Effectiveness and cost-effectiveness of a peer-delivered, relational, harm reduction intervention to improve mental health, quality of life, and related outcomes, for people experiencing homelessness and substance use problems: The ‘SHARPS’ cluster randomised controlled trial.

Despite the increasing recognition of the value of peers and a growing evidence base, there are no trials that investigate the impact of peer support interventions on those experiencing homelessness and substance use. Our previous NIHR-funded feasibility study, Supporting Harm Reduction through Peer Support (SHARPS 1), responded to an NIHR HTA commissioned call: 16/153/14 Testing the feasibility and acceptability of a peer-delivered, relational intervention for people with problem substance use who are homeless to improve health outcomes, quality of life and social functioning, and reduce harms. We examined if a peer-delivered, relational intervention provided by salaried Peer Navigators who received bespoke training was both acceptable and feasible to deliver in third sector homelessness settings in Scotland and England. Our co-produced intervention was created with a team of experts, including those with lived experience, combining evidence on peer support, tri-morbidity, harm reduction, and psychologically informed environments.

The intervention and research processes were found to be acceptable to, and feasible and accessible for, participants, Peer Navigators, and service staff. Participants reported improvements to service engagement and feeling more equipped to access services independently. While SHARPS 1, as a feasibility study, was not powered to produce definitive data on effectiveness, participants did report experiencing a range of positive outcomes, including reductions in drug use and risky injecting practices.

There is now a need for a randomised controlled trial focused on people who experience homelessness and use substances harmfully to assess effectiveness and cost-effectiveness of peer support interventions. This current study, also funded by NIHR Health Technology Assessment, which we are calling SHARPS, will be delivered in partnership with The Salvation Army (TSA), the University of Aberdeen, University of Edinburgh, Edinburgh Napier University, the University of Victoria, Canada, Liverpool John Moores University and Scottish Drugs Forum. TSA/University of Stirling have had a community-university partnership since February 2017 which provides a sustainable platform for this proposed trial. For more information please contact the study Research Fellow Dr Jen Boyd Jennifer.boyd1@stir.ac.uk