care research or provide health care services, and (3) a systematic review of the recently published literature. Although health care utilization patterns from many data sources can be applied to standard fee schedules, we only considered data sources where direct medical or direct nonmedical health care costs are available or can be derived. We use the term “cost” to refer to payments, expenditures, reimbursements, charges, or prices.

Our review of federal government agency websites included the Agency for Healthcare Research and Quality, Bureau of Labor Statistics, the Centers for Disease Control (and the National Center for Health Statistics), the Centers for Medicare and Medicaid Services, the Department of Defense, the Federal Interagency Forum on Aging-Related Statistics, the Health Resources and Services Administration, the 27 individual Institutes and Centers of the National Institutes of Health, and the Veterans Health Administration. We also reviewed the websites of Academy Health, the Commonwealth Fund, the International Society for Pharmacoeconomics and Outcomes Research, the Kaiser Family Foundation, the Robert Wood Johnson Foundation, and the Research Data Assistance Center, a contractor to the Centers for Medicare and Medicaid Services that provides assistance to researchers interested in using Medicare or Medicaid data (http://www.resdac.umn.edu/).

To identify data sources from the published literature, we used Scopus, the largest abstract and citation database, including 15,000 peer-reviewed journals and 100% MEDLINE coverage (http://www.info.scopus.com/). We identified articles published in English between January 1990 and December 2007 that included the terms “cost,” “economic,” “expenditure,” “charge,” or “payment” in the title (N = 141,876), and used the search terms “data source” or “database” (N = 450,862 articles) and “healthcare” and (“cost” or “payment” or “charge”) or “health care” and (“cost” or “payment” or “charge”) for the full article (N = 37,946 articles). The combination of these searches yielded 539 articles.

The abstract for each article was reviewed to identify the data source(s) used to estimate health care costs, if possible. If the source could not be identified from the abstract, the entire article was reviewed. We excluded studies that met any of the following criteria: data source was from outside the United States, monetary estimates were not presented, data were not available after 1990, data were from a single institution or a clinical trial and unlikely to be widely available to other investigators, or the study was only available in the form of a published abstract or dissertation (N = 266). Because electronic searches may not identify all relevant studies,²⁵ we also evaluated all reviews (N = 107) to identify data sources used in the underlying research studies. The underlying research studies were evaluated further and the same eligibility criteria were applied. From the 3 search strategies, we identified a total of 88 data sources with sufficient information to abstract key data elements.

Because our goal was to provide information for analysts interested in using these data sources, we made extensive efforts to identify as many data sources and data elements as possible. Some data sources mentioned in the literature review could not be located. Others have been discontinued or merged with other data sources. In situations where we could not abstract the information about the population and cost elements from the data source website, we followed up with the listed contact for additional information. Despite these efforts, we did not have sufficient information about several data sources to include them in this inventory.

ABSTRACTION OF DATA SOURCE ATTRIBUTES

Information about each data source was abstracted using a standardized format. We abstracted descriptive information about the data source, including the sponsoring agency or organization (government, private, university), website for the data source, lowest level of data aggregation (hospital or provider, service, and individual or patient), and type of data source (survey, administrative or linked administrative data, discharge, fee or cost schedule).

We also abstracted information about the eligible or covered population, whether the data were nationally representative, whether they were cross-sectional or longitudinal (including repeated cross-sections or panels), and the source of diagnosis information (procedure or diagnosis codes, self-report, chart or medical record, registry, not available). Cost elements abstracted were the types of services or resources for which cost data were collected, including institution or facility (eg, hospital or freestanding clinic), inpatient hospitalization, physician and other outpatient, outpatient pharmacy or laboratory, out-of-pocket, wages, patient time, and other direct nonmedical (eg, disability days). The cost of obtaining the data source was categorized as either (1) freely available for download/less than $100 or (2) cost depends on scope of project. We did not gather information about data completeness or quality.

ATTRIBUTES OF DATA SOURCES FOR ESTIMATING HEALTH CARE COSTS

Descriptive characteristics of the data sources we identified are summarized in Table 1 and listed for individual data sources in the remaining Tables. The lowest level of data aggregation for most sources was the individual or patient-level, followed by the service level, and hospital, provider, or institution level. Two data sources were aggregated at the national level.^23,26 Data sources at the service level of aggregation included hospital and other discharges, fee or cost schedules for physician services, ambulatory services, and equipment or prescriptions. Government agencies sponsored the majority of the data sources. Most data sources were national or nationally representative. A sizable portion were surveys, followed by administrative data or survey or registry linked to administrative data, fee or cost schedules, hospital discharges, and other types of data. Over 60% of the data sources were cross-sectional. The remaining data sources were longitudinal, including panel data with repeated cross-sections. Many of the data sources provided information about diagnosis with specific diseases, including procedure or diagnosis codes that can be used with algorithms to identify patients with disease, self-reported diagnoses, and registry or chart review identified diagnoses.

TABLE 1.

