Systematic Review and Meta-Analysis of the Prevalence of Chronic Pain Among Patients With Opioid Use Disorder and Receiving Opioid Substitution Therapy

To assess studies examining the prevalence of chronic pain (CP) in patients treated with Opioid Substitution Treatment (OST -buprenorphine or methadone) for Opioid Used Disorder (OUD), we conducted a systematic review and meta-analysis of the literature between the years 2000 and 2020. We searched EMBASE, PsycINFO, Cochrane, and MEDLINE databases and included studies assessing the prevalence of CP in OUD adults treated with OST. The studies were assessed for risk of bias and overall quality and the results were pooled using a random-effects model. Subgroup analy-ses and meta-regressions were used to identify possible factors associated with CP. Twenty-three studies reported data on the prevalence of CP in patients treated with OST were evaluated. The prev-alence obtained was 45.3% (CI95% [38.7; 52.1]). Overall, 78.3% of the studies had a low risk of bias. Subgroup analysis estimates did not vary according to gender, OST, and CP duration. However, it appeared that the clinical settings was associated with a lower CP prevalence when assessed in pri-mary care sites. Our study provided an estimate regarding the prevalence of CP among OST patients. These patients deserve specific attention from health professionals and health authorities. Thus, the real challenge in OST patients is the implementation of a multidisciplinary approach to manage CP.Perspective: Our meta-analysis provided an estimate of CP prevalence, reaching almost 50% of OUD patients with OST. Thus, the urgent challenge in OST patients is to pay systematic attention to chronic pain diagnosis, along with the implementation of a multidisciplinary patient-focused approach for an appropriate management of CP. Registration: PROSPERO (CRD42021284790)(c) 2022 by United States Association for the Study of Pain, Inc.