Well, I thought someone else was sure to write about this, but they haven’t.
Were you as alarmed as me to see the headlines telling us that every hour spent watching TV reduces your life expectancy by 22 minutes? It wasn’t the content of the headline that alarmed me, it was the knowledge that if I read further, I would find yet another example of dodgy ‘research’ and shite journalism which would raise my blood pressure to a dangerous degree, but that I would have have to read it anyway. And so it proved.
The Australian researchers had analysed the results of a large population lifestyle study (the Australian Diabetes, Obesity and Lifestyle Study), looking at data collected between 1999-2008. They concluded that watching six hours of TV a day reduces life expectancy by 4.8 years, compared with freaks who don’t watch any TV (I wonder how many of those there were? I don’t know because I could only be arsed to read the abstract).
Now that’s bad enough, given that if you’re watching TV you clearly aren’t taking exercise at the same time, unless you’re tuned in to the porn channel. If you watch six hours a day, you probably aren’t taking any exercise at all, other than trips to the fridge for more beer during the adverts, and that can’t be good for you, can it, regardless of whether you’re looking at the TV or at the empty space in the corner where any right-thinking person would put a set ?
I can’t believe that they isolated TV-watching as an independent variable, unless they had a large control group who watched no TV, but also took no exercise and had a rubbish diet. And even if they did, there’s another aspect of the results that wasn’t reported in The Telegraph (shame on you) or Mail (to be expected). If you look at the confidence limits (or the uncertainty interval as they call it, in line with recent trends), you get some idea of their data quality. That 4.8 hour figure has a 95% uncertainty interval of 11 days to 10.4 years. In other words, the TV effect could be bugger all or a decrement of a decade.
If we read a paper on the effects of a new drug with that degree of uncertainty, NICE would want to wait for a bigger, better study before approving it. Still I suppose that trying to explain confidence limits to a Mail reader would be a pretty thankless exercise.
They then piled uncertainty on uncertainty by producing that meaningless 22 minute figure. They must have known that this would be the number that appeared in the headlines. Of course, what they are saying is that if six hours per day in front of the telly has the effect they claim, then each hour of viewing would be responsible for 22 minutes of life lost for that particular cohort of sad losers. What it doesn’t mean is that if a slim, normotensive paragon of lifestyle virtue like myself sits down for an hour to watch an improving documentary on BBC2, I’ll be scything 22 minutes off my natural span. But that will, of course, be how it is interpreted by most readers.
As Jerry would say, what a load of arse!
