The evolution of psychiatric services in a health maintenance organization.

The authors describe a prepaid mental health service program in which outpatients referrals were 34.7 per 1,000 members per month, the hospital admission rate was .80 admissions per 1,000 members per year, and the average length of hospital stay was 5.03 days. They offer several explanations for their finding that the costs for mental health services in this program appear lower than those in fee-for-service programs.