Additionally, the use of sleep medications does not appear to influence the association between sleep and risk of falling.
"Falls pose a major health risk among older adults and are a leading cause of mortality [death], morbidity [illness] and premature nursing home placement," according to background information in the article. About one-third of adults older than age 65 experience falls each year. Insomnia and disturbed sleep as well as the use of benzodiazepines (hypnotic medications to treat insomnia) are increasingly common in older adults. "It is not established whether it is poor sleep or medications used to treat sleep disturbances that explain the increased risk of falls in those who are prescribed such medications."
Katie L. Stone, Ph.D., of the California Pacific Medical Center Research Institute, San Francisco, and colleagues used wrist actigraphies (watch-like devices) and sleep diaries to measure sleep, sleep efficiency (the percentage of time in bed spent sleeping) and frequency of falls in 2,978 women age 70 and older. Questionnaires were used to determine demographic information and use of benzodiazepines.
Participants averaged 6.8 hours of sleep per night and spent an average 77.2 minutes awake after initial sleep onset. The average number of falls one year after the collection of sleep data was 0.84. "A total of 549 women (18.4 percent) had two or more falls during the year after the sleep assessments," the authors write.
The risk of having two or more falls during the following year was higher for women who slept five hours or less per night compared with women who slept more than seven to eight hours per night. Compared with those with a sleep efficiency of 70 percent or higher, those with a sleep efficiency of less than 70 percent were 1.36 times more likely to experience a fall. Similarly, women with greater wake time after sleep onset (120 minutes or more) were 1.33 times more likely to fall than those who spent less than 120 minutes awake after sleep onset.
"In all, 214 subjects (7.2 percent) reported current use of benzodiazepines," the authors write. "Use of any benzodiazepine (short and long combined) was associated with a 1.34-fold increase in risk of falls, whereas short- and long-acting benzodiazepine use was associated with an increased odds of 1.43 and 1.18, respectively."
"Future studies, in particular randomized trials, are needed to determine the effects of newer pharmaceutical interventions for insomnia (e.g., benzodiazepine receptor agonists) or cognitive behavioral therapy for insomnia on risk of falls," the authors conclude. "In addition, future studies using comprehensive and objective measures of sleep should examine the interrelationships between specific sleep characteristics (e.g., sleep-related breathing disorder, hypoxia and measures of sleep duration and fragmentation) to determine if these disorders contribute independently toward risk of falls."