Regular prescriptions for benzodiazepines: a cross-sectional study of outpatients at a university hospital.

OBJECTIVE To investigate 1) the patterns of regular prescriptions for benzodiazepines among department clinics in a university teaching hospital, 2) the effects of patient's characteristics on regular benzodiazepine prescriptions, and 3) the patterns of benzodiazepine prescriptions among department clinics from the perspective of pharmacological half-life. PATIENTS Patients were 22,099 outpatients (51% female; mean age: 56 years) who were prescribed any drug three or more times. METHODS Cross-sectional study of patient-based data (July 2002 to August 2003) from the database of a computer ordering system at a university hospital. The patterns of regular prescriptions for benzodiazepines were compared among the clinical departments (i.e., Internal Medicine, Psychiatry, and Others). A logistic regression model was used to assess the effects of patient gender and age, and the clinic visited on the issuing of regular prescriptions for benzodiazepines. RESULTS Regular benzodiazepine users were 3,204 (14.5%). Benzodiazepines were more likely to be prescribed for women (61.3%) than for men and were prescribed most often by psychiatrists (31.7%), followed by internists (20.1%). Multivairate logistic regression model showed that being female and elderly, and being prescribed by a psychiatrist were significantly associated with regular benzodiazepine prescriptions. With regard to the pharmacological half-life, internists were more likely to prescribe short half-life benzodiazepines than were psychiatrists (p < 0.001). CONCLUSION A large number of outpatients at a Japanese university hospital appeared to be maintained on a regular supply of benzodiazepine drugs. Educational programs are needed to promote the rational prescribing of benzodiazepines.