How and why women’s life histories and homelessness services generate heterogeneous recovery outcomes in Barcelona: a co-created realist evaluation protocol

Introduction Homelessness is rising in Spain, particularly in Barcelona, where women are the fastest-growing subgroup, accounting for approximately 30% of service places. Yet services have historically been designed by default for men. Women’s pathways into homelessness are shaped by individual, social, and structural determinants which increase trauma exposure and make this population highly heterogeneous. While evidence highlights the need for gender- and trauma-informed services adapted to different subgroups, there remains limited systematic understanding of how women’s life experiences influence their engagement with and outcomes from homelessness services. This study aims to understand how and why women’s life experiences and determinants interact with homelessness service and intervention elements to activate or inhibit mechanisms (e.g., personal strengths) leading to different recovery outcomes (e.g., identity), thereby informing recommendations on how services can better support person-centered recovery of women. Methods This study protocol describes a realist evaluation that will combine a realist review with realist interviews, using co-creation methodologies involving homelessness service users and providers, through Community Advisory Committees, in Barcelona. An initial programme theory will be co-designed in parallel with literature screening and appraisal. Data will be analyzed to extract context–mechanism–outcome configurations explaining how women’s experiences and determinants generate different outcomes when interacting with service/intervention components. Co-refined programme theories will subsequently be tested through interviews and focus groups, with data analyzed retroductively and co-interpreted using different theoretical lenses and approaches such as the Social Determinants of Health, Trauma Theory, Trauma-Informed Care and the Power Threat Meaning Framework. Discussion The study integrates realist evaluation with co-creation methodologies, enabling the development of evidence-based, context-sensitive middle-range programme theories while prioritizing the voices of both professionals and people with lived experience in the knowledge-building process, aiming for epistemic justice. Co-created causal, feminist and trauma-informed explanatory theories linking women’s experiences, mechanisms of change and intervention outcomes in Barcelona are intended to serve as a foundation for the co-production of actionable service guidelines for homelessness, as well as policy recommendations. Findings will be disseminated to both the academic and general public and will include the participation of co-researcher stakeholders for this purpose.