Use of outpatient mental health services over time in a health maintenance organization and fee-for-service plans.

The authors compared the use of outpatient mental health services in a health maintenance organization (HMO) and fee-for-service plans over a 5-year period, using data from a randomized controlled trial. In any given year, enrollees in the HMO and a fee-for-service plan with identical benefits were equally likely to visit a mental health specialist. Over several years, the HMO enrollees were about 50% more likely ever to visit a mental health specialist; fee-for-service enrollees were more likely to receive mental health care in more than 1 study year.