Because of the tensions in that last conflict, this debate has become somewhat political.

The benefits of evidence-based medicine, when properly applied, are obvious. We can use test characteristics and results to make better diagnoses. We can use evidence from treatments to help people make better choices once diagnoses are made. We can devise research to give us the information we are lacking to improve lives. And, when we have enough studies available, we can look at them together to make widespread recommendations with more confidence than we’d otherwise be able.

When evidence-based medicine is not properly applied, though, it not only undermines its reasons for existence, but it also can lead to harm. Guidelines — and there are many — are often promoted as “evidence-based” even though they rely on “evidence” unsuited to its application. Sometimes, these guidelines are used by vested interests to advance an agenda or control providers.

Further, too often we treat all evidence as equivalent. I’ve lost track of the number of times I’ve been told that “research” proves I’m wrong. All research is not the same. A hierarchy of quality exists, and we have to be sure not to overreach.

There is a difference between statistical significance and clinical significance. Get a large enough cohort together, and you will achieve the former. That by itself does not ensure that the result achieves clinical significance and should alter clinical practice.

Finally, we have to recognize that even when good studies are done, with clinically significant results, we shouldn’t over-extrapolate the findings. Just because something worked in a particular population doesn’t mean we should do the same things to another group and say that we have evidence for it.

Years ago, Trisha Greenhalgh and colleagues wrote an article in the BMJ citing evidence-based medicine as “a movement in crisis.” It argued that we’ve moved too much from focusing on disease to risk. This point, more than any other, highlights the problem evidence-based medicine seems to have in the public sphere.

Too many articles, studies and announcements are quick to point out that something or other has been proved to be dangerous to our health, without a good explanation of the magnitude of that risk, or what we might reasonably do about it.