Dropout rates of in‐person psychosocial substance use disorder treatments: a systematic review and meta‐analysis

Background and Aims: Relapse rates for psychosocial substance use disorder (SUD) treatments are high, and dropout is a robust predictor of relapse. No meta-analyses have assessed dropout rates in studies of psychosocial SUD treatment. The objective of this meta-analysis, therefore, was to estimate average dropout rates of in-person psychosocial SUD treatment and evaluate potential moderators of this outcome. Design: A comprehensive meta-analysis of dropout rates of studies of in-person psychosocial SUD treatment. Studies included RCTs and cohort studies. Participants/Cases: 151 studies, 338 study arms, and 299 dropout rates including 26,243 participants. Measurements: Databases were searched for studies of SUD treatment that included an in-person-facilitated psychosocial component. Meta-analyses and meta-regressions were conducted to estimate dropout rates and identify moderators of dropout, including 22 participant characteristics, two facilitator characteristics, and 15 treatment characteristics. Pooled estimates were calculated with random-effects analyses accounting for the hierarchical structure of study arms nested within studies. Findings: The average dropout rate across all studies and study arms was 30.42%(95% CI[27.22,33.83], 95% PI[6.25,74.15]) with substantial heterogeneity (I2=93.7%, p