Okay, folks. Here's a great example of citing statistics and playing with the numbers in order to completely mislead your audience:
Albert Thomas (an MD in New York City and member of Planned Parenthood's Advisory Board), in a post on the benefits of the birth control pill, says:
One estimate says that for every 100,000 women who carry a full-term pregnancy, 10 will die from the pregnancy, whereas two deaths might be attributable to the Pill. Put another way, Pill use decreases a sexually active fertile woman's chance of death fivefold compared to pregnancy.
Sounds like the pill will actually save women's lives. Notice how he phrases it: "pill use decreases a...woman's chance of death fivefold." Then he adds the qualification "compared to pregnancy" in order to make the statement more true. But many will miss the qualification and the phrase "Decreases the chance of death" will remain in their minds. That's the sort of poor sentence construction that we try to avoid at STR (see "Clear" in STR's Ambassador's Creed).
If you look at the numbers themselves, though, the Thomas admission that the Pill results in 2 deaths per 100,000 women is startling. Really? Just taking the pill can actually kill someone? Pregnancy and birth are complex and test a woman's body to its limits, and with good reason - she's helping a new human being come into the environment where he can grow and flourish. So we expect pregnancy and birth to carry with them some risk of death. But the Pill? You have 1/5 the risk of death of carrying a pregnancy to term just for taking the pill? That's more than I expected. And what do you have to show for it? Nothing. Oh, I forgot - that's the point.
What's even more troubling about Dr. Thomas's claim is that it is misleading in another way. He doesn't give sources for his claim, but I'd be willing to bet that he didn't include long-term risks of death caused by using the pill, including breast cancer. This is why we have to be careful looking at statistics, especially with death risk claims like these. Substances like birth control pills and activities like abortion can have long term health consequences, since they are so disruptive to the normal functioning of the woman's body. Unless he's adjusted his numbers for this potential risk of pill use, he's misleading his readers.
The lesson? Don't be impressed by statistics unless the conclusions drawn from them are true.
For a careful explanation of the real risks of Pill use, see Chris Kahlenborn's excellent resource, Breast Cancer:Its Link to Abortion and the Birth Control Pill , available for purchase here and reproduced online in its entirety for free here.
Kahlenborn discusses the evidence in the medical literature dealing with breast cancer risks, and he does it in language anyone can understand. (By the way, examining this topic would make a great high school or college biology project.)