Study Examines Mortality Risk During and After Opioid Substitution Therapy
Substitution therapy with methadone or buprenorphine is associated with reduced mortality in individuals with opioid dependence, according to the results of a recent study.
For their study, researchers conducted a systematic review and meta-analysis of prospective or retrospective cohort studies involving participants with opioid dependence that reported death from all causes or overdose during and after opioid substitution treatment.
Overall, the researchers included 19 cohorts including 122,885 individuals treated with methadone and 15,831 treated with buprenorphine. In individuals taking methadone, all-cause mortality rates were 11.3 and 36.1 per 1000 person years for in and out of treatment, respectively. In pooled trend analysis, all-cause mortality dropped significantly over the first 4 weeks of methadone treatment and decreased gradually 2 weeks after leaving treatment. Overdose mortality rates progressed similarly.
In those taking buprenorphine, all-cause mortality rates were 4.3 and 9.5 in and out of treatment, respectively, and remained stable during induction and over the remaining time of replacement treatment. Overdose mortality rates were 1.4 and 4.6 in and out of buprenorphine treatment, respectively.
“Retention in methadone and buprenorphine treatment is associated with substantial reductions in the risk for all cause and overdose mortality in people dependent on opioids,” the researchers concluded.
“These findings are potentially important, but further research must be conducted to properly account for potential confounding and selection bias in comparisons of mortality risk between opioid substitution treatments, as well as throughout periods in and out of each treatment.”
—Michael Potts
Reference:
Sordo L, Barrio G, Bravo MJ, et al. Mortality risk during and after opioid substitution treatment: systematic review and meta-analysis of cohort studies [published online April 26, 2017]. BMJ. doi: doi.org/10.1136/bmj.j1550.