We all want to practice evidence-based medicine.  Yet that phrase is so overused that one must always question the true meaning underlying the use of the phrase.

The first assumption that many make is that evidence is a solid structure without nuance.  Yet we can have different experts look at the same evidence and develop different conclusions!  Why else would we have competing guidelines. Consider this quote from Nietzsche: “There are no facts, only interpretations.”

So what is evidence-based medicine? What proof do we need that a diagnostic strategy is the best, or a particular new medication trumps an older medication, or that the benefits outweigh some unknown risks?

Several factors should come into play prior to giving a medical strategy the seal of approval. We need a preponderance of data. We all know that ACE inhibitors decrease mortality for systolic dysfunction. We have enough studies in various groups that support that statement as clearly evidence based.

But too often we take preliminary data and declare an evidence victory. I still am unsure of the true risks and benefits of coumadin versus the newer anticoagulants in a patient with atrial fibrillation. Do we have sufficient data?

Every physician can spend some time thinking about areas where the evidence really is insufficient to make a declaration that this strategy is evidence-based. Yet we hear and read that term all too often.

So each time you hear or read the term, please be skeptical. Ask what the evidence is. Are we really talking about an interpretation of the evidence? Do we have enough evidence to really say anything about the situation?

We physicians must question authority. We must all understand that science is rarely settled, rather science is always evolving. Strategies that we considered evidence-based in 1975 are considered laughable now. The next 25+ years will show that some of our current beliefs are wrong. If we only knew which ones.

Robert Centor is an internal medicine physician who blogs at DB’s Medical Rants.