On The New York Times‘ Well blog, Tara Parker-Pope interviewed NYU journalism professor Charles Seife, author of Proofiness: The Dark Arts of Mathematical Deception. While the book’s not exclusively focused on health care, the interview does touch upon numbers and health journalism.
Once you get past all the goofy catchphrases (proofiness! randumbness!), the basic point Siefe makes in the interview, that correlation is not causation, shouldn’t surprise anyone. Nevertheless, I enjoyed his elegant, health-related illustration of the phenomenon:
We are extraordinary pattern-matchers. Anytime there is something that is happening, we try to find a cause. But sometimes in medicine, sometimes things are absolutely random. Our minds don’t accept that. We must find a cause for every effect.
A really good example is the autism issue. Whenever a parent has a child who ends up being autistic, the parent more than likely says, “What caused it? How did it happen? Is there anything I could have done differently?” This is part of the reason why people have been so down on the M.M.R. vaccine, because that seems like a proximate cause. It’s something that usually happened shortly before the autism symptoms appeared. So our minds immediately leap to the fact that the vaccine causes autism, when in fact the evidence is strong that there is no link between the M.M.R. vaccine or any other vaccines and autism.