RAND Health Insurance Experiment [in Metropolitan and Non-Metropolitan Areas of the United States], 1974-1982 (ICPSR 6439)

Published: Nov 4, 2005

Principal Investigator(s):
Joseph P. Newhouse, RAND Corporation


Version V1

The Health Insurance Experiment (HIE) was conducted from 1974 to 1982 in six sites across the country: Dayton, Ohio, Seattle, Washington, Fitchburg-Leominster and Franklin County, Massachusetts, and Charleston and Georgetown County, South Carolina. These sites represent four census regions (Midwest, West, Northeast, and South), as well as urban and rural areas. The HIE attempted to determine what effects alternative cost-sharing plans and a staff-model Health Maintenance Organization (HMO) had on the use of medical services and individual health outcomes. The main purpose of the experiment was to assess how the cost of health services affected individuals' use of services, their satisfaction with health care, the quality of their care, and the state of their health. To study the effects of health insurance coverage, a comprehensive method for measuring health and monitoring changes in health over time was developed. Health status was seen as having four dimensions: physical, mental, social, and physiological. Physical health focused on five categories of activities: self-care, mobility, exertion, role fulfillment, and leisure pursuits. Mental health focused on mood and anxiety disorders along with loss of control over feelings, thoughts, and behavior. Social health was assessed by the frequency of several kinds of participation, interaction, and resources, covering family and home, social life, and community involvement. Physiologic health was determined by looking at a number of physical disorders both in adults (aged 14 to 61) and children (aged 0 to 13) that would be easily traced over time and would be responsive to changes in the level and quality of medical care. For adults, acne, congestive heart failure, and sleeping pill and tranquilizer use were considered. For children, variables included allergic conditions (asthma, eczema, hay fever), anemia, middle ear disease, hearing impairment, and vision impairment. Also included were general health measures based on single questions about health-related pain and worry, and a rating of health (excellent, good, fair, poor). Health habits described aspects of smoking, consumption of alcohol, weight, height, and exercise.

Newhouse, Joseph P. RAND Health Insurance Experiment [in Metropolitan and Non-Metropolitan Areas of the United States], 1974-1982. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2005-11-04. https://doi.org/10.3886/ICPSR06439.v1

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United States Department of Health and Human Services (016B-8001)

1974 -- 1982

1974 -- 1982

The data files within some of the series names are not consecutively numbered.

Part 202, RAND Dictionary Documentation Files, is an ASCII text file and Parts 203-226 are codebooks provided as Portable Document Format (PDF) files. The PDF file format was developed by Adobe Systems Incorporated and can be accessed using PDF reader software, such as the Adobe Acrobat Reader. Information on how to obtain a copy of the Acrobat Reader is provided through the ICPSR Website on the Internet.

Due to the way missing data were coded, setup files were created to read all variables as alphanumeric only. To determine which variables need to be converted to either integer "I" or fixed-decimal "F", please refer to the appropriate documentation in Part 202, All RAND Dictionary Documentation Files.

A probability sample within each site was done by cluster sampling of census tracts and enumeration districts. Between 100 and 300 clusters were chosen in each site and every nth dwelling unit in a cluster was sampled, with n chosen to reach the required number of units for that site. Over the course of the experiment, information of some kind was obtained for 26,148 persons. There were 8,254 insured enrollees assigned to an experimental insurance treatment, and data were collected throughout their period of participation. Another 2,483 adjunct enrollees were not assigned to an insurance treatment but resided with insured enrollees or were members of a control group (669) in Dayton that was disbanded after a year. The remaining 15,411 persons who did not enroll are called "baseline-only" participants.

Eligible individuals living in households in four metropolitan areas: Seattle, WA, Dayton, OH, Charleston, SC, and Fitchburg-Leominster, MA, and in two rural counties: Franklin County, MA, and Georgetown County, SC. Eligibility criteria excluded those who were eligible for Medicare or who would become eligible during the experiment, those with family incomes over $25,000 (1973 dollars), those who were institutionalized (jail, long-term hospital), and those in the military and their dependents, along with veterans with service-connected disabilities.

household interviews, claims information, and medical screening examinations

administrative records data

experimental data

medical records

survey data



1998-02-23 Missing cases have been added to Part 91, Medical Disorders Series: Adults at Enrollment and Exit, and its corresponding SAS data definition statements (Part 92) and SAS transport file (Part 93).

2005-11-04 On 2005-03-14 new files were added to one or more datasets. These files included additional setup files as well as one or more of the following: SAS program, SAS transport, SPSS portable, and Stata system files. The metadata record was revised 2005-11-04 to reflect these additions.

1999-11-19 Hardcopy codebooks were converted to Portable Document Format (PDF) and have been added to the collection as Parts 203-226.


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This study is maintained and distributed by the National Archive of Computerized Data on Aging (NACDA), the aging program within ICPSR. NACDA is sponsored by the National Institute on Aging (NIA) at the National Institutes of Heath (NIH).