The impact of opioid prescribing guidelines on opioid dispensation: A systematic review and meta-analysis

Background Opioid prescribing guidelines for chronic noncancer pain (CNCP) aim to reduce opioid volume and dosage while addressing risks such as misuse, poisoning, and death. However, these guidelines may have spillover effects on patient populations beyond the intended scope.Aims This study aims to summarize the impact of prescribing guidelines on opioid use prevalence, incidence, and dosage across multiple jurisdictions and patient populations.Methods In October 2025, we systematically searched MEDLINE, Scopus, Web of Science, and PsycInfo for studies on the effects of opioid prescribing guidelines in adult populations. Primary outcomes included opioid use prevalence, incidence, dosage, and duration. We calculated study-level effect estimates using interrupted time series analyses and conducted meta-analyses with random effects models to estimate the pooled effect of the guidelines on the aforesaid outcomes.Results Of 190 records, 71 studies met inclusion criteria for meta-analysis. After guideline implementation, morphine milligram equivalent (MME) dosage per person and prescription duration decreased annually by 10.4% (95% confidence interval [CI] −19.2% to −0.6%) and 5.6% (95% CI −8.1% to −3.0%), respectively, among patients with CNCP. In the general population, MME dosage per person decreased annually by 7.6% (95% CI −11.3% to −3.7%), whereas duration remained stable over time (−1.4%; 95% CI −6.5% to 4.0%). Following guideline implementation, declines in prevalence, dosage, and duration were also observed in patients living with cancer or treated for acute pain.Conclusion Guidelines reduced opioid prescribing for CNCP. Future research is needed to examine whether and to what extent similar changes occurred among other patient populations.