SGEM Xtra: How to Think, Not What to Think

Date: October 21st, 2020 This is an SGEM Xtra episode. I had the honour of presenting at the Department of Family Medicine's Grand Rounds at the Schulich School of Medicine and Dentistry. The title of the talk was: How to think, not what to think. The presentation is available to watch on YouTube, listen to on iTunes and all the slides can be downloaded from this LINK. Five Objectives: Discuss what is science Talk about who has the burden of proof Discuss Evidence-based medicine (EBM), limitations and alternatives Provide a five step approach to critical appraisal Briefly talk about COVID19 and the importance of EBM What is Science? It is the most reliable method for exploring the natural world. There are a number of qualities of science: Iterative, falsifiable, self-correcting and proportional. What science isn’t is “certain”. We can have confidence around a point estimate of an observed effect size and our confidence should be in part proportional to the strength of the evidence. Science also does not make “truth” claims. Scientists do make mistakes, are flawed and susceptible to cognitive biases. Physicians took on the image of a scientist by co-opting the white coat. Traditionally, scientists wore beige and physicians wore black to signify the somber nature of their work (like the clergy). Then came along the germ theory of disease and other scientific knowledge. It was the Flexner Report in 1910 that fundamentally changed medical education and improved standards. You could get a medical degree in only one year before the Flexner Report. The white coat was now a symbol of scientific rigour separating physicians from “snake oil salesman”.  Many medical schools still have white coat ceremonies. However, only 1 in 8 physicians still report wearing a white lab coat today (Globe and Mail). Science is Usually Iterative: Sometimes science takes giants leaps forward, but usually it takes baby steps. You probably have heard the phrase "standing on the shoulders of giants"? In Greek mythology, the blind giant Orion carried his servant Cedalion on his shoulders to act as the giant's eyes. The more familiar expression is attributed to Sir Isaac Newton, "If I have seen further it is by standing on the shoulders of Giants.” It has been suggested that Newton may have been throwing shade at Robert Hooke. Hooke was the first head of the Royal Society in England. Hooke was described as being a small man and not very attractive. The rivalry between Newton and Hooke is well documented. The comments about seeing farther because of being on the shoulders of giants was thought to be a dig at Hooke's short stature. However, this seems to be gossip and has not been proven. Science is Falsifiable:  If it is not falsifiable it is outside the realm/dominion of science. This philosophy of science was put forth by Karl Popper in 1934. A great example of falsifiability was the claim that all swans are white. All it takes is one black swan to falsify the claim.  Science and Proportionality: The evidence required to accept a claim should be in part proportional to the claim itself. The classic example was given by the famous scientist Carl Sagan (astronomer, astrophysicist and science communicator). Did the TV series Cosmos and wrote a number of popular science books (The Dragons of Eden). Sagan made the claim that there was a “fire-breathing dragon that lives in his garage”. How much evidence would it take for you to accept the claim about the dragon? His word, pictures, videos, bones, other biological evidence, how about knowing any other dragons or dragons that breathe fire? Compare that to if I said we just got a new puppy and it’s in the garage. You would probably take my word for it. There is nothing extraordinary about the claim. Most of you should be familiar and have had experience with a puppy at some point in your life.