The Use of Hypnotics and Mortality - A Population-Based Retrospective Cohort Study

BACKGROUND Sleep disorders, especially chronic insomnia, have become major health problem worldwide and, as a result, the use of hypnotics is steadily increasing. However, few studies with a large sample size and long-term observation have been conducted to investigate the relationship between specific hypnotics and mortality. METHODS We conducted this retrospective cohort study using data from the National Health Insurance Research Database in Taiwan. Information from claims data including basic characteristics, the use of hypnotics, and survival from 2000 to 2009 for 1,320,322 individuals were included. The use of hypnotics was divided into groups using the defined daily dose and the cumulative length of use. Hazard ratios (HRs) were calculated from a Cox proportional hazards model, with two different matching techniques to examine the associations. RESULTS Compared to the non-users, both users of benzodiazepines (HR = 1.81; 95% confidence interval [CI] = 1.78-1.85) and mixed users (HR = 1.44; 95% CI = 1.42-1.47) had a higher risk of death, whereas the users of other non-benzodiazepines users showed no differences. Zolpidem users (HR = 0.73; 95% CI = 0.71-0.75) exhibited a lower risk of mortality in the adjusted models. This pattern remained similar in both matching techniques. Secondary analysis indicated that zolpidem users had a reduced risk of major cause-specific mortality except cancer, and that this protective effect was dose-responsive, with those using for more than 1 year having the lowest risk. CONCLUSIONS The effects of different types of hypnotics on mortality were diverse in this large cohort with long-term follow-up based on representative claims data in Taiwan. The use of zolpidem was associated with a reduced risk of mortality.