SGEM Xtra: Presenting in a Northern Constellation

Date: June 27th, 2020 I had the pleasure of presenting at the Northern Constellation Faculty Development Conference 2020 on May 8th. This was the 9th annual conference put on by the Northern School of Medicine (NOSM). Dr. Sarah McIsaac was kind enough to invite me to present at the Northern Constellation Conference. She is an anesthesiologist/intensivist at Health Sciences North, Assistant Professor and Medical Director of Faculty Development for NOSM. This presentation is available to watch on the SGEM YouTube Channel or listened to on the SGEM podcast. All of the slides can also be downloaded from this link. I was asked to give a presentation about evidence-based medicine (EBM), critical appraisal and relate it back to COVID. Certainly there has been a lot of information coming out on the topic and it can seem like you are drinking from a fire hose at times. The presentation was broken down into three parts: Evidence-Based Medicine (EBM), critical appraisal and the Peltzman Effect (risk compensation): Part I: Evidence-Based Medicine (EBM) It is always good to define terms at the beginning of any discussion. I used the original definition of EBM given by Dr. David Sackett: “The conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients.”  (Sackett et al BMJ 1996) There are three pillars to EBM than can be represented in a Venn diagram. People often make the mistake of thinking that EBM is just about the scientific literature. This is not true. The evidence informs and guides our care but it does not dictate our care. EBM also needs your clinical judgement based on your experience. We also need to engage with patients and ask them about their preferences and values. These three components make up EBM: The literature, our judgement and the patients values.  There is a hierarchy to the evidence and we want to use the best evidence so patients get the best care.  The hierarch is usually described as a pyramid with the lowest form of evidence being expert opinion and the highest level being a systematic review. This is an over simplification of the levels of evidence. A good randomized control trial (RCT) can be more informative than a systematic review (SR) that only includes low quality study (GIGO – garbage in, garbage out). There are arguments against EBM and it does have limitations. One that is often pointed out is that it would be unethical to do an RCT on harm. The 2003 Smith and Pell parachute trial is usually pointed to as an example (BMJ 2003). This could be considered a straw man argument because most medical practices are not parachutes (Hayes et al CMAJ 2018). In addition, a randomized control trial has been done assessing the efficacy of parachutes to prevent gravitationally related morbidity and mortality and was reviewed on SGEM#284. Five alternatives to EBM were discussed (Adapted from Isaacs and Fitzgerald BMJ 1999) :