Effects of managed mental health care on service use in urban and rural Maine.

This study takes advantage of a "natural experiment" resulting from the reassignment of all Maine state employees to a managed behavioral health plan in December 1992. By comparing mental health claims before and after that date, the effects of a behavioral health carve-out on mental health utilization by rural and urban beneficiaries were investigated. Following the implementation of the carve-out, the penetration rate, defined as the proportion of beneficiaries who sought help for an affective disorder, increased significantly in both rural and urban areas (P < 0.001). However, the rural penetration rate remained significantly lower than the urban rate (before implementation, 25.8 vs. 52.2 users per 1,000 enrollees, P < 0.001; after implementation, 57.8 vs. 85.8 users per 1,000 enrollees, P < 0.001). Similarly, rural utilization rates, defined as the average number of outpatient mental health visits per user, were significantly lower than urban rates both before and after implementation of the carve-out (before, 9.2 us. 12.9 visits per user, P < 0.001; after, 9.8 vs. 13.3 visits per user, P < 0.001). Before-after differences were not significant. In addition, the proportion of mental health care provided in the primary care setting increased after implementation of the carve-out (from 9.5 percent of all visits before to 12.6 percent of all visits after, P < 0.001). The increase in penetration rates can be attributed, in part, to a member education initiative undertaken during the transition from fee-for-service to managed care. This type of carve-out arrangement does not threaten to reduce access to mental health services, provided the managed behavioral health organization (MBHO) managing the carve-out is willing to accept primary care practitioners as part of its provider network.