Exposure to opioid maintenance treatment reduces long‐term mortality

Abstract

Aims To (i) examine the predictors of mortality in a randomized study of methadone versus buprenorphine maintenance treatment; (ii) compare the survival experience of the randomized subject groups; and (iii) describe the causes of death. Design Ten‐year longitudinal follow‐up of mortality among participants in a randomized trial of methadone versus buprenorphine maintenance treatment. Setting Recruitment through three clinics for a randomized trial of buprenorphine versus methadone maintenance. Participants A total of 405 heroin‐dependent (DSM‐IV) participants aged 18 years and above who consented to participate in original study. Measurements Baseline data from original randomized study; dates and causes of death through data linkage with Births, Deaths and Marriages registries; and longitudinal treatment exposure via State health departments. Predictors of mortality examined through survival analysis. Findings There was an overall mortality rate of 8.84 deaths per 1000 person‐years of follow‐up and causes of death were comparable with the literature. Increased exposure to episodes of opioid treatment longer than 7 days reduced the risk of mortality; there was no differential mortality among methadone versus buprenorphine participants. More dependent, heavier users of heroin at baseline had a lower risk of death, and also higher exposure to opioid treatment. Older participants randomized to buprenorphine treatment had significantly improved survival. Aboriginal or Torres Strait Islander participants had a higher risk of death. Conclusions Increased exposure to opioid maintenance treatment reduces the risk of death in opioid‐dependent people. There was no differential reduction between buprenorphine and methadone. Previous studies suggesting differential effects may have been affected by biases in patient selection.