Monday, November 21, 2011

The dim ages

I used to think that science education would make people more rational and scientific. Now, in the fullness of age and experience, I can see that all it has done is to offer new arenas for people to apply the same magical thinking, self-serving illogic, and rhetorical fallacies that used to drive the ancient Greek philosophers to despair over the human race, too.

I wish I had a certified check for $10,000 for every New York Times story I've read in the past year involving medicine and health, food and agriculture, or psychology that quoted someone committing a post hoc ergo propter hoc fallacy.

Stories about "organic" and "sustainable" agriculture, which always reach a crescendo in this pre-Thanksgiving season, seem to particularly attract unrebutted magical utterances of this nature (such as one the other day featuring yet another bearded guru spouting prodigious volumes of pseudo-scientific claptrap about the wonders of neem oil, herbs, and proprietary concoctions of dung to produce "organic" apples that will make you live forever, experience multiple orgasms, eradicate economic injustice, and save the planet. I exaggerate only slightly.)

Years ago I once remarked to a real scientist how surprising it was how unscientific physicians could be. He was not surprised in the least, observing that "doctors aren't scientists." There was a nice reminder of this the other day in the new study showing that 98 percent of men who are diagnosed with prostate cancer by the widely-used PSA test would have lived just as long, and with a considerably better quality of life,  had they never had the diagnosis at all. This is because the overwhelming majority of prostate cancers are slow-growing and the men who have them drop dead of something else first.

The reaction of patient advocacy groups and urologists was I suppose utterly predictable: they simply could not process this evidence. Men who had been diagnosed with prostate cancer and had it treated were convinced that the treatment had "saved their lives." They just could not accept the idea that there was a considerable chance that all they had been through — having multiple physicians stick various pieces of equipment up their asses and plunge needles into their prostates; long courses of radiation treatment or invasive surgery; multiple side effects — had been unnecessary. The urologists for their part went completely nuts, deeply resenting the implication that 98 percent of the surgeries they had performed were a waste.

In fact, it's even dubious that they had saved any lives at all, because the 2 percent of patients with aggressive cancers whose lives were probably saved by having their prostates removed were offset by an almost equivalent number who died during or immediately after surgery. And of the other 96 percent or so who would have lived just as long in blissful ignorance of their slow-growing cancers, a third suffered incontinence or impotence as a result of their unnecessary treatment.

A similar phenomenon was on display in the FDA's decision to withdraw approval of Avastin for breast cancer treatment, based on the simple fact that scientific evidence shows it doesn't work. Again, patients who (a) had been treated with Avastin and (b) were subsequently alive were absolutely convinced that (b) was the direct consequence of (a). Even more depressingly familiar was their insistence that they knew because they were the ones it had happened to, a species of logic that is behind such other dreary human phenomena as superstition, religion, health food stores, magnetic devices to boost your car's gas mileage, and sure-fire systems for picking stocks.