This codebook describes the contents of a data file from the Health Insurance Experiment (HIE), a large social experiment conducted by The RAND Corporation from 1974 to 1982 under a grant from the U.S. Department of Health and Human Services. The health maintenance organization (HMO) and Seattle fee-for-service (FFS) visits files contain data concerning the use of inpatient and outpatient health services by Seattle FFS participants and participants enrolled in Group Health Cooperative of Puget Sound, a large prepaid group practice in Seattle. These files are useful for getting an overview of the services rendered to comparable FFS and HMO populations during covered visits and hospitalizations, and the total imputed expenditures for those visits.
