Tips for learning and teaching evidence-based medicine: introduction to the series

To the Editor:

I am writing to you regarding the new CMAJ series on evidence-based medicine. [Wyer PC, Keitz S, Hatala R, Hayward R, Barratt A, Montori V, et al. Tips for learning and teaching evidence-based medicine: introduction to the series. CMAJ 2004; 171(4):347-8] I applaud your efforts in this regard. As a clinician at at academic institution, and possessor of a Master's Degree in Clinical Epidemiology, I am a supporter of the principles of evidence-based medicine (EBM).

Nevertheless I have found it a challenge to teach EBM primarily because it is a significant challenge to practice EBM. While your series, especially with the "Tips for teachers" component, will go a long way to assisting in the instruction of EBM, unless trainees can use it practically and witness their teachers using it practically, then we will not achieve the goal of having EBM as a core competency of the next generation of physicians.

Article 1 is an example [Barratt A, Wyer PC, Hatala R, McGinn T, Dans AL, Keitz S, et al, for the Evidence-Based Medicine Teaching Tips Working Group. Tips for learners of evidence-based medicine: 1. Relative risk reduction, absolute risk reduction and number needed to treat. CMAJ 2004;171(4):353-8.]. Using Tip 2 on "Balancing benefits and adverse effects in individual patients" requires information on the background risk. This in turn requires efficient access to the types of information cited in the article (references 9 and 10). I think that efficient and effective access to that kind of information in most settings -- either the over-busy hospital ward or the private office -- is a challenge. (I do not say easy access is a problem, because ubiquitous internet connectivity and the plethora of databases make it easy, but not necessarily efficient or effective.)

In some areas of practice there is information to feed into EBM approaches, such as RCT results, background risks, and other epidemiological data. Cardiovascular and cancer subjects seem to predominate in that literature.

Those data do not exist however in other specialty fields, such as pediatrics, making it difficult to practice EBM. In the generalist fields such as family medicine the problem is the huge variety of patients, and the constant shift from simple to complex conditions across age groups. To some extent the cardiologists and oncologists have the data at hand as they are dealing with a relatively fixed group of conditions in a specific age group, and where there has been a tremendous amount of population data collected. This is not the situation necessarily ih other specialties or in a general practice.

I think that the two factors that have hindered adoption of EBM are the challenges of teaching this material, and the challenge of applying it because we often do not have the information required for EBM. Your series will (hopefully) help address the former, but we have not done enough about the latter.

Sincerely,

Hal Siden

H. Siden, MD, MHSc, FRCPC, DABP Clinical Associate Professor Pediatrics, University of British Columbia

Conflict of Interest:

None declared