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Published on: January 7, 2013
Sedentary behaviour and life expectancy in the USA: a cause-deleted life table analysis
Peter T Katzmarzyk1, I-Min Lee
1Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA.
Objectives:
To determine the impact of sitting and television viewing on life expectancy in the USA.
Design:
Prevalence-based cause-deleted life table analysis.
Setting:
Summary RRs of all-cause mortality associated with sitting and television viewing were obtained from a meta-analysis of available prospective cohort studies. Prevalences of sitting and television viewing were obtained from the US National Health and Nutrition Examination Survey.
Primary Outcome Measure:
Life expectancy at birth.
Results:
The estimated gains in life expectancy in the US population were 2.00 years for reducing excessive sitting to <3 h/day and a gain of 1.38 years from reducing excessive television viewing to <2 h/day. The lower and upper limits from a sensitivity analysis that involved simultaneously varying the estimates of RR (using the upper and lower bounds of the 95% CI) and the prevalence of television viewing (±20%) were 1.39 and 2.69 years for sitting and 0.48 and 2.51 years for television viewing, respectively.
Conclusion:
Reducing sedentary behaviours such as sitting and television viewing may have the potential to increase life expectancy in the USA.
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