A community-based, peer-led counseling service: a hybrid type 3 effectiveness-implementation study protocol

Background Mental health care is undergoing a fundamental shift, with a growing international call for recovery-oriented services, emphasizing hope and empowerment. Support through trained peers plays a substantial role in this shift. Recent meta-analyses show that peer support has small but significant effects on recovery. However, an implementation gap also affects peer services: factors such as unclear role descriptions and poor organizational integration hinder implementation. In eastern Switzerland, a community-based, peer-led counseling service was established to address this gap. Peers offer short-term counseling to people experiencing a mental health crisis. This protocol outlines an evaluation of the service's effectiveness and implementation, using RE-AIM (Reach, Effectiveness, Adoption, Implementation, Maintenance) as a summative evaluation framework. Methods The service is evaluated using an Effectiveness-Implementation Hybrid Type 3 design. Study 1 examines changes in clients' psychological well-being and subjective recovery at two time points (t0; t1), analyzed descriptively and inferentially. Study 2 explores how clients experience counseling and the mechanisms underlying observed change, using semi-structured interviews analyzed with Framework Analysis. Study 3 identifies facilitators and barriers to implementation from multiple perspectives [peers; network partners (NWP)]. Peers and NWPs complete validated measures of acceptability, appropriateness, and feasibility; peer focus groups and NWP interviews explore implementation experience, attitudes, perceived fit, and referral barriers. Official institutional documentation and routine service data (sessions, referrals, utilization) are also analyzed. Quantitative data are analyzed descriptively and qualitative data using Framework Analysis. Findings are organized and interpreted by RE-AIM dimensions. Discussion This study addresses the implementation gap in peer support research, particularly within German-speaking countries, by providing an integrated account of the effectiveness and implementation of a community-based, peer-led counseling service under real-world conditions. Findings are expected to inform the service's ongoing development and may serve as a model for implementing and evaluating similar peer-led services elsewhere. Clinical Trial Registration https://clinicaltrials.gov/ , identifier NCT07879443