Benzodiazepines and hip fractures in elderly people: case-control study

ObjectiveTo determine whether benzodiazepines are associated with an increased risk of hip fracture.DesignCase-control study.ParticipantsAll incident cases of hip fracture not related to traffic accidents or cancer in patients over 65 years of age. 245 cases were matched to 817 controls.SettingEmergency department of a university hospital.ResultsThe use of benzodiazepines as determined from questionnaires, medical records, or plasma samples at admission to hospital was not associated with an increased risk of hip fracture (odds ratio 0.9, 95% confidence interval 0.5 to 1.5). Hip fracture was, however, associated with the use of two or more benzodiazepines, as determined from questionnaires or medical records but not from plasma samples. Of the individual drugs, only lorazepam was significantly associated with an increased risk of hip fracture (1.8, 1.1 to 3.1).ConclusionExcept for lorazepam, the presence of benzodiazepines in plasma was not associated with an increased risk of hip fracture. The method used to ascertain exposure could influence the results of case-control studies.

What is already known on this topic

Benzodiazepines increase the risk of elderly people falling in a dose dependent wayTheir role in hip fracture remains disputed, with increased risk sometimes attributed to drugs with a longer half life or those used to induce sleep

What this study adds

Benzodiazepines were not associated with hip fracture either as a group or according to half life or to characterisation as hypnotic or anxiolyticPatients using two or more benzodiazepines may be at higher riskPatients using lorazepam or certain other benzodiazepines may also be at a higher risk of fracture