Risk of in-hospital falls among medications commonly used for insomnia in hospitalized patients

Abstract

Study objectives: To investigate the risk of in-hospital falls among patients receiving medications commonly used for insomnia in the hospital setting.

Methods: Retrospective cohort study of all adult hospitalizations to a large academic medical center from January, 2007 to July, 2013. We excluded patients admitted for a primary psychiatric disorder. Medication exposures of interest, defined by pharmacy charges, included benzodiazepines, non-benzodiazepine benzodiazepine receptor agonists, trazodone, atypical antipsychotics, and diphenhydramine. In-hospital falls were ascertained from an online patient safety reporting system.

Results: Among the 225,498 hospitalizations (median age = 57 years; 57.9% female) in our cohort, 84,911 (37.7%) had exposure to at least one of the five medication classes of interest; benzodiazepines were the most commonly used (23.5%), followed by diphenhydramine (8.3%), trazodone (6.6%), benzodiazepine receptor agonists (6.4%), and atypical antipsychotics (6.3%). A fall occurred in 2,427 hospitalizations (1.1%). The rate of falls per 1,000 hospital days was greater among hospitalizations with exposure to each of the medications of interest, compared to unexposed: 3.6 versus 1.7 for benzodiazepines (adjusted hazard ratio [aHR] 1.8, 95%CI 1.6-1.9); 5.4 versus 1.8 for atypical antipsychotics (aHR 1.6, 95%CI 1.4-1.8); 3.0 versus 2.0 for benzodiazepine receptor agonists (aHR 1.5, 95%CI 1.3-1.8); 3.3 versus 2.0 for trazodone (aHR 1.2, 95%CI 1.1-1.5); and 2.5 versus 2.0 for diphenhydramine (aHR 1.2, 95%CI 1.03-1.5).

Conclusions: In this large cohort of hospitalizations at an academic medical center, we found an association between each of the sedating medications examined and in-hospital falls. Benzodiazepines, benzodiazepine receptor agonists, and atypical antipsychotics had the strongest associations.

Keywords: falls; hospitalization; insomnia; pharmacoepidemiology; sedatives.