The man behind “Evidence Based Medicine”…and so much more
A world leader in clinical epidemiology who changed the way we read and interpret the medical literature. But, who began on a completely different career path…
Gordon Guyatt is a McMaster University Distinguished Professor. His work, focused on Evidence-based Medicine, has resulted in over 1,500 peer-reviewed publications cited over 205,000 times that have made him one of the world’s most cited researchers. He has played a key role in the development and evolution of the GRADE approach to systematic reviews and guidelines
“There are always challenges and we’re still innovating, Clinical epidemiology and evidence based medicine are very closely related. Clinical epidemiology is the science behind evidence based medicine and we’re always doing methodological innovations in clinical epidemiology, informing evidence based medicine practice.”
Watch the video, listen to the podcast, read the transcript below
“… I find myself in the best place in the world, surrounded by these incredibly brilliant people who were totally into mentoring and totally into working together. And it was also the most collegial department in the world. And, still that tradition continues.
I love it. It’s great. It’s exciting. To my surprise, I’m good at it. And I’m in the best department in the world, in this incredibly supportive environment. It was all good luck”
Gordon…just one image from a lifetime of inspirational workshops
Lets begin with a slightly unusual question. Musicians often get tired of performing their old hits. Does evidence based medicine still excite you?
Gordon Guyatt: Yes, very much so. There are always challenges and we’re still innovating, Clinical epidemiology and evidence based medicine are very closely related. Clinical epidemiology is the science behind evidence based medicine and we’re always doing methodological innovations in clinical epidemiology, informing evidence based medicine practice.
DMacA: Evidence based medicine as a concept has changed and evolved. Where do you think it’s going at the moment? What are the different types of evidence that you now see integrated?
GG: There was a recent article looking at the tensions between public health decision making and evidence based medicine. And that was brought very dramatically to light with the COVID epidemic and the challenges that the public health folks faced.
You say, evidence based medicine has evolved and it certainly has. And one of the huge evolutions is that at the beginning we really didn’t quite get it about the importance of values and preferences in decision making. And now we get it. So now, within evidence based medicine, we acknowledge when the evidence is high quality and when the evidence is low quality. And some people who don’t understand EBM, think that it’s just about when evidence is high quality but it’s just as much about evidence when it is low quality
We emphasize that values and preferences are important, but they become even more critically important when you’re talking about low quality evidence. And so our critique of public health was that they did not acknowledge the low quality evidence in which they were making their decisions, or at least nowhere near as visibly as they should. And then they did not acknowledge the values and preferences underlying their decisions. So, in this article recently published, I was quoted in response to something that public health leader had said. He said that public health implicitly acknowledges the limitations in the evidence. And he said, it’s instinct. A lot of it is instinct. And I said that was baloney, complete baloney, because the right way to approach this is to acknowledge the low quality evidence and then say, here are the values and preferences underlying our recommendations.
One of the things that they got utterly wrong, as far as I understand, is that they advised closure of schools. They put a low value on the detrimental consequences to learning, in particular for disadvantaged children, and a very high value on preventing any Covid case. Having acknowledged that, some people might have said, ‘I’m not sure those are the right values and preferences’. So, although we have been writing now over 20 years highlighting how crucial values and preferences are to evidence based decision making, there are still people who seem to remember what it was like in 1990 when we got started instead of what it’s been like from the year 2000 onwards, where values and preferences have been central. The public health officials don’t get it, at least that’s what this article seemed to reflect. Anyway, it’s still perhaps not the perception that many people have, but the areas that we’re pushing are shared decision making and explicitness of values and preferences.
