Health status and health care use by type of private health coverage.

There is considerable speculation on the causes of the frequently observed lower rates of hospital use by group practice--or HMO--members than by persons covered by other health care arrangements. It is often asserted that HMO enrollees are a self-selected healthier population, or that their use of hospitals is not fully recorded. A major study in California of the actual health and use of hospitals by a representative sample of persons under age 65 showed these assertions to be unfounded.