Objective: To review studies examining the proportion of people with chronic noncancer pain who report consuming opioids and characteristics associated with their use.
Design: Systematic review.
Methods: We searched databases from inception to February 8, 2020, and conducted citation tracking. We included observational studies reporting the proportion of adults with chronic noncancer pain who used opioid analgesics. Opioids were categorized as weak (e.g., codeine) or strong (e.g., oxycodone). Study risk of bias was assessed, and Grading of Recommendations Assessment, Development and Evaluations provided a summary of the overall quality. Results were pooled using a random-effects model. Meta-regression determined factors associated with opioid use.
Results: Sixty studies (N=3,961,739) reported data on opioid use in people with chronic noncancer pain from 1990 to 2017. Of these 46, 77% had moderate risk of bias. Opioid use was reported by 26.8% (95% confidence interval [CI], 23.1-30.8; moderate-quality evidence) of people with chronic noncancer pain. The use of weak opioids (17.3%; 95% CI 11.9-24.4; moderate-quality evidence) was more common than the use of strong opioids (9.8%; 95% CI, 6.8-14.0; low-quality evidence). Meta-regression determined that opioid use was associated with geographic region (P=0.02; lower in Europe than North America), but not sampling year (P=0.77), setting (P=0.06), diagnosis (P=0.34), or disclosure of funding (P=0.77).
Conclusions: Our review summarized data from over 3.9 million people with chronic noncancer pain reporting their opioid use. Between 1990 and 2017, one-quarter of people with chronic noncancer pain reported taking opioids, and this proportion did not change over time.
Keywords: Chronic Pain; Systematic Review; Opioid Analgesics.
© The Author(s) 2020. Published by Oxford University Press on behalf of the American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.