Identification of the simultaneous use of multiple hypnotics as a risk factor for falls in hospitalized patients by a matched case-control study

Aim: The risk of falls owing to simultaneous use of multiple hypnotics has not been clarified. The aim of this study was to assess the association between the simultaneous use of 2 hypnotics and the occurrence of falls in hospitalized patients. Methods: A matched case-control study was conducted at Tokyo Medical University Hospital in Tokyo, Japan, utilizing data from medical records. Cases were 434 hospitalized patients who experienced falls during their hospital stay between January 2016 and December 2016, and controls were 434 hospitalized patients without falls, individually matched by age, sex, and clinical department. The outcome was the occurrence of an in-hospital fall. The associations between the use of 1 hypnotic and falls, and between the use of 2 hypnotics and falls were assessed by conditional logistic regression analyses. The main multivariable conditional logistic regression model was adjusted for potential risk factors, including the use of other classes of psychotropics (antipsychotics, antidepressants, and anxiolytics), in addition to patient characteristics. Results: The main multivariable conditional logistic regression analyses showed that the simultaneous use of 2 hypnotics (odds ratio [OR] = 2.986; 95% confidence interval [CI], 1.041–8.567), but not the use of a single hypnotic (OR = 1.252; 95% CI, 0.843–1.859), was significantly associated with an increased OR of falls. Conclusion: The simultaneous use of 2 hypnotics is a risk factor for falls among hospitalized patients, whereas the use of a single hypnotic may not.