Effectiveness of a substance use treatment program for veterans with chronic pain and opioid use disorder.

Objective: Veterans suffer disproportionately from the combined adverse health impacts of chronic pain and hazardous opioid use. This evaluation involved a substance use treatment program that included medication for opioid use disorder (SATP-MOUD) in a large metro-area Veterans Health Administration (VHA). This form of treatment has become increasingly important during the opioid crisis and is among several important Department of Veteran's Affairs (VA) initiatives to improve treatment for opioid use disorder (OUD), for which chronic pain is often a comorbid condition.

Methods: We compared clinical measures related to substance use and mental health between groups who were considered either engaged or not engaged in completing treatment. The study used propensity score matching methods and Cox proportional hazards models to compare the mortality risk for treated and untreated veterans who had chronic pain with concurrent opioid use.

Results: We identified 1559 SATP-MOUD patients with 1 year of pre- and post-treatment follow-time. From those with chronic pain and concurrent opioid use, we matched 478 SATP-MOUD patients to 647 untreated patients. Engaged patients (at least 4 visits in the first 8 weeks of treatment) had significant improvements in Brief Addiction Monitor (BAM) scores and in PHQ-9 depression screening scores compared to those who started treatment but did not meet the engagement threshold. In Cox proportional hazards analysis, participation in SATP-MOUD was associated with a 38% lower mortality risk among veterans with chronic pain and opioid use when compared to the untreated group: (HR: 0.62, 95% CI: 0.47, 0.82).

Conclusions: SATP-MOUD, as delivered in actual practice, was associated with significant improvements in depression and addiction severity scores, and was associated with reduced mortality risk for veterans with chronic pain and OUD.