Mental health services: utilization by low income enrollees in a prepaid group practice plan and in an independent practice plan.

Mental health services were included in a comprehensive package of benefits available to low income enrollees in a prepaid group practice plan (PGP) and in an independent practice plan (IPP) under the Seattle Prepaid Health Care Project. There were no out-of-pocket costs for enrollees. Utilization of services was studied for four years under conditions that might simulate universal entitlement. The analyses indicated that females used substantially more mental health services than males and that enrollees aged 20-44 used more services than those in other age groups. The prepaid group practice generally experienced higher utilization than the prepaid independent plan. Significant racial differences were evident with whites using more services than blacks and black males using strikingly few services. The prepaid independent plan was oriented toward physician providers and emphasized individual psychotherapy while the prepaid group practice employed a diversity of practitioners and therapeutic modalities. The data indicated that the per cent of enrollees using any mental health services was twice as great in the PGP as in the IPP. However, once access to the provider system was achieved, the number of services utilized was greater in the PGP. Inpatient services were also examined. A significantly higher proportion of IPP enrollees were admitted for inpatient care as compared to PGP enrollees. Finally, the cost of mental health services was less than ten per cent of total health service costs in both plans.