Association between substance use disorder status and pain-related function following 12 months of treatment in primary care patients with musculoskeletal pain

The goal of this study was to examine relationships between substance use disorder (SUD) history and 12-month outcomes among primary care patients with chronic noncancer pain (CNCP). Patients were enrolled in a randomized trial of collaborative care intervention (CCI) versus treatment as usual (TAU) to improve pain-related physical and emotional function. At baseline, 72 of 362 patients (20.0%) had a history of SUD. Compared to CNCP patients without SUD, those with comorbid SUD had poorer pain-related function and were more likely to meet criteria for current major depression and posttraumatic stress disorder (all P values <.05). Logistic regression analyses were conducted to examine whether SUD status was associated with clinically significant change over 12 months in pain-related function (30% reduction in Roland Morris Disability Questionnaire Score). The overall model was not significant in the CCI group. However, within the TAU group, participants with a SUD history were significantly less likely to show improvements in pain-related function (OR = .30, 95% CI = .11-.82). CNCP patients with comorbid SUD reported greater functional impairment at baseline. Patients with SUD who received usual care were 70% less likely to have clinically significant improvements in pain-related function 12 months postbaseline, and SUD status did not impede improvement for the CCI group. Perspective: Chronic noncancer pain patients with a history of a substance use disorder (SUD) report poorer pain-related functioning and are less likely to experience clinically significant improvements from usual pain treatment. Providers should assess for SUD status and provide more intensive interventions for these patients.