Benzodiazepines and the risk of urinary incontinence in frail older persons living in the community

Abstract

Objective: Urinary incontinence is a common problem among older persons living in different community settings. The multifactorial origin of urinary incontinence has been largely addressed, and many previous studies have identified several reversible factors associated with incontinence. The aim of this study was to estimate the risk of urinary incontinence associated with the use of oxidative or nonoxidative benzodiazepines.

Methods: We analyzed data from a large collaborative observational study group, the Italian Silver Network Home Care project, which collected data on patients admitted to home care programs (N = 4583). A total of 22 home health agencies participated in the project, which evaluated the implementation of the Minimum Data Set for Home Care instrument. The main outcomes measure was the prevalence of urinary incontinence and the association with benzodiazepine use.

Results: A total of 1475 individuals (21% of patients aged 60-74 years and 38% aged >or=75 years) reported urinary incontinence. Users of benzodiazepines had an increased risk of urinary incontinence of nearly 45% (odds ratio [OR], 1.44; 95% confidence interval [CI], 1.12-1.83). The risk seemed to be of greater magnitude for exposure to oxidative agents (adjusted OR, 1.47; 95% CI, 1.09-1.99) than to nonoxidative benzodiazepines (adjusted OR, 1.35; 95% CI, 0.93-1.96). Among the oxidative benzodiazepines, the effect mainly resulted from agents with a long elimination half-life (adjusted OR, 1.75; 95% CI, 1.13-2.72).

Conclusions: The metabolic pathway of the benzodiazepines is a good predictor of urinary incontinence. In frail elderly patients, oxidative benzodiazepines are potentially more harmful than nonoxidative agents. Among oxidative benzodiazepines, the best ones seem to be those with a short elimination half-life.