Accounting for case manager effects in the evaluation of mental health services.

Three methods of accounting for case manager effects in tests of the efficacy of mental health services are explored. These methods include (a) treating the case manager as a fixed factor, (b) treating the case manager as a random factor, and (c) examining service effects within the case manager. They are demonstrated with data from a nationally known case management program serving individuals with serious and persistent mental illness. Specifically, 3 conceptually distinct types of services provided or brokered by case managers are identified: habilitation-rehabilitation, community support, and traditional psychiatric services. The effectiveness of each in improving clients' adjustment is then examined with multiple regression adjustment strategies and each of the 3 methods to account for case manager effects. The results provide strong support for effects attributable to case managers and some support for the efficacy of habilitation-rehabilitation and community support services beyond the effects of traditional psychiatric services.