July 19, 2012
Tired?
Scientists have discovered another possible
benefit of a night of restful and
uninterrupted sleep. According to a new study
led by researchers at the Johns Hopkins
Bloomberg School of Public Health fragmented
or interrupted sleep could predict future
placement in a nursing home or assisted living
facility. The study is featured in the July
2012 issue of the Journal of the American
Geriatrics Society and outlines the
association between objectively measured sleep
and subsequent institutionalization among
older women.
"Sleep
disturbances are common in older people," said
Adam Spira, PhD, lead author of the study and
an assistant professor with the Bloomberg
School's Department of Mental Health. "Our
results show that in community-dwelling older
women, more fragmented sleep is associated
with a greater risk of being placed in a
nursing home or in a personal care home. We
found that, compared to women with the least
fragmented sleep, those who spent the most
time awake after first falling asleep had
about 3 times the odds of placement in a
nursing home. Individuals with the lowest
sleep efficiency—those who spent the smallest
proportion of their time in bed actually
sleeping—also had about 3 times the odds of
nursing home placement." The authors found
similar patterns of associations between
disturbed sleep and placement in personal care
homes, such as assisted-living facilities.
Sleep duration per se did not predict
placement in either of these settings.
According
to the Centers for Disease Control and
Prevention, insufficient sleep is associated
with a number of chronic diseases and
conditions—such as diabetes, cardiovascular
disease, obesity and depression. In addition,
insufficient sleep is associated with the
onset of many diseases and is responsible for
motor vehicle and machinery-related crashes.
Previous studies have also linked disturbed
sleep with disability in older adults and
impairment in activities of daily living and
mobility.
Using
a prospective cohort study, researchers
measured the sleep of women with a mean age of
83 years old from the Study of Osteoporotic
Fractures. Participants were asked to wear
actigraphs on their non-dominant wrists for at
least three days. These devices record
movement, and the resulting data can be used
to characterize patterns of sleep and wake.
Demographic information as well as place of
residence at initial interview and at 5-year
follow-up was also provided. Although several
prior studies had investigated the link
between sleep disturbance and nursing home
placement, those studies asked participants
questions about sleep rather than collecting
objective sleep data.
"Despite
the growing literature on sleep disturbance
and disability, prior to our research very
little was known about the association between
sleep disturbance in older adults and risk of
placement in long-term care facilities.
Greater sleep fragmentation is associated with
greater risk of placement in a nursing home or
personal care home 5 years later after
accounting for a number of potential
confounders," said Kristine Yaffe, MD, senior
author of the study, and professor of
Psychiatry, Neurology, and Epidemiology and
Biostatistics at the University of California,
San Francisco.
Spira
adds, "It's important to remember that this is
an observational study, so our findings cannot
demonstrate a conclusive causal link between
sleep disturbance and placement in long-term
care facilities. We need more research to
explain how sleep disturbance might lead to
this outcome, and whether interventions to
improve sleep might prevent it."
