EBM today

What does it mean to practice evidence-based medicine today?

Gordon Guyatt: I would say there would be 2 major elements. One is to be aware of the evidence in terms of what is trustworthy and what is not trustworthy and look to sources that provide trustworthy evidence. The second is to be aware that evidence never tells you what to do. It is always evidence in the context of values and preferences. Almost all of our treatments will have negative effects including burden, side effects, cost. We are trading off the benefits and the downsides.

There are some instances—if you come into the hospital with a myocardial infarction, taking an aspirin has overwhelming benefits relative to downsides, but there are many other instances where there is a closer trade-off between the benefits and the downsides, where there is major uncertainty. [In such situations] different patients with different values and preferences are going to make different choices. An evidence-based clinician will, first of all, be aware and have access to trustworthy sources of evidence and trustworthy evidence summaries, and will also be aware that evidence itself never tells you what to do by itself. It is always in the context of the patient’s values and preferences.