["Addiction, Volume 121, Issue 5, Page 1237-1248, May 2026. ", "\nAbstract\n\nBackground and aims\nSubstance‐related emergency department (ED) visits represent a critical opportunity to link individuals with sustained treatment for substance use disorders (SUD), yet few transition to post‐acute treatment. Among emerging initiatives to integrate specialized SUD care into ED services, the Stockholm SUD‐ED is an example of a fully integrated model that remains unmapped. This study aimed to systematically map care pathways and identify predictors of post‐acute SUD treatment engagement among SUD‐ED patients in Stockholm.\n\n\nDesign\nRetrospective cohort study. Electronic health records data were linked with five registries covering, among other aspects, clinical history and healthcare consumption.\n\n\nSetting\nThe Stockholm SUD‐ED, Sweden.\n\n\nParticipants\nn = 9771 SUD‐ED patients during a sixteen‐month period (2018–2019).\n\n\nMeasurements\nFor care flow mapping, post‐acute SUD treatment engagement was defined as ≥2 outpatient visits during a six‐month follow‐up. Four engagement levels (none, low, moderate, high) were derived using a quantile regression approach and regressed on 19 candidate predictors in multinomial logistic regression models.\n\n\nFindings\nOf all SUD‐ED patients, one‐third (33.2%; n = 3248) primarily engaged in post‐acute outpatient SUD treatment, 16.9% (n = 1651) primarily engaged in non‐SUD psychiatric services and 49.9% (n = 4872) did not engage in either. Police‐initiated admissions had lower odds of moderate or high post‐acute treatment engagement than ambulance‐initiated admissions [high engagement: adjusted odds ratio (aOR) = 0.71, 95% confidence interval (CI) = 0.53–0.95]. Prior needle and syringe program visits increased the odds of post‐acute treatment engagement (aOR = 2.09, 95% CI = 1.59–2.75). Lack of prior SUD outpatient treatment was consistently associated with lower odds of post‐acute engagement across all levels (e.g. moderate engagement: aOR = 0.3, 95% CI = 0.25–0.35).\n\n\nConclusions\nThe Stockholm model for fully integrating specialized substance use disorder care into emergency departments appears to generate high post‐acute treatment engagement and highlights the need for (1) targeted interventions for police‐initiated admissions and (2) broad aftercare options to better attract treatment‐naïve patients.\n\n"]