Headline writers, health-beat journalists, editors embarrass themselves en masse

You'd think reading the health sections of our mass media would go some way towards prolonging your life. But you should think twice. A horrible disease is being spread by health reporters. Their crime is spreading false information in an attempt to attract eyeballs.

Note the most read article on Yahoo! News the other day:

A lot of people clicked on the link that proclaimed: "Too much TV may take years off your life."

The article dutifully reported the findings of an Australian study: that "people who averaged six hours a day of TV lived, on average, nearly five years less than people who watched no TV." Also, that "For every hour of television watched after age 25, lifespan fell by 22 minutes." These were almost direct quotations from the scholarly paper.

By the fourth sentence, the reporter informed us: But other experts cautioned that the study did not show that TV watching caused people to die sooner, only that there was an association between watching lots of TV and a shorter lifespan. For the next few sentences, the reporter allowed these experts to tell us why correlation is not causation.

And yet, the reporter, the headline writer and the editor persisted in telling readers "too much TV may take years off your life".

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Such mischief is not limited to Yahoo!  Here's Time magazine with an even more ridiculous headline:

And taking the prize was AOL/HuffingtonPost:

This above headline is frankly embarrassing. According to the study, each hour of TV after age 25 is associated with 22 minutes lower lifespan. Each additional hour of TV is associated with a higher risk of death. But how did this finding morph into (just) one hour of TV could shorten one's life? Turn this around. Would doing just 1 hour of exercise in one's lifetime prolong one's life?

And the ailment has already crossed the Atlantic. Here is the Independent (UK):

If the writer has read the paper, he will note that in the sample, only 1% of the people reported watching 6 hours a day or more. In fact, across all age groups (25 and over), the average number of hours of TV viewing was 1.5-2.5 hours per day. So the statement about 6 hours a day is useless for 99% of the population.

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Here are some other pertinent information from the study ignored by the media:

• Every finding in the study just marginally passed the minimum standard of statistical evidence required for publication in a scholarly journal. For example, the reported 22 minutes decline in lifespan had a margin of error of 21.5 minutes.
• Also, that 22 minutes difference come from an extreme-to-extreme comparison. It's the heaviest 1% of TV watchers versus those who don't watch any TV at all.
• What is a plausible link between TV watching and "all-cause mortality" (death by any reason)"? Is the hypothesis that electromagnetic waves are harmful? that excessive violence is harmful? that high-decibel screaming makes us sick? The researchers did not speculate at all. They did bring up smoking as a comparable risk factor, which I find puzzling since the biochemical link between smoking and death is pretty clear by contrast.

If I have the chance, I'd do a survey of those journalists who published these articles to find out what proportion of them stopped watching TV to gain those extra minutes of life.

 

Comments

[Jonathan]

Is it not possible that sicker people are watching TV cause they are unable to do anything else? The results from this study appear to be coincidence at best. Nice job.

[DavidC]

It seems really common for people who are, at least on some explicit and conscious level, aware that correlation isn't causation to take correlation as "maybe causation", whatever that means.

[Ken]

From the abstract "Compared with persons who watch no TV, those who spend a lifetime average of 6 h/day watching TV can expect to live 4.8 years (95% UI: 11 days to 10.4 years) less. " UI is uncertainty interval which I assume is the same as a confidence interval, so it isn't a very convincing study.

It all seems fairly pointless. There is a link between physical inactivity and obesity, and a link between obesity and lifespan. As its fairly reasonable to expect that TV watching cuts into time for physical activity, then there will be a correlation.

[Antonio R.]

Another case of horrible disease?
http://www.dailymail.co.uk/sciencetech/article-2029957/Social-networking-teenagers-likely-addicted-drink-drugs.html?ito=feeds-newsxml
(news reported by many other media)