Predictors of alcohol and other drug treatment completion among young people accessing residential and community-based treatment: A retrospective analysis of routinely collected service data

Background and aims: Young people accessing alcohol and other drug (AOD) treatment experience high rates of treatment disengagement, contributing to poorer outcomes. To improve outcomes, it is important to identify factors associated with treatment retention. This study measured the relationships between client characteristics, treatment characteristics, clinical severity measures and completion of treatment among young people. Design, setting and participants: This study was a retrospective analysis of routinely collected data set in residential- and community-based AOD services in New South Wales, Australia. Routinely collected data from the Network of Alcohol and Other Drug Agencies' (NADA) database were used. Included individuals were aged 10-24 years and accessed treatment between 2012 and 2023 (n = 17 474). Measurements: Variables included client-related characteristics, service characteristics and baseline measures of clinical severity [Kessler-10 (K10), EUROHIS-QoL, severity of dependence scale (SDS)]. Multivariable binary logistic regression models assessed the relationships between these characteristics and treatment completion. Findings: Rates of treatment completion were highest among adolescents in community-based treatment (57%) and lowest among young adults in residential treatment (35%). Polysubstance use was negatively associated with treatment completion among adolescents [adjusted odds ratio (adjOR) = 0.71, P < 0.001] and adults (adjOR = 0.70, P < 0.001) in community-based treatment, and adolescents in residential treatment (adjOR = 0.62, P = 0.006), as was housing insecurity (adolescents in community treatment, adjOR = 0.61, P = 0.001; adults in community treatment, adjOR = 0.77, P = 0.002; adolescents in residential treatment, adjOR = 0.42, P = 0.005). Attending youth-specific services was associated with higher treatment completion rates among adults in community-based (adjOR = 1.81, P < 0.001) and residential treatment (adjOR = 1.72, P < 0.001). Varying correlates of treatment completion were identified throughout treatment groups, reflecting the differences in population and/or needs across contexts. Conclusions: In New South Wales, Australia, fewer than half of young people accessing alcohol and other drug treatment between 2012 and 2023 completed treatment, and completion rates were lower among those facing barriers such as polysubstance use and housing insecurity.