Severe pain + 2mg of Morphine = severe pain.

- Rogue Medic

How do you feel about Evidence-Based Medicine? Part I

At Science-Based Medicine there are a couple of discussions of Medscape‘s physician-only discussion of EBM (Evidence-Based Medicine) and SBM (Science-Based Medicine).[1]

There are excerpts from some of the physicians’comments – comments which do not suggest that these fans of anecdote-based treatments have good judgment.

Read both articles.

Worry about how these anecdotalist physicians treat patients. What kind of informed consent can these physicians possibly obtain?

Original cartoon

Both Dr. Harriet Hall and Dr. Mark Crislip are surprised by the ignorance demonstrated in the comments of physicians.

I had naively thought that my profession uniformly embraced EBM. How could they not? The commenters broke my bubble big-time. Some of them summarily reject EBM… although it appears that what they are rejecting is not what I understand EBM to mean.

Note: I have excerpted the following quotations from the website, preserving the errors.

. . . .

I see EBM as a way of “dumbing down” medicine to allow NP’s to try to practice medicine

. . . .

Keep in mind that these are not clueless celebrities, anti-vax mommies, or crank CAMsters. These are mainstream medical doctors. I weep![2]

Making it up as we go along is somehow more intelligent than EBM?

and –

It was the lack of nuance that amazed me. That docs had issues with EBM/SBM should be given. I have issues with SBM, but like democracy, it is superior to all the alternatives. And the inability to differentiate between EBM/SBM and the guidelines upon which they are based flabbered my gaster. I have never been able to come to grips with the concept that people who should know better, don’t appear to. Being perfect myself, I am taken aback when others are not.[3]

Dr. Crislip is not being immodest, only silly, but he does know what he is writing about.

Many of the physicians making comments are so biased that they do not even know what they are criticizing.

Doctors are not the only ones who suggest that their experiences and/or intuitions are better care than care based on understanding and applying evidence to patient care. What should we call this kind of attempt at medicine?

Experience Vague Recollection-Based Medicine?

Intuition Whimsy-Based Medicine?

Anecdotalists (those who base treatment on these anecdotes) may practice various combinations of these.

Intuition can also be described as experiences that we do not consciously remember.

Experience is a vaguely reconstructed memory of what we think was relevant when we were treating a patient who may have had a similar presentation – possibly even due to the same illness/injury.

There are more variables than we can know.

[T]here are known knowns; there are things we know that we know.[4]

These are the things we know because of an abundance of very well done studies.

For example, we know that defibrillation improves survival from cardiac arrest.

There are known unknowns; that is to say there are things that, we now know we don’t know.[4]

These are things that we know we need to learn.

For example, the use of epinephrine in cardiac arrest was never based on evidence of improved survival, but only based on epinephrine’s ability to improve ROSC (Return Of Spontaneous Circulation). Does epinephrine cause more long term harm than long term benefit? We do not know, but recent research shows that we do not have any legitimate excuse for anyone to oppose a well done randomized study of epinephrine in cardiac arrest.

But there are also unknown unknowns – there are things we do not know, we don’t know.[4]

These are the things we do not have good evidence to support using on a patient, unless the patient is part of a well controlled study of that treatment.

These are the anecdotalist treatments.

Nobody knows if these treatments work. If we claim that we know, we are lying, ignorant, or both.

If a treatment works, then why can’t we demonstrate it under controlled circumstances?

If it is not something that can be studied well under controlled circumstances, then how can we claim that we know it works?

Everything changes. Just because something about the patient has changed after we have done something does not mean that we caused the change.

To be continued in Part II.


[1] How do you feel about Evidence-Based Medicine?

[2] “How do you feel about Evidence-Based Medicine?”
Dr. Harriet Hall
May 29, 2012
Science-Based Medicine

[3] Science, Evidence and Guidelines
Dr. Mark Crislip
June 15, 2012
Science-Based Medicine

[4] There are known knowns



  1. Reading Dr. Hall’s blog, a lot of the comments she cited show a legitimate – if over-hyped in the comments – concern about the data used to create a treatment recommendation. EBM is limited, too, by its data. It’s a cliche, but garbage in = garbage out. EBM is only be-all/end-all if the information coming out is carefully considered and well understood. Given the volume of information out there, no one doctor or paramedic or even small ambulance service could consider all the studies completely with confidence. For better or worse they fall back on what they know.

    If doctors has a trusted filter they might more readily accept EBM.

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