The codebooks in this volume describe the contents of data files 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 Seattle fee-for-service (FFS) files for comparison with health maintenance organization (HMO) files contain data concerning the use of FFS health services by Seattle FFS participants and by participants enrolled in Group Health Cooperative (GHC) of Puget Sound, a large prepaid group practice in Seattle. In the latter group, the data primarily represent GHC participants' uses of FFS health services that were not covered by GHC. These files were created specifically to enable comparisons between the use of health services in an FFS setting and that in an HMO setting.
