People with severe mental illness (SMI) have worse physical health than the general population. There is evidence that support from volunteers can help the mental health of people with SMI, but little evidence regarding the support they can give for physical health.

To evaluate the feasibility of an intervention where volunteer ‘Health Champions’ support people with SMI in managing their physical health.

A feasibility hybrid randomised controlled trial conducted in mental health teams with people with SMI. Volunteers delivered the Health Champions intervention. We collected data on the feasibility of delivering the intervention, and clinical and cost-effectiveness. Participants were randomised by a statistician independent of the research team, to either having a Health Champion or treatment as usual. Blinding was not done.

We recruited 48 participants: 27 to the intervention group and 21 to the control group. Data were analysed for 34 participants. No changes were found in clinical effectiveness for either group. Implementation outcomes measures showed high acceptability, feasibility and appropriateness, but with low response rates. No adverse events were identified in either group. Interviews with participants found they identified changes they had made to their physical health. The cost of implementing the intervention was £312 per participant.

The Health Champion intervention was feasible to implement, but the implementation of the study measures was problematic. Participants found the intervention acceptable, feasible and appropriate, and it led them to make changes in their physical health. A larger trial is recommended, with tailored implementation outcome measures.