Characteristics of Data Sources for Estimating Direct Medical and Nonmedical Health Care Costs

	Data Sources
	Number (N = 88)	%
Lowest level of data aggregation
National	2	2.3
Hospital/provider	12	13.6
Service	22	25.0
Individual/patient	52	59.1
Sponsor*
Government agency	60	68.2
Private (for profit and not-for profit)	34	38.6
University	4	4.5
Population
National or nationally representative	64	72.7
Multistate	16	18.2
Other	8	9.1
Type of data source
Survey	37	42.0
Administrative data or linked administrative data	25	28.4
Discharge	5	5.7
Fee or cost schedule	14	15.9
Other	7	8.0
Length of observation
Cross-sectional (or single observation)	55	62.5
Longitudinal	33	37.5
Source of diagnosis information*
Procedure, diagnosis or DRG codes	40	45.5
Self-report	18	20.5
Registry	6	6.8
Chart or medical review	6	6.8
Other	3	3.4
Not available	29	33.0
Cost elements*
Institution or facility	5	5.7
Inpatient hospitalization	37	42.0
Physician and other outpatient	40	45.5
Outpatient pharmacy or laboratory	25	28.4
Out-of-pocket	20	22.7
Patient time and other direct nonmedical	31	35.2
Wages	12	13.6
Cost of data
Freely available for downloading/less than $100	43	48.9
Cost varies with scope of project	45	51.1

^*Percentages add to more than 100%.

The cost elements available in the different data sources included inpatient hospitalization (42.0%), institution or facility (5.7%), physician and other outpatient (45.5%), outpatient pharmacy or laboratory (28.4%), out-of-pocket (22.7%), patient time and other direct nonmedical costs (35.2%), and provider wages (13.6%). About half of the data sources were freely downloadable or available for a nominal fee (ie, <$100), and the cost of acquiring data varied with the scope of the project for the other half.

We classified data sources by level of data aggregation and type of data and listed the available cost elements and source of diagnosis information in Tables 2 to 6. Data sources whose lowest level of data aggregation was at the hospital and provider level are listed in Table 2. Available cost elements include institution or facility, inpatient hospitalization, and wages or payroll. Data sources with the lowest level of data aggregation at the service level include discharges and cost, price, or fee schedules (Table 3). Available cost elements include inpatient hospitalization, outpatient services, and pharmacy and equipment.

TABLE 2.

Hospital and Provider Level Data Sources Used to Estimate Direct Medical Health Care Costs

Data Source	Description	Diagnosis Information Available	Cost Elements
			Institution or Facility	Inpatient Hospitalization	Wages/Payroll
American Hospital Association    Annual Survey (AHA)	Annual survey of more than 6000 hospitals with information on organizational    structure, facilities and services, utilization, managed care relationships,    staffing, and expenses		√		√
American Hospital Directory    (AHD)	Database of 6000 hospitals with information from both public and private    sources including Medicare claims data, hospital cost reports, and other files    obtained from the CMS	√, DRG codes	√	√
Area Resource File (ARF)	Contains information on facilities, health professions, economic activity, and    socioeconomic characteristics for each of the nation’s counties. Hospital information    includes overall expenditures and Medicare reimbursements		√		√
Community Health Workers    (CHW) National Workforce    Study	Survey of CHW employers in all 50 states and in-depth interviews of    employers and CHWs in 4 states to make national and state workforce    estimates. CHW wages are reported				√
Current Employment Statistics    (CES)	Each month the CES program surveys about 150,000 businesses and    government agencies to provide detailed industry data on employment,    hours, and average hourly and weekly earnings of workers on nonfarm    payrolls				√
Medical Group Management    Association (MGMA),    Physician Compensation    and Production survey	Annual survey of MGMA membership of physicians, group practices, and    specialties to obtain physician compensation and production data, including    starting salaries by specialty and professional charges, gross charges, and    total and physician work relative units				√
Medicare Cost Reports	Contains provider information such as facility characteristics, utilization data,    cost and charges by cost center (total and for Medicare),    Medicare settlement data, and financial statement data. Includes cost reports for    hospital, skilled nursing facility, home health agency, renal facility, and    hospice		√
National Association of    Psychiatric Health Systems    (NAPHS) Annual Survey	Survey includes information on behavioral health care delivery, including    trend analysis in hospitals and residential treatment centers and cost items    such as average net revenue per inpatient hospitalization and total net    revenue by residential treatment center		√	√
National Compensation Survey    (NCS)	Comprehensive measures of occupational earnings and wage, employment    cost trends, and detailed benefit provisions based on visits to    establishments. Detailed occupational earnings are available for    metropolitan and nonmetropolitan areas, and nationally				√
National Sample Survey of    Registered Nurses (NSSRN)	Survey of registered nurses in the workforce about education and training,    current and recent workforce participation, and income				√
Occupational Employment    Statistics (OES) Survey	Employment and wage estimates for over 800 occupations, including mean    and median hourly wages for physicians and surgeons, registered nurses,    and other health professionals. Available nationally, for states, and    metropolitan areas				√
Quarterly Census of    Employment and Wages    (QCEW)	Quarterly count of employment and wages reported by employers covering    98% of US jobs. Files include data on the number of establishments,     monthly employment, and quarterly wages, by industry, county, and sector				√

TABLE 6.

