BACKGROUND: Heterogeneity in implementing essential evidence-based early intervention for psychosis services (EIS) components persists despite existing fidelity standards/guidelines in many countries. Rapid-learning health systems (RLHS) may remedy these challenges, improving service delivery through systematic data collection, analysis, feedback and capacity-building activities. SARPEP (Système Apprenant Rapide pour les Programmes de Premiers Épisodes Psychotiques) is the first Canadian RLHS for EIS. This paper presents qualitative findings from the mixed-method study that evaluated the feasibility and acceptability of SARPEP. METHODS: We conducted six focus groups on the implementation of SARPEP with 25 participants from all SARPEP stakeholder groups
most were involved from project inception and throughout the 3-year implementation. The Reach, Effectiveness, Adoption, Implementation, Maintenance (RE-AIM) framework (Glasgow, et al., 2019) and Lessard's dimensions for learning health systems guided data collection and deductive analysis. RESULTS: Reach: focus group participants reflected SARPEP reach and included all stakeholders involved (six service users, two family members, four psychiatrists, six managers, seven team leaders) who shared their experiences. EFFECTIVENESS: participants confirmed that SARPEP improved program capacity for data collection on core indicators and promoted evidence-based practices. Adoption: participants supported the selection of specific indicators and need to improve data-gathering technologies in the RLHS, even while challenges persisted regarding the integration of digital platform use by service users into routine care. Implementation and maintenance: all participants credited the RLHS with enabling mutual learning, self-reflection of programs and shared improvement of practices. CONCLUSIONS: SARPEP contributes to promote evidence-based care and a sense of belonging within the Quebec EIS network.