Every day we get bombarded in the news with health statistics. Coffee causes cancer! Coffee cures cancer! And so on. Many of these are meant to grab headlines (and, these days, webpage clicks) and the articles they accompany are often very poor at telling the reader what they mean. They often have statistics, and health statistics can be complicated. Sad to say, even many physicians are pretty poor and sorting out the hype from the helpful. This article is a very helpful guide to finding your way when you are reading the health news. It’s called “Helping Doctors and Patients Make Sense of Health Statistics,” and it does just that. I’d bookmark it or even print it out for future reference, if you’re more old school. Don’t be put off by the somber looking first page — it’s actually quite readable. There is also this one, from the always readable Scientific American. I like it a lot, too. It tells you how statistical significance doesn’t always mean real life significance.
Here’s one useful tidbit from the first article — the notion of absolute versus relative risk. For example, consider a problem that happens one in a million times. What if a medication changes that to twice in a million? That’s a 100% increase in risk! Horrible! But the new absolute risk is still incredibly tiny. So you need to look at the actual number, not just the percent change.