Individual Level Data Sources Used to Estimate Patient and Caregiver Time

Data Source	Population	Diagnosis Information Available	Time Cost Element
			Nursing Home Stays in Days	Time in Outpatient Care	Restricted Activity Days	Time in Home Care/ Home Therapy	Hospice Care
American Cancer    Society’s Quality of    Life Survey for    Caregivers*	Panel survey of family caregivers of cancer patients identified through    registries. Includes information on patient and caregiver characteristics,    and average weekly hours spent caregiving. Data collected by mailed    survey	√, registry (cancer)
American Time Use    Survey (ATUS)	US civilian noninstitutionalized persons aged 15 and older in households    that completed their 8th interview for the Current Population Survey.    Data are collected through telephone interviews			√		√
Cancer of the Prostate    Strategic Urologic    Research Endeavor    (CaPSURE)	Longitudinal study of prostate cancer patients in community practice.    Physicians provide clinical assessment of patients during treatment,    including method of diagnosis, and results of all procedures and lab tests	√, chart or medical    record	√		√	√	√
Medicare Current    Beneficiary Survey    (MCBS)	Nationally representative sample of aged, disabled, and institutionalized    Medicare beneficiaries	√, self-report, chart,    and procedure or    diagnosis codes		√		√	√
Medicare Health    Outcomes Survey    (HOS)	National survey of a random sample of Medicare beneficiaries continuously    enrolled for 6 mo or longer in managed care health plans. All plans with    Medicare Advantage contracts participate	√, self-report			√
Midlife Development    in the United States    Survey (MIDUS)	Series of national surveys of adults in midlife. Also surveys of siblings of    the general population respondents, and a twin pairs sample	√, self-report			√
National Ambulatory    Medical Care    Survey (NAMCS)	Sampled visits to US nonfederal office-based physicians primarily engaged    in direct patient care. Data are recorded by physicians and staff	√, chart or medical    record		√
National Caregiver    Survey*	National survey of caregivers providing one or more Activities of Daily    Living (ADL) or Instrumental ADLs for someone aged 18 or older.    Includes weekly hours spent caregiving. Data collected by telephone    interview	√, self-report
National Comorbidity    Survey (NCS)	The NCS was originally fielded in 1990–1992, and is a nationally    representative mental health survey in the US with diagnostic interviews.    Respondents were reinterviewed in 2001–2002	√, self-report			√
National Health    Interview Survey    (NHIS) (Core)	Nationally representative sample of US civilian noninstitutionalized    population. Data are collected via a personal household interview	√, self-report			√
NHIS (1992 Cancer    control supplement)	Nationally representative sample of US civilian noninstitutionalized adults    aged 18 or older. Data are collected via a personal household interview	√, self-report		√
NHIS (1994–1995    Disability Phase I    supplement)	Nationally representative sample of US civilian noninstitutionalized    children. Questions about home therapy time only for children. Data are    collected via a personal household interview	√, self-report				√
National Home and    Hospice Care    Survey (NHHCS)	National sample of home health agencies and hospices and their current and    discharged patients. Data are collected by administrators and through    personal interviews with staff	√, chart or medical    record				√	√
National Hospital    Ambulatory    Medical Care    Survey (NHAMCS)	National sample of visits to emergency and outpatient departments of    nonfederal general and short-stay hospitals.    Data are collected by hospital staff	√, chart or medical    record		√
National Mortality    Followback Survey    (NMFS)	National sample of death certificates for individuals aged 15 yr and over    who were residing and died in the United States. Survey is completed by    next of kin or another person familiar with the decedent’s life history	√, proxy report	√		√
National Nursing    Home Survey    (NNHS)	Nationally representative sample of US nursing homes, and their services,    staff, and residents. Data are collected through surveys of nursing    assistants and personal interviews.	√, chart or medical    record	√
National Survey of    Ambulatory Surgery    (NSAS)	Ambulatory surgery cases from a nationally representative sample of    nonfederal hospital-based and freestanding ambulatory surgery centers	√, chart or medical    record		√

Information on length of hospital stay available from hospital discharge data listed in Table 3 and administrative data with inpatient information listed in Table 4.

^*Data collected as the total amount of time spent providing patient care and specific elements not available separately.

TABLE 3.

