Bahji A, et al. - Among opioid-dependent persons, researchers analyzed the connection between methadone and buprenorphine with cause-specific mortality. In total, 32 cohort studies representing 150,235 candidates, 805,423.6 person-years, and 9,112 deaths met the criteria for eligibility. Compared with buprenorphine cohorts, crude mortality rates were substantially higher among methadone cohorts. Methadone relative to buprenorphine led to substantially higher relative risk reduction when time in-treatment was compared with time out-of-treatment. In addition, the first 4 weeks of treatment displayed the greatest mortality reduction. Mortality measures were substantially heterogeneous and were significantly variable by country, region, and by the nature of the treatment provider. According to this systematic review and meta-analysis, precautions are required for the safer implementation of opioid agonist treatment, including baseline assessments of opioid tolerance, continuous monitoring during the initiation process, patient awareness on the risk of overdose, and coordination within healthcare services.