Benzodiazepine use and risk of community-acquired pneumonia in a population-based cohort study from north-eastern Spain

© The Author(s) 2017. Bac kground: Benzodiazepine (Bz) exposure has been identified as a risk factor of community-acquired pneumonia (CAP) in some observational studies, but this remains controversial. This study was designed to quantify the risk of CAP associated with treatment with Bz. Met hods: All individuals ⩾14 years of age registered in any of 3 primary health care providers in our area between January 2011 and May 2013 were included in the study. This resulted in a population of 51 912 individuals who contributed to a total of 1 496 680 person-months of observation. Previously anonymized data for each participant were obtained from their personal health records and the official prescription database. The primary outcome measures were the incidence of CAP during the study period and the relative risk (RR) that could be attributed to Bz exposure. Results: A total of 696 CAP cases were diagnosed. Incidence density was 12.4 cases per 1000 person-years in individuals exposed to Bz and 4.51 cases per 1000 person-years in those who were not. Benzodiazepine exposure increased the risk of CAP in the whole population (RR: 2.76, 95% confidence interval: 2.35-3.25) and in all the evaluated subgroups. Stratified analysis showed an interaction only with age (RR: 2.99 in patients under 65 years and 1.78 in those aged 65 or older). Benzodiazepine exposure was associated with an excess 0.79 cases of CAP per 100 person-years. Conclusions: Benzodiazepine exposure increases the risk of CAP. Given the clinical relevance of CAP, prescribers should be aware of this potentially preventable risk and consider it while newly prescribing Bz.