• Thank goodness TV’s not all bad

    As a major consumer of television and computers, I’m constantly dismayed at how every single study seems to find that their use is linked to an enormous numbers of bad things. “Screen time” makes you fat, gives you ADHD, makes you stupid, keeps you from sleeping, etc.* So it was comforting to see at least one study that shows it doesn’t kill you:

    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 7350 adults aged [greater than or equal to]20 years who participated in the National Health and Nutrition Examination Survey during 1999 to 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 one hour per day, 16.4% did so for 1 hour, 27.8% for 2 hours, 18.7% for 3 hours, 10.9% for 4 hours, and 13.5% for 5 or more hours. 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.

    I will grant you I’m not unbiased here. I love TV, I love computers, and I love video games. On the whole, I think consuming amounts of technology that would stagger mere mortals has not hurt me too much; I think I’ve turned out OK. But I agree that there should be limits. Although I’m more permissive with my kids than many of my friends are with theirs, my children are not allowed to spend too much time playing video games and watching TV. They’re turning out pretty well, too.

    I will also grant you that my wife and I spend an enormous amount of time with our children, and they have a number of advantages that other children might not. But that’s the point. It’s hard to determine which of these things is causal. It may be that there are other factors that are correlated with lots of TV time that may make kids or people worse off. Perhaps parents who let their kids watch enormous amounts of TV are more likely to be bad parents. Perhaps parents who let their kids watch enormous amounts of TV are working three jobs, struggling to make ends meet, and can’t play with their kids as much as they would like. Perhaps parents who let their kids watch enormous amounts of TV are depressed or sick. There are any number of scenarios where kids who have it harder are more likely to watch TV, without it being the TV that’s hurting them.

    Many of the studies account for that as best they can. But the media likes to run around extrapolating a small statistically significant correlation into headlines like “TV WILL KILL YOU!” The sensationalism is pretty staggering. This leads to a publication bias, where results that are likely to shock and garner headlines are more likely to get accepted and printed.

    So I’m glad to see a negative study get published. I bet you didn’t know about this study, though. It was published last week with almost no fanfare, and I doubt you will see any news stories on it. When it comes to science, I fear the media isn’t nearly as fair and balanced as many think they are.

    *Full disclosure: A number of these studies have been published by friends, colleagues, and even mentors. They know how upset I am that they keep attacking the things I love, but that doesn’t seem to be stopping them.

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    • Can’t one make the same arguments with respect to fast/junk food and obesity?

    • The best part of this post

      Dr. Carroll “I love TV”.

      That should be logged into “the things doctors never to patients say but do”

    • A somewhat similar result can be found in a FTC Staff Report that came out in 2007 on television advertising and obesity among children. It found that advertising exposure was down, though it’s for more sedentary entertainment. Food advertising is non-negligible but hasn’t risen relative to 1977. It also finds that the mix of foods advertised haven’t changed much. Overall, there appears to be little evidence that television advertising is responsible for the rise in childhood obesity.

      Source: Holt, Debra J., Pauline M. Ippolito, Debra M. Desrochers, and Christopher R. Kelley, “Children’s Exposure to TV Advertising in 1977 and 2004: Information for the Obesity Debate,” Federal Trade Commission Staff Report, June 1, 2007, available at http://www.ftc.gov/os/2007/06/cabecolor.pdf.