Abstract
AIM: Emerging adulthood is a critical period for health interventions. The gender gap in substance use disorder (SUD) prevalence between men and women has been consistently narrowing, particularly amongst emerging adults (EAs), yet women remain underrepresented in SUD research. This study aims to investigate pretreatment and treatment dropout rates and predictors in patients at a Women-Specific Outpatient Service in Brazil, across different age strata: emerging adults (EAs, 18-25), middle aged adults (MAAs, 26-59), and older adults (OAs, 60+). METHODS: An observational cohort study across 27 years. Pretreatment dropout was evaluated with multivariate logistic regression. Survival curves with dropout as event were estimated for each age stratum and log rank tests were performed. Survival probabilities and Cox proportional hazards models were used to gauge dropout risk and determine dropout risk factors. RESULTS: The 756 women were included, comprising 125 EAs, 585 MAAs, and 46 OAs. MAAs showed lower odds of pretreatment dropout than EAs (OR = 0.56, p = 0.025). EAs exhibited lowest treatment retention, with only 13% remaining in treatment at 104 weeks (p < 0.0001). Cox regression indicated that higher education was protective, with tertiary education reducing dropout risk (HR = 0.65, p = 0.038), whilst cocaine/crack use increased it (HR = 1.57, p = 0.017). Patients enrolled in more recent years had a higher risk of dropout whithin the first six months of treatment. CONCLUSIONS: Emerging adulthood is a critical period for health interventions. The gender gap is narrowing amongst EAs, and women are still underrepresented in studies. We found very high pretreatment and treatment dropout rates amongst Emerging Adults in our sample. These findings underscore the necessity for early-stage risk stratification and intervention protocols for this subpopulation.