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.