Misuse of benzodiazepines: prevalence and impact in an inpatient population with psychiatric disorders.

Aims Use and misuse of benzodiazepine might be very prevalent in patients with acute psychiatric symptoms, whereas they might be associated with specific adverse events in this population. The study investigated their prevalence in these patients. Secondary objectives were to identify risk factors for misuse of benzodiazepines, and its impact. Methods A cohort study was based on the hospital's electronic patient records and conducted in patients aged 18 years and over and admitted to a psychiatric hospital. They were followed up for 84 days or until the end of hospitalisation. Four variables of misuse were built: excessive duration of treatment, type of product, excessive dosage and concomitant benzodiazepines. Backward stepwise multivariate logistic regression analysis was used to assess risk factors for each misuse criterion, on the 1 hand, and impact of benzodiazepine misuse, on the other. Results In total, 511 psychiatric inpatients were included with 89.0% of them exposed to benzodiazepine. Discharge prescription included no benzodiazepine or a dosage lower than the maximum dosage prescribed during hospitalisation for 78.2% of patients exposed to benzodiazepine during their stay. Of benzodiazepine treatments, 31.4% were associated with at least 1 misuse criterion. Excessive dosage was associated with age >= 65 years (OR 11.57; 95% confidence interval 4.92-27.17), substance/alcohol use disorders (3.35; 95% confidence interval 1.70-6.62) and parenthood (0.49; 0.25-0.97). Some criteria of benzodiazepine misuse were associated with a higher frequency of adverse events occurring after treatment initiation. Conclusions Misuse of benzodiazepines is very common in inpatients with psychiatric disorders. These findings should alert clinicians to comply with clinical recommendations.