Evaluation of treatment programs for persons with severe mental illness: Moderator and mediator effects

This study evaluated several statistical models for estimating treatment effects in a randomized, longitudinal experiment comparing assertive community treatment (ACT) versus brokered case management (BCM). In addition, mediator and moderator analyses were conducted. The ACT clients had improved outcomes in terms of housing and psychiatric symptoms than BCM clients. Case management housing assistance and financial assistance partially mediated housing outcomes. No reliable mediators were found for psychiatric symptoms, and no reliable moderators were found for either housing or psychiatric symptoms. The study also made several important methodological advances in the analysis of longitudinal data in randomized experiments.