Sleep disturbances and mortality: results from the Canadian Study of Health and Aging.
OBJECTIVE
To cross-validate, in a secondary analysis, the observation that daytime sleepiness is associated with an increased risk of death.


METHODS
Prospective cohort study.


METHODS
Canada, a nationally representative sample of people age 65 and older.


METHODS
Nine thousand and eight community-dwelling participants in the Canadian Study of Health and Aging.


METHODS



METHODS
self-reported sleep disturbances.


RESULTS
Cox hazard ratios (HRs) for death.


RESULTS
The unadjusted analysis showed a small increased risk of death from daytime sleepiness (HR = 1.89; 95% confidence interval (CI) = 1.44-2.46), but this finding did not persist in a multivariate model adjusted for age, depression, cognition, comorbid illness, and function.


CONCLUSIONS
Daytime sleepiness itself is not associated with an increased risk of death when other factors are taken into account. Daytime sleepiness may be a proxy for other morbid conditions and therefore for overall tiredness.
Rockwood
K
K
Division of Geriatric Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.
Davis
H S
HS
Merry
H R
HR
MacKnight
C
C
McDowell
I
I
D000203:Activities of Daily Living; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D002170:Canada / Q000453:epidemiology; D003072:Cognition Disorders / Q000150:complications; D015897:Comorbidity; D003863:Depression / Q000150:complications; D005221:Fatigue / Q000150:complications* / Q000453:epidemiology*; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D008403:Mass Screening; D009026:Mortality; D015999:Multivariate Analysis; D011159:Population Surveillance; D015995:Prevalence; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012893:Sleep Wake Disorders / Q000150:complications* / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D016019:Survival Analysis