Medication use as a risk factor for inpatient falls in an acute care hospital: a case-crossover study.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Benzodiazepines, antidepressants, antipsychotic agents, anti-arrhythmic agents, opioid analgesics and antihypertensive agents including α-receptor antagonists and β-receptor antagonists, but not angiotensin II receptor antagonists, have been implicated as risk factors for falls among community dwelling elderly people, and those in aged care hospitals and nursing homes. WHAT THIS STUDY ADDS • Using a case-crossover design, the study's findings provide the first evidence suggesting that newly initiating treatment using an angiotensin II receptor antagonist, candesartan, or etizolam, biperiden and zopiclone may be potential risk factors for falls in acute hospitals. AIMS The present study aimed to evaluate the associations between medication use and falls and to identify high risk medications that acted as a trigger for the onset of falls in an acute care hospital setting. METHODS We applied a case-crossover design wherein cases served as their own controls and comparisons were made within each participant. The 3-day period (days 0 to −2) and the 3-day periods (days −6 to −8, days −9 to −11 and days −12 to −14) before the fall event were defined as the case period and the control periods, respectively. Exposures to medications were compared between the case and control periods. Odds ratios (OR) and 95% confidence intervals (CI) for the onset of falls with respect to medication use were computed using conditional logistic regression analyses. RESULTS A total of 349 inpatients who fell during their hospitalization were recorded on incident report forms between March 2003 and August 2005. The initial use of antihypertensive, antiparkinsonian, anti-anxiety and hypnotic agents as medication classes was significantly associated with an increased risk of falls, and these ORs (95% CI) were 8.42 (3.12, 22.72), 4.18 (1.75, 10.02), 3.25 (1.62, 6.50) and 2.44 (1.32, 4.51), respectively. The initial use of candesartan, etizolam, biperiden and zopiclone was also identified as a potential risk factor for falls. CONCLUSIONS Medical professionals should be aware of the possibility that starting a new medication such as an antihypertensive agent, including candesartan, and antiparkinsonian, anti-anxiety and hypnotic agents, may act as a trigger for the onset of a fall. [ABSTRACT FROM AUTHOR]