Service Level Data Sources Used to Estimate Direct Medical Health Care Costs

Data Source	Description	Diagnosis Information Available	Cost Elements
			Inpatient Hospitalization	Outpatient Services	Pharmacy and Equipment
Alere databases	Discharge planning tool	√, DRG codes	√
Centers for Disease Control and    Prevention (CDC) Vaccine    Price List	Provides current vaccine contract prices and private sector prices reported by vaccine    manufacturers				√
Chain Pharmacy Industry Profile	Contains statistics on operational performance of retail pharmacies and average    prescription prices by state and source of payment				√
First DataBank National Drug    Data File (NDDF)	Contains descriptive and pricing information for medications approved by the FDA,    and commonly-used over-the-counter and alternative therapy agents				√
Healthcare Costs and Utilization    Program (HCUP)-Nationwide    Inpatient Sample (NIS)	The largest all-payer inpatient care database with all discharge data from sampled    hospitals. Includes diagnoses, procedures, admission and discharge status, patient    demographics, expected payment source, total charges, length of stay, and hospital    characteristics	√, procedure or    diagnosis codes	√
HCUP Kids’ Inpatient Database    (KID)	The only all-payer inpatient care database for children. Includes diagnoses,    procedures, admission and discharge status, patient demographics, expected    payment source, total charges, length of stay, and hospital characteristics	√, procedure or    diagnosis codes	√
HCUP State Ambulatory Surgery    Databases (SASD)	Contains ambulatory surgery encounter abstracts in participating states. All databases    include abstracts from hospital-affiliated ambulatory surgery sites and some    contain the universe of ambulatory surgery abstracts for that state. Includes    diagnoses, procedures, discharge status, patient demographics, expected payment    source, total charges, and hospital identifiers	√, procedure or    diagnosis codes		√
HCUP State Emergency    Department Databases (SEDD)	Captures discharge information on all emergency department visits in participating    states that do not result in an admission. Includes diagnoses, procedures, patient    demographics, expected payment source, total charges, and hospital identifiers	√, procedure or    diagnosis codes		√
HCUP State Inpatient Databases    (SID)	Contains the universe of inpatient discharge abstracts in participating states, about    90% of all US community hospital discharges. Includes diagnoses, procedures,    admission and discharge status, patient demographics, expected payment source,    total charges, length of stay, and hospital characteristics	√, procedure or    diagnosis codes	√
Medicare Ambulance Fee    Schedule	All ambulance services, including volunteer, municipal, private, and institutional    providers, ie, hospitals, critical access hospitals, and skilled nursing facilities			√
Medicare Ambulatory Payment    Classifications (APC)	Part of the OPPS. Services in each APC are similar clinically and in terms of the    resources they require. Depending on the services provided, hospitals may be paid    for more than one APC for an encounter			√
Medicare Clinical Laboratory Fee    Schedule	Covers outpatient clinical laboratory services which are paid based on the lesser of    the amount billed, the local fee for a geographic area, or a national limit			√
Medicare Diagnosis Related    Group (DRG) Fee Schedule	Developed as part of the Medicare prospective payment system to classify hospital    cases into one of approximately 500 groups, expected to have similar hospital    resource use. DRGs are assigned by a “grouper” program based on ICD    diagnoses, procedures, age, sex, and the presence of complications or    comorbidities	√, DRG codes	√
Medicare Durable Medical    Equipment,    Prosthetics/Orthotics Supplies    Fee Schedule	Medicare payment for durable medical equipment, prosthetics and orthotics,    parenteral and enteral nutrition, surgical dressings, and therapeutic shoes and    inserts				√
Medicare Hospital Outpatient    Prospective Payment System    (OPPS) File	Medicare file contains select claim level data and is derived from hospital outpatient    prospective payment system claims	√, procedure or    diagnosis codes		√
Medicare Physician Fee Schedule	Medicare payments for physician and nonphysician services developed with    estimates of total practice expenses that physicians in each specialty incur and of    resources required to perform each of the individual services in each specialty		√	√
Medispan Drug Database	Databases contain drug product and pricing information and clinical decision support    databases that identify drug conflicts				√
Physicians’ Desk Reference-Red    Book	Provides prices on prescription drugs, OTC items and reimbursable medical supplies,    including average wholesale prices, direct prices, and federal upper limit prices for    prescription drugs; and suggested retail prices for OTC products				√
State Medicaid prescription    reimbursement information	Reports reimbursement methodologies, dispensing fees, and co-payment amounts    utilized by state Medicaid programs				√
WisdomKing.com	Lists prices for physical therapy supplies, physical therapy equipment, and    rehabilitation products				√

Data sources at the individual or patient-level that are surveys and administrative data or administrative data linked to surveys or registries are listed in Table 4 and Table 5, respectively. Detailed cost elements for these patient-level data included inpatient hospitalization, physician or other outpatient services, outpatient pharmacy, out-of-pocket, and other direct nonmedical. Individual level data sources that can be used to estimate patient or caregiver time are listed in Table 6. Time information abstracted included nursing home stays, outpatient services, restricted activity days, home care/ home therapy, and hospice care. Information on length of inpatient hospital stay was available from hospital discharge data listed in Table 3 and administrative data with inpatient information listed in Table 4, and not listed separately in Table 6.

TABLE 4.

Individual or Patient Level Data Sources Used to Estimate Direct Medical Health Care Costs: Surveys

