Within-treatment clinical markers of dropout risk in integrated treatments for comorbid PTSD and alcohol use disorder.

ABSTRACT

BACKGROUND: Integrated interventions for comorbid posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) are effective, but many patients prematurely drop out from treatment. Little is known about within-treatment risk factors for dropout, limiting the ability during therapy to identify patients at risk for attrition. METHODS: We examined measures assessing PTSD (PTSD Checklist for DSM-5; PCL-5), alcohol use (Substance Use Inventory; SUI), and patient satisfaction (Client Satisfaction Questionnaire; CSQ-8) as potential within-treatment markers of dropout risk, administered to 110 veterans in a randomized clinical trial of integrated exposure therapy versus integrated coping skills therapy for comorbid PTSD + AUD. Hierarchical Cox proportional hazard models with dropout status as the endpoint assessed effects of PCL-5, SUI, and CSQ-8 on dropout risk, and whether effects differed by treatment modality. RESULTS: A significant interaction between treatment and changes in alcohol use was observed (HR = 2.86, p = .007), where between-session alcohol use was positively associated with dropout hazard rate for those receiving integrated exposure therapy (HR = 2.34, p = .004), but not coping skills therapy (HR = 0.73, p = .19). Specifically, an increase of one drink consumed per day in the interval since last assessment (typically 2-3 weeks) was associated with a 5-fold increase in dropout hazard rate. CONCLUSIONS: The findings provide preliminary evidence of detectable within-treatment markers of dropout during integrated treatment for PTSD + AUD. Study of within-treatment indicators proximal to dropout may help identify at-risk patients and inform timely strategies to boost retention.