Retention in treatment and therapeutic adherence: How are these associated with therapeutic success? An analysis using real‐world data

INTRODUCTION: Treatment retention and adherence are used as outcomes in numerous randomized clinical trials and observational studies conducted in the addiction field. Although usual criteria are 3/6 months of treatment retention or number of sessions attended, there is not a methodological support for conclusions using these criteria. This study analyzed the usefulness of retention and adherence to predict therapeutic success. METHODS: Retrospective observational study using real‐world data from electronic health records of 11,907 patients in treatment diagnosed with cocaine, alcohol, cannabis and opiate use disorders or harmful use. RESULTS: Moderate effect size relations were found between the different type of clinical discharge and months in retention (η (2) = 0.12) and proportion of attendance (η (2) = 0.10). No relationship was found with the number of sessions attended. Using cut‐off points (i.e., 3 or 6 months in treatment or attending 6 therapy sessions) worsens the ability to predict the type of discharge. DISCUSSIONS/CONCLUSION: Treatment retention and adherence are indicators moderately related to therapeutic success. Research using these indicators to assess the effectiveness of therapies should complement their results with other clinical indicators and quality of life measures.