Data Source	Population	Diagnosis Information Available	Cost Elements
			Inpatient Hospitalization	Physician and Other Outpatient Services	Outpatient Pharmacy	Out-of- Pocket	Nonmedical
Alcohol and Drag Services    Study	Nationally representative sample of substance abuse treatment    facilities and clients in the US. Data were collected    through telephone interviews, records reviews, and follow-    up personal interviews	√, procedure or    diagnosis codes	√	√			√
Community Tracking Survey    (Household Component)	Nationally representative sample of the civilian,    noninstitutionalized population. The survey is conducted by    telephone					√	√
Consumer Expenditure    Survey (CES)	Nationally representative sample of civilian,    noninstitutionalized consumer units (eg, households).    Information is obtained through a quarterly personal    interview and weekly diaries	√, self-report				√
Consumerism in Health    Survey	Sample of privately insured adults ages 21–64. Information    was obtained through an internet survey					√
Current Population Survey    (CPS)	Nationally representative sample of the civilian,    noninstitutionalized population over 16 yr of age. Data are    collected by personal and telephone interviews						√
HIVnet	Data from 12 medical practices located across the US with    14,000 HIV patients	√, procedure or    diagnosis codes	√	√
Kaiser Women’s Health    Study	Nationally representative sample of civilian,    noninstitutionalized women ages 18 to 64. The survey was    conducted via telephone interview	√, self-report				√
Medical Expenditure Panel    Survey, Household and    Provider Components    (MEPS)	Nationally representative sample of the US    noninstitutionalized population. Survey data were collected    through personal interviews. MEPS also collects data from    medical providers which supplements and/or replaces    information received from the household respondents about    the health care that was provided to the sampled household    members	√, self-report and    chart or medical    record	√	√	√	√	√
National Health and    Wellness Survey	Representative of the general population of adults aged 18 +    in the US, European Union, and Asia		√	√	√	√	√
National Health Interview    Survey (NHIS) (Core)	Nationally representative sample of US civilian    noninstitutionalized population. Data are collected via a    personal household interview					√
National Home and Hospice    Care Survey (NHHCS)	Nationally representative sample of the US civilian,    noninstitutionalized population obtaining services from a    home or hospice care agency licensed or certified by    Medicare or Medicaid. Data are collected through personal    interviews with administrators and staff	√, chart or    medical record		√			√
National Long Term Care    Survey (NLTCS)	Nationally representative sample of the elderly population    (65 yr or older) enrolled in Medicare, who are living in the    community or institutions. Data are collected through    personal interviews	√, proxy report	√	√			√
National Mortality    Followback Survey    (NMFS)	National sample of death certificates for individuals aged 15    yr and over who were residing and died in the US. Survey    is completed by next of kin or another person familiar with    the decedent’s life history	√, proxy report				√	√
National Nursing Home    Survey (NNHS)	Nationally representative sample of the US civilian,    noninstitutionalized population obtaining services from a    nursing home certified by Medicare or Medicaid, or having    a state license to operate as a nursing home. Data is    obtained through interviews	√, chart or    medical record		√		√	√
National Survey of    Ambulatory Surgery    (NSAS)	Survey of patients scheduled for surgical and nonsurgical    procedures performed in hospital-based and freestanding    ambulatory surgery centers	√, chart or    medical record		√			√
National Survey of    America’s Families    (NSAF)	Nationally representative sample of the civilian,    noninstitutionalized population under the age of 65. The    survey is conducted by telephone interviews					√
Panel Study of Income    Dynamics (PSID)	Nationally representative sample of civilian,    noninstitutionalized individuals, and the family units in    which they reside. Information was obtained via telephone    interviews with computer-based instruments	√, self-report				√	√
Survey of Income and    Program Participation    (SIPP)	Nationally representative sample of households in the US    civilian, noninstitutionalized population. Information is    obtained via in-person interviews					√	√

TABLE 5.

Individual Level Data Sources Used to Estimate Direct Medical Health Care Costs: Administrative Data, and Registries and Surveys Linked to Administrative Data

Data Source	Population	Diagnosis Information Available	Cost Elements
			Inpatient Hospitalization	Physician and Other Outpatient Services	Outpatient Pharmacy	Out-of Pocket	Nonmedical
Alere databases	Information management system with administrative    data	√, procedure or diagnosis    codes	√	√	√
Blue Cross/Blue Shield	Enrollees in 39 independent and locally operated    health plans	√, procedure or diagnosis    codes	√	√	√
Cancer Research Network (CRN)*	Cancer and noncancer patients receiving care in a    consortium of 14 nonprofit research centers in    integrated health care delivery organizations across    the nation	√, registry (cancer) and    procedure or diagnosis    codes	√	√	√
Health and Retirement Survey    (HRS)-Medicare†	Total civilian noninstitutionalized population age 50    and older who were enrolled in Medicare and    provided personal identification data	√, self-report and procedure    or diagnosis codes	√	√	‡
Health Maintenance Organization    Research Network (HMORN)	Patients receiving care from any of 15 HMOs with    formal recognized research capacities	√, procedure or diagnosis    codes	√	√	√
Human Capital Management    Services (HCMS)	Individuals enrolled in employer-sponsored insurance.    Also includes information on sick leave, disability,    and productivity	√, procedure or diagnosis    codes	√	√	√	√	√
IMS health plan data	Enrollees in 97 health plans nationwide	√, procedure or diagnosis    codes	√	√	√	√
Ingenix	Enrollees in large geographically diverse health    insurance plan	√, procedure or diagnosis    codes	√	√	√
MarketScan databases	Large national claims and encounters data for    individuals enrolled in employer-sponsored    commercially insured and Medicare supplemental    insurance. Subsets of patients may be linked to    short-term disability and absenteeism data	√, procedure or diagnosis    codes	√	√	√	√	√
Medicaid	Enrollees in state-based program available only to    medically needy, categorically needy or special    groups. Eligibility varies state to    state and group to group	√, procedure or diagnosis    codes	√	√	√
Medicare	Beneficiaries in Medicare program with fee-for-    service coverage aged ≥65 yr, <65 yr with certain    disabilities, or all ages with End-Stage Renal    Disease (ESRD)	√, procedure or diagnosis    codes	√	√	‡
Medicare Current Beneficiary    Survey (MCBS)†	Nationally representative sample of aged, disabled,    and institutionalized Medicare beneficiaries	√, self-report, chart, and    procedure or diagnosis    codes	√	√	√‡	√	√
MediQual/Cardinal Health Atlas    System	Information management system with clinical and    administrative data	√, procedure or diagnosis    codes	√	√
MedMining, a Geisinger Health    System business	Patients of all ages in an integrated, health care    system spanning 40 counties in Pennsylvania	√, procedure or diagnosis    codes	√	√	√	√	√
National Health and Nutrition    Examination Survey (NHANES) –    Medicare†	National sample of civilian noninstitutionalized    participants in NHANES who were enrolled in    Medicare and provided personal identification data    to NCHS	√, examination and procedure    or diagnosis codes	√	√	‡		√
National Health Interview Survey    (NHIS)-Medicare†	National sample of civilian noninstitutionalized    respondents to the NHIS who were enrolled in    Medicare and provided personal identification data    to NCHS	√, self-report and procedure    or diagnosis codes	√	√	‡		√
National Long Term Care Survey    (NLTCS)–Medicare†	Nationally representative sample of the elderly    population ≥65 yr enrolled in Medicare, living in    the community or institutions. Data are collected    through personal interviews	√, self-report and procedure    or diagnosis codes	√	√	‡		√
New Beneficiary Data System-    Medicare†	Sample of Social Security beneficiaries who were    retired or disabled workers, or other aged (ie, wife    or widow) with 10-yr follow-up	√, procedure or diagnosis    codes	√	√	‡
PharMetrics (Integrated Medical    and Pharmaceutical Database)	Patients from over 90 health plans across the US with    multiple product types (eg, HMO, PPO), payor    types (eg, commercial, self-pay), provider    specialty, and start and stop dates for plan    enrollment.	√, procedure or diagnosis    codes	√	√	√	√
Premier Perspective Database	Provides drug utilization, inpatient discharges, and    hospital outpatient visits from acute care facilities,    ambulatory surgery centers and clinics	√, procedure or diagnosis    codes	√	√	√	√
Surveillance, Epidemiology and    End-Results (SEER)–Medicare*	Cancer patients and noncancer patients in a SEER    region who are enrolled in Medicare fee-for-service    ≥65 yr, <65 yr with certain disabilities, or any    age with End-Stage Renal Disease (ESRD)	√, registry (cancer) and    procedure or diagnosis    codes	√	√	†
The Second Longitudinal Study of    Aging (LSOA II)–Medicare†	Total civilian noninstitutionalized population ≥70 yr    in LSOA enrolled in Medicare and provided    personal identification data to NCHS	√, self-report and procedure    or diagnosis codes	√	√	‡
United Healthcare	Enrollees in large health insurance company	√, procedure or diagnosis    codes	√	√	√
United States Renal Data System    (USRDS)*	All end-stage renal disease (ESRD) patients eligible    for Medicare. Includes data from CMS with other    databases	√, registry (ESRD) and    procedure or diagnosis    codes	√	√	‡
Veterans Affairs (VA) National    Prosthetic Patient Database    (NPPD)*	Recipients of prosthetic, orthotic, and sensory aids    from the Veterans Health Administration	√, registry and procedure or    diagnosis codes		√
Veterans Affairs (VA) Decision    Support System and Health    Economics Resource Center    (HERC) average cost databases	Recipients of care from the Veterans Health    Administration	√, procedure or diagnosis    codes	√	√	√

