Day: June 30, 2009

I get mail–chiroquacktic edition

A long while back, at the original wordpress incarnation of my usual blog, I wrote a piece on the reasons that chiropractic is unscientific nonsense. Because it was popular, I resurrected it. Well, a chiropractor has come to bravely defend his field and left me a comment. A study in the May 2007 issue of the Journal of Manipulative and Physiological Therapeutics...

/ June 30, 2009

Screening Tests – Cumulative Incidence of False Positives

It’s easy to think of medical tests as black and white. If the test is positive, you have the disease; if it’s negative, you don’t. Even good clinicians sometimes fall into that trap. Based on the pre-test probability of the disease, a positive test result only increases the probability by a variable amount. An example: if the probability that a patient has...

/ June 30, 2009