Review of: "Mortality Risk for Individuals With Cocaine Use Disorders: Clients and Non-Clients of Public Treatment Centres for Drug Addiction"

This longitudinal cohort study provides valuable real-world epidemiological evidence regarding mortality risk among individuals with cocaine use disorder (CUD), particularly through its comparison of clients and non-clients of public addiction treatment services (PATS).The study's strengths include the relatively large sample size, extended follow-up period, integration of multiple healthcare databases, and use of standardized mortality ratios and multivariate Poisson regression to evaluate mortality determinants.The ndings highlighting elevated mortality risk, particularly among individuals who never accessed specialized addiction treatment, provide important public health implications.However, several methodological limitations require clari cation to strengthen the study's validity and interpretability.First, the retrospective design and reliance on routinely collected administrative data introduce potential misclassi cation bias and limit the availability of important confounding variables such as socioeconomic status, severity and duration of cocaine use, treatment adherence, and detailed comorbidity pro les.Second, the classi cation of PATS versus never-PATS exposure may be affected by selection bias, as individuals accessing treatment likely differ systematically in motivation, healthseeking behavior, and substance use patterns.Third, the relatively small number of deaths, particularly in subgroup analyses, may reduce statistical power and increase uncertainty in cause-speci c mortality comparisons.Additionally, further clari cation regarding missing data management, validation of diagnostic coding, and potential time-dependent exposure changes would improve methodological transparency.The discussion would bene t from deeper integration with international cohort ndings and clearer interpretation of gender-related mortality differences and COVID-19-related mortality trends.