^*Data source is registry linked to administrative data.

^†Data source is survey linked to administrative data.

^‡Data on Medicare part D prescription drug services for 2006 will be available starting in 2009. Before 2006, drugs administered parenterally and their administration was covered by Medicare part B, as were Prodrugs, the oral drug equivalent of drugs administered parenterally.

Finally, an alphabetical listing of all data sources with the web address for additional information, and the Table(s) where the data source is described in greater detail is contained in Table 7. Table 7 also includes indicators of whether data were nationally representative and whether longitudinal data were available, and the cost of obtaining the data. Use of several data sources requires collaboration with internal investigators; these data sources are indicated with a footnote. Data sources aggregated at the national level were not abstracted or reported separately, although they are listed in Table 7.

TABLE 7.

Alphabetical Listing of Data Sources for Estimating Health Care Costs

Data Source	Website	Appendix Table	Nationally Representative	Longitudinal Data Available	Cost of Data Source
					Free Download; or <$100	Depends on Scope of Project; ≥$100
Alcohol and Drug Services Study	oas.samhsa.gov/adss.htm	4	√		√
Alere databases	www.matria.com	5				√
American Cancer Society’s Quality of    Life Survey for Caregivers	www.cancer.org/docroot/RES/content/RES_9_l_BRC_Survivorship_Research.asp	6		√, Panel		√*
American Hospital Association (AHA)    Annual Survey	www.ahadata.com/ahadata_app/index.jsp	2	√			√
American Hospital Directory	www.ahd.com/	2	√			√
American Time Use Survey (ATUS)	www.bls.gov/tus/	6	√		√
Area Resource File (ARF)	www.arfsys.com/overview.htm	2	√			√
Blue Cross/Blue Shield	www.bcbs.com/coverage/find/plan/	5		√		√
Cancer of the Prostate Strategic    Urologic Research Endeavor    (CaPSURE)	urology.ucsf.edu/capsure/overview.htm	6		√		√
Cancer Research Network (CRN)	crn.cancer.gov/	5		√		√*
Centers for Disease Control and    Prevention (CDC) Vaccine Price List	www.cdc.gov/vaccines/programs/vfc/cdc-vac-price-list.htm	3	√		√
Chain Pharmacy Industry Profile	www.nacds.org/wmspage.cfm?parm1=605	3	√			√
Community Health Workers National    Workforce Study	bhpr.hrsa.gov/healthworkforce/chw/	2	√		√
Community Tracking Survey    (Household Component)	www.hschange.com/index.cgi?data=12	4	√		√
Consumer Expenditure Survey (CES)	www.bls.gov/cex/home.htm	4	√		√
Consumerism in Health Survey	www.commonwealthfund.org/surveys/surveys_show.htm?doc_id=673681	4			√
Current Employment Statistics (CES)	www.bls.gov/ces/	2	√		√
Current Population Survey (CPS)	www.bls.gov/cps/	4	√		√
First DataBank National Drug Data File    (NDDF)	www.firstdatabank.com/products/nddf/	3	√			√
Healthcare Cost and Utilization Project    (HCUP) Kids’ Inpatient Database    (KID)	www.hcup-us.ahrq.gov/kidoverview.jsp	3				√
HCUP Nationwide Inpatient Sample    (NIS)	www.hcup-us.ahrq.gov/nisoverview.jsp	3	√			√
HCUP State Ambulatory Surgery    Databases (SASD)	www.hcup-us.ahrq.gov/sasdoverview.jsp	3				√
HCUP State Emergency Department    Databases (SEDD)	www.hcup-us.ahrq.gov/seddoverview.jsp	3				√
HCUP State Inpatient Databases (SID)	www.hcup-us.ahrq.gov/sidoverview.jsp	3				√
Health and Retirement Survey (HRS)-    Medicare	hrsonline.isr.umich.edu/rda/medicare.htm	5	√	√		√
Health Maintenance Organization    Research Network (HMORN)	www.hmoresearchnetwork.org/about.htm	5		√		√
HIVnet	www.ahrq.gov/data/hivnet.htm	4	√		√
Human Capital Management Services    (HCMS)	www.hcmsgroup.com/hcms/default.aspx	5		√		√
IMS health plan data	www.imshealth.com/portal/site/imshealth	5	√	√		√
Ingenix	www.ingenix.com/	5		√		√
Kaiser Women’s Health Study	www.kff.org/womenshealth/whp070705pkg.cfm	4	√		√
MarketScan Databases	www.medstatmarketscan.com	5		√		√
Medicaid	www.cms.hhs.gov/MedicaidDataSourcesGenInfo/02_MSISData.asp	5		√		√
Medical Expenditure Panel Survey,    Household and Provider Components    (MEPS)	www.meps.ahrq.gov/mepsweb/	4	√	√, panel	√
Medical Group Management    Association (MGMA), Physician    Compensation and Production Survey	www5.mgma.com/ecom/Default.aspx?tabid=138&action=INVProductDetails&args=3823&kc=PHY08WE00; http://www.mgma.com/	2				√
Medicare	www.cms.hhs.gov/FilesForOrderGenInfo/	5	√	√		√
Medicare Ambulance Fee Schedule	www.cms.hhs.gov/ambulancefeeschedule/	3	√		√
Medicare Ambulatory Payment    Classification (APC)	www.cms.hhs.gov/HospitalOutpatientPPS/	3	√		√
