Inappropriate benzodiazepine use in older adults and the risk of fracture

AIMS The Beers criteria for prescribing in elderly are well known and used for many drug utilization studies. We investigated the clinical value of the Beers criteria for benzodiazepine use, notably the association between inappropriate use and risk of fracture. METHODS We performed a nested case-control study within the Rotterdam Study, a population-based cohort study in 7983 elderly. The proportion of 'inappropriate' benzodiazepine use according to the Beers criteria was compared between fracture patients and controls. 'Inappropriate' use for elderly implies use of some long-acting benzodiazepines and some intermediate/short-acting ones exceeding a suggested maximum daily dose. Also, alternative criteria were applied to compare the risk of fracture. Cases were defined as persons with incident fracture between 1991 and 2002 who were current benzodiazepine users on the fracture date. Controls were matched on fracture date and were also current benzodiazepine users. RESULTS The risk of fracture in 'inappropriate' benzodiazepine users according to the Beers criteria was not significantly different from 'appropriate' users [odds ratio (OR) 1.07, 95% confidence interval (CI) 0.72, 1.60]. However, a significantly higher risk of fracture was found in 'high dose' users and a longer duration of use (14-90 days), irrespective of the type of benzodiazepine (OR 3.45, 95% CI 1.38, 8.59). CONCLUSIONS These findings suggest that inappropriate benzodiazepine use according to the Beers criteria is not associated with increased risk of fracture. Daily dose and longer duration of use (> 14 days) is associated with higher risk of fracture, irrespective of the type of benzodiazepine prescribed.