Objective: Exact information on drug use is important information at admittance to hospital departments. The aim of this study was to validate the information given in the referral regarding benzodiazepine use by analysis of serum samples.
Methods: A total of 241 patients were included at admittance to a geriatric psychiatry department. Information on use of benzodiazepines according to the referral was recorded, and serum samples were analysed for benzodiazepine drugs. The number of patients with incorrect information in the referral was calculated for each benzodiazepine.
Results: Information on benzodiazepine use was included in 60 % of patient referrals. However, serum analyses revealed the use of different or additional benzodiazepines compared with the referral information in 24 % of the patients. In 10 % of the patients, a benzodiazepine was detected despite no information on benzodiazepine use at all in the referral. For diazepam, 70 % of users were identified by serum analyses only, while this number was lower for the other benzodiazepines.
Conclusions: This study shows that benzodiazepine use is widespread in geriatric psychiatry, but that information about the use of these drugs is very often incorrect. This may have significant clinical consequences if symptoms caused by use or abrupt cessation of benzodiazepines are misinterpreted.