Medicare Clinical Laboratory Fee    Schedule	www.cms.hhs.gov/ClinicalLabFeeSched/	3	√		√
Medicare Cost Reports	www.cms.hhs.gov/CostReports/	2	√		√
Medicare Current Beneficiary Survey    (MCBS)	www.cms.hhs.gov/MCBS/	5, 6	√	√		√
Medicare Diagnosis Related Group    (DRG) Fee Schedule	www.cms.hhs.gov/acuteinpatientpps/	3	√		√
Medicare Durable Medical Equipment,    Prosthetics/Orthotics & Supplies Fee    Schedules	www.cms.hhs.gov/DMEPOSFeeSched/LSDMEPOSFEE/List.asp	3	√		√
Medicare Health Outcomes Survey    (HOS)	www.hosonline.org/	6	√	√, panel	√
Medicare Hospital Outpatient    Prospective Payment System (OPPS)    File	www.cms.hhs.gov/IdentifiableDataFiles/03_HospitalOPPS.asp	3	√			√
Medicare Physician Fee Schedule	www.cms.hhs.gov/PhysicianFeeSched/	3	√
MediQual/Cardinal Health Atlas System	www.mediqual.com/products/atlas.asp	5		√	√	√
Medispan Drug Database	www.medispan.com/drug-database.aspx	3	√			√
MedMining, a Geisinger Health System    business	www.medmining.com	5		√	√	√
Midlife Development in the United    States Survey (MIDUS)	midmac.med.harvard.edu/research.html	6	√	√, panel	√
National Ambulatory Medical Care    Survey (NAMCS)	www.cdc.gov/nchs/about/major/ahcd/ahcd1.htm	6	√		√
National Association of Psychiatric    Health Systems (NAPHS) Annual    Survey	www.naphs.org/	2			√
National Caregiver Survey	www.caregiving.org/data/04finalreport.pdfv	6	√			√
National Comorbidity Survey	www.hcp.med.harvard.edu/ncs/	6	√	√, panel	√
National Compensation Survey (NCS)	www.bls.gov/NCS/	2	√		√
National Health and Nutrition    Examination Survey (NHANES)–    Medicare	www.cdc.gov/nchs/nhanes.htm	5	√	√		√
National Health and Wellness Survey	www.nhwsurvey.com	4	√			√
National Health Expenditure Accounts    (NHEA)	www.cms.hhs.gov/NationalHealthExpendData/Downloads/tables_.pdf	†	√		√
National Health Interview Survey    (NHIS) (Core)	www.cdc.gov/nchs/nhis.htm	4, 6	√		√
NHIS, 1992 Cancer control supplement	www.cdc.gov/nchs/nhis.htm	6	√		√
NHIS, 1994–1995 Disability Phase I    supplement	www.cdc.gov/nchs/nhis.htm	6	√		√
National Health Interview Survey    (NHIS)–Medicare	www.cdc.gov/nchs/nhis.htm	5	√	√		√
National Home and Hospice Care    Survey (NHHCS)	www.cdc.gov/nchs/nhhcs.htm	4, 6	√		√
National Hospital Ambulatory Medical    Care Survey (NHAMCS)	www.cdc.gov/nchs/about/major/ahcd/ahcd1.htm	6	√		√
National Long Term Care Survey    (NLTCS)	www.nltcs.aas.duke.edu/index.htm	4	√	√	√
National Long Term Care Survey    (NLTCS)–Medicare	www.nltcs.aas.duke.edu/data.htm	5	√	√		√
National Mortality Followback Survey    (NMFS)	www.cdc.gov/nchs/about/major/nmfs/nmfs.htm	4, 6	√		√
National Nursing Home Survey    (NNHS)	www.cdc.gov/nchs/nnhs.htm	4, 6	√		√
National Sample Survey of Registered    Nurses (NSSRN)	datawarehouse.hrsa.gov/NSSRN.htm	2	√		√
National Survey of Ambulatory Surgery    (NSAS)	www.cdc.gov/nchs/about/major/hdasd/nhds.htm	4, 6	√		√
National Survey of America’s Families    (NSAF)	www.rwjf.org/pr/product.jsp?id=29617	4	√		√
New Beneficiary Data System-Medicare    (NBDS)–Medicare	www.ssa.gov/policy/docs/microdata/nbds/index.html	5	√	√		√
Occupational Employment Statistics    (OES) Survey	www.bls.gov/oes/	2	√		√
Organization for Economic Cooperation    and Development (OECD) health    data	www.oecd.org/statisticsdata/0,3381,en_2649_34631_1_119656_1_1_1,00.html	†	√		√
Panel Study of Income Dynamics    (PSID)	psidonline.isr.umich.edu/	4	√	√, panel	√
PharMetrics (Integrated Medical and    Pharmaceutical Database)	www.pharmetrics.com	5		√		√
Physicians’ Desk Reference-Red Book	www.micromedex.com/products/redbook/	3	√			√
Premier Perspective Database	www.premierinc.com/prs/	5		√		√
Quarterly Census of Employment and    Wages (QCEW)	www.bls.gov/cew/	2	√		√
State Medicaid Prescription    Reimbursement Information	www.cms.hhs.gov/Reimbursement/20_StateMedicaidRxReimb.asp	3			√
Surveillance, Epidemiology and End-    Results (SEER)-Medicare	healthservices.cancer.gov/seermedicare/	5	√	√		√
Survey of Income and Program    Participation (SIPP)	www.census.gov/sipp/	4	√	√, panel		√
The Second Longitudinal Study of    Aging (LSOA II)-Medicare	www.cdc.gov/nchs/about/otheract/aging/lsoa2.htm	5		√		√
United Healthcare	www.uhc.com/	5	√	√		√
United States Renal Data System    (USRDS)	www.usrds.org/	5	√	√		√
Veterans Affairs (VA) Decision Support    System and HERC average cost    databases	www.herc.research.va.gov	5	√	√	√*
Veterans Affairs (VA) National    Prosthetic Patient Database (NPPD)	www.virec.research.va.gov	5	√		√*
WisdomKing.com	www.wisdomking.com/	3	√		√

