Prevalence of Comorbid Substance Use Disorders among People with Opioid Use Disorder: A Systematic Review & Meta-Analysis


Author: Thomas Santo Jr, Gabrielle Campbell, Natasa Gisev, Samantha Colledge-Frisby, Jack Wilson, Brodie Clark, Lucy Thi Tran, Louisa Degenhardt

Theme: Epidemiology & Public Health Research Year: 2023

Background:
Among people with OUD, comorbid substance use disorders (SUDs) increase the risk of poor clinical outcomes, including overdose and mortality. However, no study has synthesized evidence on the prevalence of any comorbid SUD among people with OUD. Therefore, we conducted the first systematic review and meta-analysis to estimate the prevalence of non-opioid SUDs among people with OUD. We also examined if each estimate varied according to sample characteristics and study methodology.

Methods:
We searched Embase, PsycInfo, & MEDLINE from 1990 to 2022 for studies of people with OUD that evaluated the prevalence of one or more comorbid non-opioid SUD according to validated diagnostic criteria (e.g., International Classification of Diseases). We used random-effects meta-analyses with 95% Confidence Intervals (95%CIs) to pool current and lifetime estimates of comorbid SUDs among people with OUD. Additionally, stratified meta-analyses and meta-regressions were used to examine heterogeneity in prevalence estimates by pre-specified variables.

Results:
Of the 39,120 publications identified, we included data from 177 studies and 66,271 participants with OUD in at least one pooled estimate. The prevalence of any current SUD was 57.6% (95%CI 45.8–69.5%), alcohol use disorder was 29.0% (95%CI 25.4–32.7%), cannabis use disorder was 22.8% (95%CI 16.7–28.8%), cocaine use disorder was 29.6% (95%CI 20.3–38.8%), methamphetamine use disorder was 10.3% (95%CI 7.1–13.5%), and sedative use disorder was 17.4% (95%CI 13.4–21.3%). Prevalence estimates varied significantly by sample characteristics and methodological factors, including sex, geographic region and injecting drug use status.

Conclusion:
This systematic review and meta-analysis provides robust evidence to confirm the high prevalence of non-opioid SUDs among individuals with OUD. The findings emphasize the need for tailored, integrated care addressing both OUD and comorbid SUDs. These prevalence estimates can inform OUD treatment, overdose prevention, harm reduction, and tailored strategies for people with OUD and specific subpopulations.

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