Combined television viewing and computer use and mortality from all-causes and diseases of the circulatory system among adults in the United States

Background: Watching television and using a computer are increasingly common sedentary behaviors. Whether or not prolonged screen time increases the risk for mortality remains uncertain. Methods: Mortality for 7,350 adults aged >= 20 years who participated in the National Health and Nutrition Examination Survey during 1999-2002 and were followed through 2006 was examined. Participants were asked a single question about the amount of time they spent watching television or videos or using a computer during the past 30 days. Results: During a median follow-up of 5.8 years, 542 participants died. At baseline, 12.7% of participants reported watching television or using a computer less than 1 h per day, 16.4% did so for 1 h, 27.8% for 2 h, 18.7% for 3 h, 10.9% for 4 h, and 13.5% for 5 or more h. After extensive adjustment, the hazard ratio for all-cause mortality for the top category of exposure was 1.30 (95% confidence interval: 0.82, 2.05). No significant trend across categories of exposure was noted. The amount of screen time was also not significantly related to mortality from diseases of the circulatory system. Conclusions: In the present study, screen time did not significantly predict mortality from all-causes and diseases of the circulatory system.