Abstract
BACKGROUND: We aimed to investigate the association between short- and long-term opioid use and long-term mortality in Korea. METHODS: In this population-based retrospective cohort study, data were obtained from the National Health Insurance Service of South Korea. The study included all adult individuals who were prescribed opioids in 2016. The control group comprised adults not prescribed opioids in 2016 selected using a 1:1 stratified random sampling technique. Participants were categorized into three groups: non-user, opioid 1-89 days user (short-term), and opioid ≥ 90 days user (long-term) groups. The primary endpoint in this study was 5-year all-cause mortality, evaluated from January 1, 2017 to December 31, 2021. RESULTS: In total, 4,556,606 adults were included in this study. Of these, 2,070,039 were prescribed opioids at least once. Specifically, 1,592,883 adult individuals were prescribed opioids for 1-89 days, while 477,156 adults were prescribed opioid for ≥ 90 days. In the multivariable Cox regression modelling, the opioid user group had a 28% (hazard ratio [HR], 1.28; 95% confidence interval [95% CI], 1.26-1.29; P < 0.001) higher risk of 5-year all-cause mortality than had the non-user group. Moreover, the opioid 1-89 days and opioid ≥ 90 days user groups had 15% (HR, 1.15; 95% CI, 1.14-1.17; P < 0.001) and 49% (HR, 1.49; 95% CI, 1.47-1.51; P < 0.001) higher risks of 5-year all-cause mortality than had the non-user group, respectively. CONCLUSION: Both short and long-term opioid prescriptions were associated with increased long-term mortality among the Korean adult population.