Mortality and negative outcomes of opioid use and opioid use disorder: a 6-year follow-up study

There is a paucity of data on outcomes of opioid use disorder (OUD) from low- and middle-income countries. We aimed to investigate the mortality as well as negative social and health outcomes in a 6-year follow-up study of a cohort of individuals with opioid use, including those with OUD, in Iran.

Participants with opioid use initially interviewed in late 2011 in the Iranian National Mental Health Survey (IranMHS)-a household survey of 15-64-year-old population-were followed-up in early 2018.

All respondents (n = 236) who had reported use of any opioids at least five times during the 12-month period prior to the index interview were included in the study.

Composite International Diagnostic Interview (CIDI) version 2.1 was used for assessment of opioid use and OUD at baseline. Vital status in the follow-up was ascertained through contact with participants/informants, primarily via telephone calls and also through the death registration systems. Weighted incidence rates of negative consequences of opioid use (e.g. incarceration, suicide attempts, violent behavior) were estimated for those who were interviewed.

Seven (3.3%) of the 236 participants with opioid use including four (3.1%) of the 136 with OUD had died by the time of the follow-up interview, resulting in death rates of 0.49 [95% confidence interval (CI) = 0.21-1.38] and 0.53 (95% CI = 0.16-2.62) per 100 person-years, respectively. Overall, 35.0% of participants with opioid use and 44.0% of those with OUD among the 145 individuals interviewed at follow-up experienced non-fatal serious adverse outcomes.

In Iran, opioid use and opioid use disorder are associated with increased mortality and other adverse outcomes.