Background: Retention in treatment for individuals with comorbid posttraumatic stress disorder (PTSD) and substance use disorders (SUD) is an area of concern in treatment outcome studies. The current study explores key variables related to retention in a group of women with comorbid PTSD and SUD enrolled in community SUD treatment randomized to eight weekly sessions of a trauma adapted mindfulness-based relapse prevention (TA-MBRP) or an integrated coping skills (ICS) group intervention. Methods: Two unadjusted and adjusted logistic discrete failure time (DFT) models were fit to examine associations between participants and the time (in weeks) to treatment completion status. Key covariates of interest, including time-varying PTSD Symptom Scale-Self Report (PSS) total score, time-varying Five Factors Mindfulness Questionnaire (FFMQ) total score, group assignment, baseline endorsements of substance use and demographics such as age, race and employment status were fit into the model. Results: In the adjusted PSS model, increased levels of PTSD symptom severity (PSS) scores at week 5 and 7 (PSS OR: 1:06: OR 1.13, respectively) were associated with higher odds of non-completion. In the FFMQ model, increased levels of FFMQ scores at week 6 (OR: 0:92) were associated with lower odds of non-completion. In both models, assignment to the ICS control group and unemployment were associated with lower odds of completion and baseline use of cocaine and sedatives were associated with higher odds of completion. Conclusion: Monitoring PTSD symptom severity and measures of mindfulness can inform providers on strategies to enhance retention early in treatment for individuals with comorbid PTSD/SUD.ClinicalTrials.gov # NCT02755103.
Keywords: Treatment completion; alcohol/substance use disorder; posttraumatic stress disorder.