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 Leppavirta, 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. Can J Psychiatry. 2011;56(6):377-381. Clinical Implications * Adverse drug events associated with BDZs are well documented. However, there are conflicting data about mortality hazards. * In contrast to recent findings from a Canadian study, BDZs and BDZ-related drugs were not associated with excess mortality after adjusting for baseline differences in age, sex, antipsychotic drug use, and diagnoses. * While BDZs and BDZ-related drugs were not associated with excess mortality, clinicians should maintain a judicious approach when prescribing BDZs and BDZ-related drugs for older people. Limitations * The study sample was drawn from a single municipality in Finland and, therefore, may not be generalizable to other populations. * Only large BDZ and BDZ-related drug pack sizes were reimbursed and included in the Finnish National Prescription Register in 2000. This means BDZ and BDZ-related drug use may have been underestimated. * Differences in BDZ and BDZ-related drug dose, frequency, and duration of use were not evaluated. Key Words: hypnotics and sedatives, benzodiazepines, mortality, aged, pharmacoepidemiology Abbreviations AD antidepressant ATC Anatomical Therapeutic Chemical BDZ benzodiazepine FNPR Finnish National Prescription Register HR hazard ratio SII Social Insurance Institution of Finland BDZs are among the most frequently used drugs among community-dwelling older people in Europe and North America.1,2 However, use of BDZs for insomnia may not improve sleep quality in older people.3 BDZs have been associated with cognitive impairment, depressive symptoms, poor physical function, falls, and fractures.4-7 The responsible prescribing of BDZs in psychiatric disorders has recently been debated.8 Research into the association between BDZ use and mortality has been inconsistent.9 A recent study10 using data from the Canadian National Population Survey reported that anxiolytic and hypnotic drug use was associated with a small but significant increase in mortality. The objective of our study was to investigate the association between use of BDZs and BDZ-related drugs and mortality among community-dwelling people aged 65 years and older in Finland. Methods Data Sources The study protocol was approved by the SII. …