Mortality associated with benzodiazepines and benzodiazepine-related drugs among community-dwelling older people in Finland: a population-based retrospective cohort study

Objective: To investigate the association between the use of benzodiazepines (BDZs) and BDZ-related drugs and mortality among community-dwelling people aged 65 years and older in Finland. 

Method: This was a population-based retrospective cohort study. Records of all reimbursed drugs purchased by all 2224 residents of Leppävirta, Finland, aged 65 years and older in 2000 were extracted from the Finnish National Prescription Register. Diagnostic data were extracted from the Special Reimbursement Register. All-cause mortality was assessed after 9 years using national registers. Cox proportional hazards models were used to compute unadjusted and adjusted hazard ratios (HRs) and 95% confidence intervals for mortality among prevalent users of BDZs and BDZ-related drugs in 2000 (n = 325), compared with nonusers of BDZs and BDZ-related drugs between 2000 and 2008 (n = 1520). 

Results: BDZs and BDZ-related drugs were used by 325 out of the 2224 residents (14.6%) in 2000. The 9-year mortality was 50.2% among BDZ and BDZ-related drug users in 2000 and 36.3% among BDZ and BDZ-related drug nonusers between 2000 and 2008 (HR 1.53; 95% CI 1.28 to 1.82). After adjusting for baseline age, sex, antipsychotic drug use, and diagnostic confounders, the HR was 1.01 (95% CI 0.84 to 1.21). 

Conclusions: Use of BDZs and BDZ-related drugs was associated with an increased mortality hazard in unadjusted analyses. However, after adjusting for age, sex, antipsychotic drug use, and diagnostic confounders, the use of BDZs and BDZ-related drugs was not associated with excess mortality.