A multidisciplinary weight management intervention for adults with severe mental illness in forensic psychiatric inpatient services (Motiv8): a single blind cluster-randomised wait-list controlled feasibility trial.

Background: People with severe mental illness experience physical health inequalities and a 15-20-year premature mortality rate. Forensic inpatients are particularly affected by restrictions on movement, long admissions, and obesogenic/sedative psychotropic medication. We aimed to establish the feasibility and acceptability of Motiv8, a multidisciplinary weight management intervention co-produced with service users for forensic inpatients. Methods: A randomised waitlist-controlled trial of Motiv8(+Treatment-As-Usual) vs.TAU was conducted in medium-secure forensic services in Greater Manchester. Motiv8 is a 9-week programme of exercise sessions, diet/cooking classes, psychology, physical health/sleep education, and peer support. Physical and mental health assessments were conducted at baseline/10-weeks/3-months. A nested qualitative study captured participant experiences. A staff sub-study explored ward environment. Results: We aimed to recruit 32 participants (four cohorts). The trial met recruitment targets (n=29, 90.9%; 4 cohorts, 100%), participants were randomised to Motiv8+TAU (n=12) or waitlist (control) (n=17). Acceptable retention rates were observed (93.1%, 10-weeks; 72.4%, 3-months), and participants engaged well with the intervention. The blind was maintained, and no safety concerns raised. Assessment completion was high suggesting acceptability (>90% for people retained and engaged in the study). Participants reported high levels of satisfaction. Conclusions: The trial was not powered to detect group differences. However, data suggests it is feasible to conduct a rigorous, methodologically robust study of Motiv8 vs.TAU for adults on forensic inpatient units. Motiv8 was acceptable with potential promise providing evidence to proceed to a definitive trial for males. A larger trial is needed to explore potential effectiveness and reduce physical health inequalities for people with SMI. Clinical trial registration: https://doi.org/10.1186/ISRCTN13539285, identifier ISRCTN13539285.