TY - JOUR
T1 - Investigation of the relationship between sleep duration, all-cause mortality, and preexisting disease
AU - Magee, Christopher A.
AU - Holliday, Elizabeth G.
AU - Attia, John
AU - Kritharides, Leonard
AU - Banks, Emily
PY - 2013/7
Y1 - 2013/7
N2 - Objective: To examine the relationship between sleep duration and mortality and to quantify the likely impact of residual confounding due to poor health status on any observed association. Methods: The sample included 227,815 Australian adults aged 45. years and older recruited from 2006-2009 (the 45 and Up Study). Sleep duration and relevant covariates (e.g., health status, demographic factors) were assessed through a self-report questionnaire. These data were linked with mortality data from the New South Wales Registry of Births, Deaths, and Marriages up to December 2010 (mean follow-up period, 2.8. y). Cox proportional hazards models examined the relationship between sleep duration and all-cause mortality adjusting for relevant sociodemographic covariates (e.g., age, gender, marital status), with further stratification by baseline health status based on physical functioning and preexisting disease. Results: The adjusted mortality risk was significantly higher in individuals reporting <6. hours of sleep (hazard ratio [HR], 1.13[1.01-1.25]) and ≥10. hours of sleep (HR, 1.26[1.16-1.36]), compared to those reporting 7. hours of sleep per night. These associations differed by baseline health status (p[interaction]. = 0.026) such that there was no significant relationship of sleep duration to mortality in those with good health at baseline. Conclusion: Following careful prospective controlling for baseline health, mortality risk does not significantly vary according to sleep duration. Previous findings suggesting a relationship between sleep duration and mortality could be affected by residual confounding by poor preexisting health, as reflected by a combination of preexisting illnesses and functional limitations.
AB - Objective: To examine the relationship between sleep duration and mortality and to quantify the likely impact of residual confounding due to poor health status on any observed association. Methods: The sample included 227,815 Australian adults aged 45. years and older recruited from 2006-2009 (the 45 and Up Study). Sleep duration and relevant covariates (e.g., health status, demographic factors) were assessed through a self-report questionnaire. These data were linked with mortality data from the New South Wales Registry of Births, Deaths, and Marriages up to December 2010 (mean follow-up period, 2.8. y). Cox proportional hazards models examined the relationship between sleep duration and all-cause mortality adjusting for relevant sociodemographic covariates (e.g., age, gender, marital status), with further stratification by baseline health status based on physical functioning and preexisting disease. Results: The adjusted mortality risk was significantly higher in individuals reporting <6. hours of sleep (hazard ratio [HR], 1.13[1.01-1.25]) and ≥10. hours of sleep (HR, 1.26[1.16-1.36]), compared to those reporting 7. hours of sleep per night. These associations differed by baseline health status (p[interaction]. = 0.026) such that there was no significant relationship of sleep duration to mortality in those with good health at baseline. Conclusion: Following careful prospective controlling for baseline health, mortality risk does not significantly vary according to sleep duration. Previous findings suggesting a relationship between sleep duration and mortality could be affected by residual confounding by poor preexisting health, as reflected by a combination of preexisting illnesses and functional limitations.
KW - Health status
KW - Mortality
KW - Preexisting disease
KW - Prospective
KW - Residual confounding
KW - Sleep duration
UR - http://www.scopus.com/inward/record.url?scp=84880132876&partnerID=8YFLogxK
U2 - 10.1016/j.sleep.2013.02.002
DO - 10.1016/j.sleep.2013.02.002
M3 - Article
SN - 1389-9457
VL - 14
SP - 591
EP - 596
JO - Sleep Medicine
JF - Sleep Medicine
IS - 7
ER -