Monday, June 20, 2005
The Grauniad gets it right on risk!
Long time, no blog. But today, I've been stirred into action by an excellent piece by Ben Oldacre in the Guardian, a paper I normally pick out for criticism rather than praise. But, credit where credit is due: despite the politically correct, greenish, anti-corporate, anti-science editorial stance, it does also publish some well written and thoughtful articles.
The piece today (Risky business), essentially covers the misuse of statistics by people who don't understand them, thus contributing to needless alarm. The thrust of his argument is that we should be using natural frequencies (ie, how often something actually happens) rather than statistical percentage increases in risk. For example:
"Let's say the risk of having a heart attack in your 50s is 50% higher if you have high cholesterol: that sounds pretty bad. Let's say the extra risk of having a heart attack if you have high cholesterol is only 2%. That sounds OK to me. But they're both talking about the same (hypothetical) figures. Out of a hundred men in their 50s with normal cholesterol, four will be expected to have a heart attack; whereas out of 100 men with high cholesterol, six will be expected to have a heart attack. That's two extra heart attacks. Those are natural frequencies. Easy."
Sounds good to me. He also concludes (quite rightly, I think) that reporters don't go out of their way to scare people (although there are exceptions, I'm sure); they just don't know what they're talking about. To me, that's a lot more worrying and highlights a need for greater scientific literacy in the media as well as in society generally. To quote Oldacre again:
"I could be a lot more forgiving if I believed that a nefarious, knowing, numerate media was choosing to report the higher, scarier percentage figures, to mislead and titillate an innumerate public. Actually, I think that they just don't understand what they are reporting."
Hear, hear.
The piece today (Risky business), essentially covers the misuse of statistics by people who don't understand them, thus contributing to needless alarm. The thrust of his argument is that we should be using natural frequencies (ie, how often something actually happens) rather than statistical percentage increases in risk. For example:
"Let's say the risk of having a heart attack in your 50s is 50% higher if you have high cholesterol: that sounds pretty bad. Let's say the extra risk of having a heart attack if you have high cholesterol is only 2%. That sounds OK to me. But they're both talking about the same (hypothetical) figures. Out of a hundred men in their 50s with normal cholesterol, four will be expected to have a heart attack; whereas out of 100 men with high cholesterol, six will be expected to have a heart attack. That's two extra heart attacks. Those are natural frequencies. Easy."
Sounds good to me. He also concludes (quite rightly, I think) that reporters don't go out of their way to scare people (although there are exceptions, I'm sure); they just don't know what they're talking about. To me, that's a lot more worrying and highlights a need for greater scientific literacy in the media as well as in society generally. To quote Oldacre again:
"I could be a lot more forgiving if I believed that a nefarious, knowing, numerate media was choosing to report the higher, scarier percentage figures, to mislead and titillate an innumerate public. Actually, I think that they just don't understand what they are reporting."
Hear, hear.
