This review describes the types of interventions used to reduce risk of drug harms, including death, among adults during transition of care and between services.

Findings
• Very limited evidence base, with most studies from USA. Outcomes excluded perceptions of service providers and no studies looked at patient survival or other individual outcome measures.
• Evidence of effectiveness of in-person and digital methods for establishing trust and contact.
• Stable housing and employment, practical assistance and funding to address basic needs, can decrease gaps in care and address support needs.
• Including a variety of these models and having more than one model in operation appears to improve service delivery.
• The unmet needs of the population group are substantial and, in some studies, acted as a barrier to engagement of the intervention being offered.

Recommendations
• Design in-staff autonomy and devolved budget responsibilities to allow staff to understand and address individual needs of people at risk of harm.
• Given the scale of unmet need, assess the outcome of ‘referral’ to other services.
• Evaluation of interventions for acceptability and effectiveness