Abstract
BACKGROUND AND AIMS: Substance-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. DESIGN: Retrospective cohort study. Electronic health records data were linked with five registries covering, among other aspects, clinical history and healthcare consumption. SETTING: The Stockholm SUD-ED, Sweden. PARTICIPANTS: n = 9771 SUD-ED patients during a sixteen-month period (2018-2019). MEASUREMENTS: For 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. FINDINGS: Of 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). CONCLUSIONS: The 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.