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.

Project Description

This study (award: £2,497,467.37) is funded by the NIHR Health Technology Assessment, and is being delivered in partnership with The Salvation Army, the University of Aberdeen, the University of Edinburgh, Edinburgh Napier University, the University of Victoria (Canada), Liverpool John Moores University and the Scottish Drugs Forum.

The Chief Investigator is Professor Tessa Parkes. The Joint Lead Applicant is Professor Graeme MacLennan. The Co-investigators are: Dr Hannah Carver, Dr Jacob Hawthorn, Dr Rebecca Foster, Professor Bernadette Pauly, Professor Catriona Matheson, Professor Harry Sumnall, Professor Kate Hunt, Professor Margaret Maxwell, Professor Marjon van der Pol, Professor Stewart Mercer.
The study started in April 2024 and is due to complete in April 2027.

Plain English Summary:
People who are homeless tend to have poorer mental and physical health than people who are housed. They are also more likely to have problems with substances like alcohol and other drugs. Experiences of poverty and violence are some factors relating to future homelessness. Not everyone wants to reduce or stop using substances. Harm reduction aims to lower risks from substance use, without expecting people to stop, and can improve access to essential services. People with experience of problem substance use, homelessness, and/or mental health problems often called 'peers' can provide harm reduction interventions to people who are homeless and have many benefits. These include building strong relationships and trust, improving mental health, and reducing risks from substance use. Our earlier study, called SHARPS (Supporting Harm Reduction Through Peer Support), based in six homelessness services in Scotland/England, tested if trained and paid peers, called Peer Navigators, could provide practical and emotional support to people who were homeless with problem substance use (called participants). We found that the Peer Navigators' own lived experience meant that they built trusting relationships quickly with their participants who often found it very hard to trust other staff. They successfully connected them to wider support such as GPs, housing, and social care.

In this study (SHARPS 2), we will test in a full trial whether the relationships with Peer Navigators can improve their participants' mental health and quality of life, compared to people in similar services who do not have a Peer Navigator. Peer Navigators will be based in hostels and drop-in services run by The Salvation Army. We will invite 500 people who are homeless with problem substance use from services based in 20 cities and towns in England and Scotland to participate. These services will have an equal chance to either deliver the 12-month long SHARPS intervention, or the usual support on offer. Peer Navigators will provide practical and emotional support to 25 clients to help them to make changes in their lives and improve their mental health and quality of life. We will compare people's mental health/quality of life in the services that had the Peer Navigators with those that had the usual support. We will measure mental and physical health, quality of life, use of alcohol and other drugs, access to social support, and ability to participate in society, when people join the study, and again at 6, 12 and 15 months after they join the study. To understand more about how the intervention works in practice, and the wider contexts, we will run a process evaluation. We will interview a sample of participants who had a Peer Navigator at the end of the intervention and three months after. We will also interview the Peer Navigators, a sample of wider staff members, and people who fund/commission services. We will also use a survey with staff/Peer Navigators and do observations across all services in the study. People with lived experience helped to create the SHARPS intervention and remain a key part of our study team. A UK-wide 'Experts by Experience' group will guide the project. To support take up of our findings and impact, especially amongst those that fund health and social care services, we will share our findings widely, through journal articles, conferences, social media, a study website, blogs, videos, and by holding events in the services that are taking part.