Long-Term Mental Health and Functional Outcomes Among Adults Referred for Gender-Affirming Care: Protocol for a Longitudinal Mixed Methods Cohort Study (GLOW)

Background Gender dysphoria is associated with impaired functioning, reduced quality of life, psychiatric symptoms, and increased health care needs. Although gender-affirming care is increasingly provided, studies of long-term outcomes remain insufficient, particularly studies using prospective designs integrating self-reported, clinical, registry-based, and qualitative data. Objective The Gender Longitudinal Outcomes and Well-being (GLOW) study aims to investigate long-term psychosocial, functional, and medical outcomes among adults referred for gender dysphoria assessment within the Swedish National Highly Specialized Care system. The primary aim is to estimate change in functional disability between the time of assessment completion and 24 months afterward. Secondary aims are to assess quality of life, gender congruence, psychiatric symptoms, substance use, self-concept clarity, personality functioning, health care use, work-related outcomes, mortality, and lived experiences of gender-affirming health care. Methods GLOW is a prospective longitudinal observational mixed methods cohort study embedded in the Swedish National Highly Specialized Care system for adult gender dysphoria. The target sample is approximately 500 adults. Patient-reported outcomes are collected at baseline, assessment completion, and 24 and 60 months after completion. The primary outcome is World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0). Medical record and national registry data cover clinical exposures, health care use, medication, socioeconomic and work-related outcomes, and mortality. Semistructured interviews will be conducted with a purposive subsample of approximately 25 to 40 participants at either assessment completion or 24 months. Results The study was funded in 2025. Recruitment began in December 2025 at the Malmö clinic and in January 2026 at the Linköping clinic. As of September 2026, 174 participants had enrolled. Follow-up data collection is scheduled to continue through December 2030. Data analysis is expected to begin in spring 2027, with the first results expected to be published in autumn 2027. Conclusions By describing longitudinal trajectories and associations across self-report, clinical, registry, and qualitative data, the GLOW study is expected to strengthen the evidence base for adult gender dysphoria services. Because care pathways are not randomly assigned, comparisons between pathways will be interpreted as associations rather than causal treatment effects. Trial Registration ClinicalTrials.gov NCT07480590; https://clinicaltrials.gov/study/NCT07480590 International Registered Report Identifier (IRRID) DERR1-10.2196/101233