^*Use of data requires collaboration with internal investigators.

^†Data available only at the national level and not abstracted separately.

SUMMARY

In this inventory, we identified more than 80 data sources in the United States that can be used to estimate health care costs, and abstracted key characteristics, including sponsor, lowest level of data aggregation, population included, length of observation, source of diagnosis information, and available cost elements. The data sources we identified vary in these dimensions as well as in their accessibility. Some are publicly available and freely downloadable directly from sponsors’ websites, others must be purchased, and still others are restricted to the use of researchers or collaborators within sponsors’ institutions.

The inventory is as comprehensive as we could make it, but some sources were unavoidably excluded. Additionally, work is ongoing to develop linkages between registries and surveys with administrative data, including linkage among multiple data sources or multiple payors. Recently, investigators were able to link the Michigan cancer registry data with both Medicare and Medicaid.²⁷ Data linkage efforts with Medicare, Medicaid, and additional data sources, including private payors, are ongoing in other states.

Ultimately, investigators must weigh the strengths and weaknesses of different data sources for their specific research questions. Considerations include the representativeness of the data source to the population of interest, the appropriate level of aggregation, the need for information from single or multiple payors (eg, Medicare, Medicaid, private), types of services or resources measured, period of observation (longitudinal versus cross-sectional), and need for accurate identification of patients with specific conditions (eg, cancer). As illustrated in 2 articles in this supplement, accurate identification of patients for either incidence or prevalence cost estimates is critical in cancer^7,8; the method of patient identification may be less critical for other diseases. In the case of simulation models, which may integrate cost estimates from multiple sources, similarity of patient populations and types of resources measured across sources may be a key consideration. Other issues, such as periodicity and most recent year of cost data may also be important for studies of trends in health care costs or in studies tracking the dissemination of new therapies. Finally, feasibility, ease, and cost of accessing the data may also be important considerations for selecting the most appropriate data source for estimating health care costs for the specific research question.