PTSD improvement and substance use disorder treatment utilization in veterans: Evidence from medical record data

Background: Clinical trials reveal posttraumatic stress disorder (PTSD) improvement leads to decreased substance use among patients with comorbid substance use disorder (SUD). Using administrative medical record data, we determined whether clinically meaningful PTSD Checklist (PCL) (>= 20 points) score decreases were positively associated with SUD treatment utilization. Methods: We used a retrospective cohort of Veterans Health Affairs (VHA) medical record data (2008-2015). PTSD Checklist (PCL) scores were used to categorize patients into those with a clinically meaningful PTSD improvement (>= 20 point decrease) or not (<20 point decrease or increase). PTSD and SUD were measured by ICD-9 codes. Propensity score weighting controlled for confounding in logistic and negative binomial models that estimated the association between clinically meaningful PTSD improvement and use of SUD treatment and number of SUD clinic visits. Results: The 699 eligible patients were, on average, 40.4 (+/- 13.2) years old, 66.2% white and 33.1% were married. After controlling for confounding, there was a 56% increased odds of any SUD treatment utilization among those with a PCL decrease >= 20 vs < 20 (OR = 1.56; 95%CI = 1.04-2.33) but there was no association with number of SUD treatment visits. Conclusions: Clinically meaningful reductions in PTSD symptoms were associated with any SUD treatment utilization but not amount of utilization. Improvement in PTSD symptoms, independent of the treatment modality, may enable SUD treatment seeking.