Pain in people seeking and receiving opioid agonist treatment: A systematic review and meta-analysis of prevalence and correlates.

BACKGROUND AND AIMS

People with opioid use disorder (OUD) commonly experience pain including chronic pain. Despite the high prevalence, few studies have systematically examined the prevalence and correlates of pain among people seeking or receiving opioid agonist treatment (OAT) for OUD. This review aimed to determine the prevalence of pain in this population globally, and estimate the association between chronic pain and other demographic and clinical characteristics.

METHODS

Electronic searches were conducted in three databases (Medline, Embase and PsycINFO) from the inception until October 2022. Eligible studies reported prevalence rates of current and/or chronic pain. Meta-analyses examining the main prevalence estimates were conducted by Stata SE 18.0, and comorbid clinical conditions were analysed by Review Manager 5.4.

RESULTS

Fifty-six studies (n participants = 35 267) from sixty-seven publications were included. Prevalence estimates of current and chronic pain were reported in 27 (48.2%) and 40 studies (71.4%), respectively. Most studies were conducted in North America (71.4%, n = 40) and used cross-sectional designs (64.3%, n = 36). Meta-analyses revealed a pooled prevalence of 60.0% (95% confidence interval [CI]: 52.0-68.0) for current pain and 44.0% [95% CI: 40.0-49.0] for chronic pain. Chronic pain was positively associated with older age (mean deviation of mean age: 2.39 years, 95% CI: 1.40-3.37; I = 43%), unemployment (odds ratio [OR] = 0.57, 95% CI: 0.42-0.76; I = 78%), more severe mental health symptoms (e.g. more severe depression (standardised mean difference [SMD] of mean scores: 0.45, 95% CI: 0.20-0.70; I = 48%) and anxiety symptoms (SMD: 0.52, 95% CI: 0.17-0.88; I = 67%), and hepatitis C (OR = 1.41, 95% CI: 1.03-1.94; I = 0%). No association was observed between chronic pain and the onset and type of OAT, geographic location, study design, survey year, participant age or use of specific pain assessment tools.

CONCLUSIONS

There appears to be a high prevalence of pain among people seeking or receiving opioid agonist treatment for opioid use disorder compared with the general population, with positive associations for older age, unemployment, hepatitis C and the severity of some mental health symptoms.