Peer models in hepatitis C healthcare service delivery: underlying mechanisms and implementation

Background. The impact of peer-led work among marginalised populations with very limited access to healthcare is a key recommendation within the WHO Global Health Sector Strategies on blood borne viruses (including hepatitis C (HCV)). The benefits of peer models, i.e., people with lived experience in healthcare service delivery, are increasingly accepted. Yet, an in-depth understanding of how these models work, what influences their effectiveness, and how they are best integrated into existing healthcare settings for HCV and beyond is lacking.
Objective. (1) To examine HCV peer models and outcomes in the literature, and (2) to systematically describe and evaluate a national peer service in community HCV healthcare services in the UK.
Methods. We conducted a scoping review examining the peer-reviewed HCV literature on peer models (2012-2022), in OECD countries, and published in English. We included all studies that described, designed and evaluated HCV peer models and interventions. We then conducted a qualitative process evaluation (PEERs study) of the Hepatitis C Trust peer model in the UK. We interviewed 45 peer workers, service users and healthcare professionals in diverse community healthcare settings across three research sites. All data were thematically analysed through a complex intervention framework lens.
Results. Based on 29 included peer-reviewed studies, we identified the perceived benefits and impacts of lived experience in HCV services. However, key findings on ‘how’ peer models work in practice were often poorly or not at all documented, thus affecting the scalability and transferability of peer models. In response, our qualitative study presents key elements underpinning the mechanisms, processes and impacts of HCV peer models. Facilitators supporting HCV peer models included the importance of lived experience for service users and peer workers, and the incremental benefit of a peer organisation co-ordinating the peer model. Underlying mechanisms include social influence, professional roles and transitional identities, and beliefs about capabilities and consequences.
Conclusion. Peer models and how they work as a complex intervention are poorly described in the HCV literature. Our qualitative study demonstrates that peer-enhanced healthcare service delivery is valuable when embedded within healthcare systems. In the absence of practical guidance in the literature, the lessons learned from our study provide recommendations and rationales for other services intending to implement peer models in HCV and beyond to optimise engagement and healthcare provision for marginalised populations.