Strengthening evidence-based practices in assessment and treatment planning for substance use disorder: an evaluation of a Swedish training program for social services

Background and aim Social workers regularly encounter clients affected by substance use disorders (SUD), yet training in evidence-based assessment and interventions remains limited. In Sweden, municipal social workers have statutory responsibility for SUD assessment, intervention planning and client follow-up which underscores the need for targeted professional education. This study aimed to: (i) describe social workers’ baseline self-assessed competence in evidence-based practices for SUD and its associations with demographic and professional characteristics, and; (ii) examine knowledge gains associated with completion of an evidence-based educational intervention. Methods A non-randomized pre–post design included 173 municipal social workers recruited from 64 municipalities across five cohorts (2021–2023). Baseline self-assessed competence was analyzed using ordinal logistic regression, and knowledge gains were assessed using module-specific pre–post items with paired t -tests with Cohen’s d . Results Baseline competence was rated as low to moderate, with professional experience predicting higher perceived competence. Substantial baseline knowledge gaps were observed, particularly in evidence-based psychosocial interventions and use of digital technology in assessment and planning of treatment. Knowledge increased significantly across all modules after training completion ( d = 0.26–1.41). The largest knowledge gains were for modules on use of technology in the assessment and treatment-planning, biopsychosocial interventions, research-informed use of the assessment tool Addiction Severity Index (ASI), and the professional role in assessment and care planning. Score variability decreased across several modules. Conclusion Completion of an immersive, online, evidence-based training was associated with meaningful improvements in social workers’ knowledge related to substance use assessment, intervention planning, and use of technology. Although causal inference is limited by the non-randomized single-group pre–post design, the findings support the potential of scalable educational interventions to address competence gaps in substance use services even in organizations with high caseloads, workforce turnover, and limited training opportunities.