Managed Care, Networks and Trends in Hospital Care for Mental Health and Substance Abuse Treatment in Massachusetts: 1994-1999

Background: Rates of inpatient care for mental health and substance abuse treatment have been reported to fall after the introduction of managed care, but the actual decline may be overstated. Almost all managed care impact studies are based on pre-post comparisons, which have two drawbacks: secular downward trends may be attributed to a managed care effect and self-selection may exaggerate the impact of managed care. Therefore it is useful to examine long-term population-based trends in use associated with the growth of managed care. Aims of Study: This paper examines trends in inpatient care for mental health and substance abuse treatment in Massachusetts between 1994 and 1999 by service provider and payer. We analyze how managed care impacts the trends in mental health and substance abuse care