Assertive community treatment for adults with complex mental illness and emergency department use: a systematic review.

INTRODUCTION: Emergency Department (ED) wait times have increased globally, resulting in treatment delays and system strain. Complex mental health consumers, those with Serious and Persistent Mental Illness (SPMI), are a consistent subgroup of ED presenters. Assertive Community Treatment (ACT) has shown promise in reducing inpatient demand but has been criticized as cost-intensive with limited rehabilitation outcomes. This systematic review evaluated ACT's effectiveness in reducing ED usage and improving psychosocial outcomes. METHODS: Nine databases were searched (31/12/2013-25/10/2023), yielding studies with moderate Risk of Bias scores. Studies spanned urban and rural areas across diverse geographic regions (Asia Pacific, Europe, North America). RESULTS: ACT was associated with reductions in ED presentations and costs in seven studies. Improvements in psychosocial functioning were documented in five studies, although symptom reduction was limited. These findings were primarily based on clinician-reported Routine Outcome Measures (ROMs), with minimal inclusion of patient-reported outcomes, limiting interpretive reliability. DISCUSSION: The evidence suggests that ACT programs reduce the incidence of, and costs associated with ED use and improve patient wellbeing (particularly social functioning) in participants with SPMI. The absence of comparisons between ED savings and ACT implementation costs restricts conclusions about sustainability. These results are limited in generalizability due to a moderate risk of bias related to confounding variables. Future research should explore client perspectives and cost-benefit analyses. In the interim, ACT may be an appropriate intervention for clients with SMPI and high ED usage who are unable to be managed via case management teams. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/view/CRD42023474465, identifier CRD42023474465.