Assertive community treatment (ACT) is an extensively studied and widely imitated community support treatment model for severely mentally ill individuals. Several previous reviews have documented its favourable effects on clients and their families. This is the first review to focus on economic outcomes. Nineteen randomized studies and 15 nonrandomized studies describing ACT programs were identified based on 2 criteria: 1) provision of services primarily in the community and 2) shared caseloads. Percentage reduction in hospital days was calculated for the 34 study sites where reported data allowed it. Multiple-regression methods were used to relate reduction in hospital days to program fidelity and other contextual factors. The impacts of ACT on emergency-room use, use of outpatient services, housing, costs, and other economic outcomes were also examined. Higher-fidelity programs appear to reduce hospital days by about 23 percentage points more than lower-fidelity programs (95% CI = -41.2, -5.2). The estimated regression coefficients imply that a high-fidelity program reduces hospitalizations by about 58% over 1 year if the alternative involves some type of case management and by 78% if it does not. ACT appears to increase the proportion of clients who live in independent housing situations, but the effect on use of supervised housing, and therefore on housing costs, is ambiguous. The effects on use of most other resources are inconsistent across studies. Overall, ACT appears to result in somewhat lower costs, whatever the perspective of analysis adopted. The most reliable cost offset to ACT treatment costs appears to be reduced hospital use. Using Quebec costs, an ACT program must enroll people with prior hospital use of about 50 days yearly, on average, to break even. As care systems evolve to reduce their reliance on hospitalization as a care modality with or without ACT, this threshold will become increasingly difficult to achieve. The primary justification for implementing ACT services will then become their clinical benefits.
