Treatment and recovery from opioid use disorder: The role of pain severity in individuals with moderate to severe pain

Abstract

Background: Pain is a frequent comorbidity among individuals with opioid use disorder (OUD), yet its impact on treatment outcomes is unclear. This study examined associations between pain severity and OUD treatment outcomes, including abstinence, craving, retention, and psychological functioning, in participants receiving longacting buprenorphine (BUP-XR). Methods: This secondary data analysis investigates participants from a BUP-XR phase 3 program: randomized clinical trial (NCT02357901; N = 192), open-label study (NCT02510014; N = 410); and a longitudinal observational follow-up (NCT03604861; N = 350). Pain was measured using the Brief Pain Inventory (BPI) at each treatment visit. Additional measures included demographics, opioid use, participant retention, opioid withdrawal, craving, depression, and quality of life. Analyses were performed on the full sample and the subgroup of individuals with moderate-to-severe pain (BPI≥4). Results: Participants averaged 40 years old, predominantly male (67%) and White (66%). Pain decreased after starting BUP-XR, and the reduction in pain continued throughout treatment (p-values<.001). For individuals with moderate-to-severe pain, greater concurrent pain severity was associated with lower abstinence rates (odds ratios: [0.801,0.852]; p-values<.001) in two datasets. Pain was not associated with participant retention. Lastly, greater pain severity was associated with worse physical quality of life (p-values<.001) and opioid withdrawal (pvalues<. 001), and greater depression (p-values<.001) and opioid craving (p-values<.001). Collectively, these findings are well replicated across three studies. Conclusions: Pain severity is a clinically relevant predictor of opioid use and psychosocial outcomes, but not treatment retention, in patients receiving BUP-XR. Routine pain severity monitoring may provide valuable insight into patient trajectories and support more tailored treatment approaches in OUD.