[lauradhamilton]

Is there really an over-utilization of blood tests? MRIs, yes, but I'm not sure that right now we're really doing too many blood tests.

Regarding your point on Bayes Theorem, that's valid in some ways and invalid in some ways. Suppose someone gets a vitamin D test back at 8 ng/mL. There's not really a chance of a false positive. He's deficient and needs supplementation. Making the test cheaper, faster, and more accessible can really only improve the health of the population. It will likely also drive down the cost of healthcare overall, because vitamin D deficiency has all sorts of unpleasant effects.

Furthermore, the literature suggests that the vast majority of doctors do not understand Bayes Theorem. Source: http://yudkowsky.net/rational/bayes

[enziobodoni]

You are demonstrably wrong about the vitamin d. What if it was a specimen swap, and the lab screwed up and tested someone else's blood instead of yours? This happens.

[DocSavage]

The cheaper and faster the tests, the easier it is to reorder a confirmation (or two or three).