COMPEERS: A Cluster Randomised Feasibility Study of Contingency Management and PEER Support to Promote Attendance, Increase Treatment Engagement and Improve Outcomes for People with Dual Diagnoses of Psychosis and Drug/Alcohol Problems. Study Protocol with Commentary.

Dual diagnoses of psychosis and drug or alcohol problems (DDp) are prevalent, high-cost presentations, reliably associated with poorer outcomes and greater difficulty engaging with mental health services compared to either condition alone or other mental health problems. Engagement difficulties restrict access to recommended care that could improve outcomes, and thus are a priority treatment target. Contingency management (financial incentives for positive health behaviours, CM), peer support, and text messaging each improve engagement for psychosis or drug/alcohol problems. Despite the high potential to improve engagement and thus clinical and economic outcomes in DDp, their combined impact remains unevaluated in this poorly treated and hard-to-reach population. We plan a confirmatory trial to test, for the first time, the impact on engagement in DDp of adding CM to usual care alongside text message reminders and peer support. Methodological innovation is required to ensure adequate rates of recruitment, retention, and outcome completion; as well as standardised delivery of interventions, particularly CM, which will be delivered by peer support workers, and will target attendance, to improve engagement in recommended treatments. We comment here on the protocol for CoMPEERS (ISRCTN90137206), a study to test the feasibility of progressing this novel design to a full trial.