Benzodiazepine Use and Long-Term Mortality in South Korean Adult Population: A Cohort Study

Studies have reported mixed results on the association between benzodiazepine use and mortality. Here, we investigated whether benzodiazepine use is associated with a higher risk of 5-year all-cause mortality, and examined the association between benzodiazepine use and 5-year disease-specific mortality.

In this population-based cohort study, a nationally representative sample cohort in South Korea was examined. In 2010, benzodiazepine users were defined as individuals prescribed benzodiazepine continuously over 30 days for regular administration, and all other subjects were included in the control group. The primary endpoint was 5-year all-cause mortality, evaluated from 2011 to 2015. Propensity score (PS) matching and time-dependent Cox regression were performed for statistical analysis, which included benzodiazepine use during 2011-2015 as a time-dependent variable.

A total of 822414 adult individuals were included in the final analysis, and the all-cause 5-year mortality was recorded in 20991 individuals (2.7%). The benzodiazepine group included 30837 patients and the control group comprised 791377 patients. After PS matching, 61672 individuals (30836 in each group) were included in the final analysis. After PS matching, the 5-year all-cause mortality in the benzodiazepine group was 10.0% (3082/30836), whereas that in the control group was 9.4% (2893/30836). In time-dependent Cox regression analysis of the PS-matched cohort, the benzodiazepine group showed 1.15-fold higher 5-year all-cause mortality (hazard ratio: 1.15, 95% confidence interval: 1.09-1.22; p<0.001) compared to the control group.

Benzodiazepine use was associated with increased 5-year all-cause mortality in the South Korean adult population. Further studies are needed to confirm these findings.