Assessing the impact of peer-led harm reduction on people experiencing homelessness and problem substance use: The SHARPS study

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

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN11094645

Enrollment

550

Registered

2024-04-05

Start date

2024-07-30

Completion date

Unknown

Last updated

2026-03-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Improvement of mental health and quality of life in people experiencing homelessness and problem substance use. Mental and Behavioural Disorders

Interventions

The intervention that will be assessed is a relational, peer-delivered intervention for those experiencing homelessness and problem substance use. It was developed during the SHARPS feasibility study.

housing

benefits

help to access benefits

and setting up and advocacy within multi-agency appointments. Psychosocial and emotional support may include: listening

being consistent and reliable

helping to secure volunteering and employment opportunities

and helping to (re)connect with family and friends. A fund will also be available to the PNs to pay for travel, food, hot

Eligibility

Sex/Gender

All

Age

18 Years to 100 Years

Inclusion criteria

Inclusion criteria: 1. >18 years and experiencing/at risk of homelessness (ETHOS definition) 2. Self-report problem substance use (using pre-determined scoring ‘cut off’) 3. Able to provide informed consent.

Exclusion criteria

Exclusion criteria: Current exclusion criteria as of 24/10/2024: 1. Current participation in other alcohol and/or substance use intervention trials 2. Inability to give clear informed consent due to serious mental illness or cognitive impairment or posing a safety risk to staff members/PN or individuals who are actively disclosing suicidal intent 3. Non-English speaking (due to the intervention involving Peer Navigator relationship and they will not necessarily have languages other than English). Previous exclusion criteria: 1. Current participation in other alcohol and/or substance use intervention trials 2. Inability to give clear informed consent due to serious mental illness or cognitive impairment or posing a safety risk to staff members/PN 3. Non-English speaking (due to the intervention involving Peer Navigator relationship and they will not necessarily have languages other than English).

Design outcomes

Primary

Measure	Time frame
The co-primary outcomes are changes to mental health measured using the compositive Patient Health Questionnaire Anxiety and Depression Scale (PHQ-ADS) and quality of life measured using the ICEpop CAPability Measure for Adults (ICECAP-A) both from baseline to 12 months	—

Secondary

Measure	Time frame
Current secondary outcome measures as of 25/09/2025: 1. Changes to mental health measured using the Patient Health Questionnaire Anxiety and Depression (PHQ-ADS) and the ICEpop CAPability Measure for Adults (ICECAP-A) at 6 months 2. Harmful substance use measured using the Maudsley Addiction Profile (MAP) and the Leeds Dependence Questionnaire (LDQ) at 6 and 12 months 3. Risk-taking behaviours measured using the MAP at 6 and 12 months 4. Social functioning including occupation/education roles measured using the MAP at 6 and 12 months 5. Physical health measured using the MAP and European Quality of Life measured using the EuroQol health-related quality of life measure (EQ-5D-5L) at 6 and 12 months 6. Current housing status measured using self-report measure at 6 and 12 months 7. Social outcomes, therapeutic alliance with PN and support workers, and service accessibility measured using items from the Social Satisfaction Questionnaire (SSQ) at 6 and 12 months 8. Service utilisation measured using MAP, self-report hospitalisations and items from the Client Evaluation of Self and Treatment (CEST) at 6 and 12 months 9. Relational empathy measured using the Consultation and Relational Empathy measure (CARE at 6 and 12 months Previous secondary outcome measures: 1. Changes to mental health measured using the Patient Health Questionnaire Anxiety and Depression (PHQ-ADS) and the ICEpop CAPability Measure for Adults (ICECAP-A) at 6 and 15 months 2. Harmful substance use measured using the Maudsley Addiction Profile (MAP) and the Leeds Dependence Questionnaire (LDQ) at 6, 12 and 15 months 3. Risk-taking behaviours measured using the MAP at 6, 12 and 15 months 4. Social functioning including occupation/education roles measured using the MAP at 6, 12 and 15 months 5. Physical health measured using the MAP and European Quality of Life measured using the EuroQol health-related quality of life measure (EQ-5D-5L) at 6, 12 and 15 months 6. Course of homelessness measured using RAND	—

Measure

Time frame

Current secondary outcome measures as of 25/09/2025: 1. Changes to mental health measured using the Patient Health Questionnaire Anxiety and Depression (PHQ-ADS) and the ICEpop CAPability Measure for Adults (ICECAP-A) at 6 months 2. Harmful substance use measured using the Maudsley Addiction Profile (MAP) and the Leeds Dependence Questionnaire (LDQ) at 6 and 12 months 3. Risk-taking behaviours measured using the MAP at 6 and 12 months 4. Social functioning including occupation/education roles measured using the MAP at 6 and 12 months 5. Physical health measured using the MAP and European Quality of Life measured using the EuroQol health-related quality of life measure (EQ-5D-5L) at 6 and 12 months 6. Current housing status measured using self-report measure at 6 and 12 months 7. Social outcomes, therapeutic alliance with PN and support workers, and service accessibility measured using items from the Social Satisfaction Questionnaire (SSQ) at 6 and 12 months 8. Service utilisation measured using MAP, self-report hospitalisations and items from the Client Evaluation of Self and Treatment (CEST) at 6 and 12 months 9. Relational empathy measured using the Consultation and Relational Empathy measure (CARE at 6 and 12 months Previous secondary outcome measures: 1. Changes to mental health measured using the Patient Health Questionnaire Anxiety and Depression (PHQ-ADS) and the ICEpop CAPability Measure for Adults (ICECAP-A) at 6 and 15 months 2. Harmful substance use measured using the Maudsley Addiction Profile (MAP) and the Leeds Dependence Questionnaire (LDQ) at 6, 12 and 15 months 3. Risk-taking behaviours measured using the MAP at 6, 12 and 15 months 4. Social functioning including occupation/education roles measured using the MAP at 6, 12 and 15 months 5. Physical health measured using the MAP and European Quality of Life measured using the EuroQol health-related quality of life measure (EQ-5D-5L) at 6, 12 and 15 months 6. Course of homelessness measured using RAND

—

Countries

England, Scotland, United Kingdom

Contacts

Public ContactHannah Carver

hannah.carver@stir.ac.ukNone provided

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Mar 14, 2026