“one of the other big evolutions in EBM has been the recognition that it is not realistic for most practitioners, both because of lack of time and lack of the fairly advanced training that’s necessary to assess the literature for themselves. So, what they need is, to some extent, systematic summaries, but even more so, guidelines that include systematic knowledge. “
Images from the Canadian Medical Hall of Fame.The Canadian Medical Hall of Fame celebrates Canadian heroes whose work advances health in Canada and the world, fostering future generations of health professionals through the delivery of local and national youth education programs and awards. This enduring tribute to our country’s rich medical history is showcased here on our digital Hall of Fame and in an Exhibit Hall in London, Ontario.
Teaching GRADE to intensive care physicians in Kolkata, March 2, 2024.
DMacA: I was very interested that you talked in particular about public health. Where do you see evidence based medicine fitting in to primary care and family medicine?
GG: Gosh, I’m not a primary care doctor, I work as a hospital based general internist and still seeing patients. So, maybe I’m not the best person to talk about it, but I presume primary care practitioners would still like to practise consistent with the best evidence. And one of the other big evolutions in EBM has been the recognition that it is not realistic for most practitioners, both because of lack of time and lack of the fairly advanced training that’s necessary to assess the literature for themselves. So, what they need is, to some extent, systematic summaries, but even more so, guidelines that include systematic knowledge. And ideally what they are able to do is to understand evidence summaries.
A good guideline will say- here are our recommendation, here is a succinct summary of the evidence that goes with it, and here are the underlying values and preferences. And the family practitioner identifies one or more guidelines that she or he thinks are trustworthy in general, is able to understand the evidence summary well enough to communicate it with the patient, knows to look at the values and preferences underlying it, and sees the extent that it fits with their patients values and preferences as a group or individuals. That’s where evidence based medicine will fit in.
And, in terms of another frontier, shared decision making is tough, shared decision making is challenging and we’ve advanced, I think, in providing aids for shared decision making but we have a long way to go. And we continue to work on that.
DMacA: You talked about evidence, summaries and synthesis. So we really ought to ask you briefly to talk about GRADE.
GG: When we started, we thought we were going to train every doctor to be able to critically appraise the literature, read the methods and results. Well, after seven years running a residency program, I realized that that’s not possible.
So how then are we going to facilitate evidence based practice when it isn’t the individual clinicians doing critical appraisal? And it became evident that what we needed to do was to create high quality trustworthy guidelines that do what I just said: Present evidence summaries, so that they are digestible, so that people can understand and communicate the evidence to the patient, and make the values and preferences explicit.
As that vision gelled in our minds, we said, okay, well what this requires is a science of guidelines. Initially people were doing low quality or not very good quality trials or studies. And then we brought in a science of randomized trials and then, how to do randomized trials really well and, when you need to do observational studies, how to do them really well.
At that time, people were doing these literature summaries that were, basically, experts writing whatever they felt like, in whatever way. We said that we needed a science of systematic reviews. So we came up with a science of systematic reviews, which is now very widely accepted. And then we said, wait a minute, the guidelines are still a mess. We’ve got a term to describe the mess that the guidelines were in, which is called GOBSAT, which stands for ‘good old boys sitting around the table’. So, we decided, we need a science for guidelines.
GRADE is a big part of our science for guidelines and it does two things. First, it says, here is how you decide on the quality, or certainty, or trustworthiness, or synonyms for confidence in the evidence. Here’s how you can differentiate between more and less trustworthy evidence, and have a very well structured approach to doing that.
And then, we moved to what we call evidence to decision frameworks, which is to say, here’s what you should consider and how you move from evidence to decisions. So GRADE provides a structure for summarizing the evidence, deciding its quality and we are going to leave very nice, succinct presentations of the evidence, and then a structure for moving from evidence to decisions, which we think every trustworthy guideline should adopt.
“When we started, we thought we were going to train every doctor to be able to critically appraise the literature, read the methods and results. … And it became evident that what we needed to do was to create high quality trustworthy guidelines … Present evidence summaries, so that they are digestible, so that people can understand and communicate the evidence to the patient, and make the values and preferences explicit.”
Winner of the prestigious International award, the Einstein Foundation Award for Promoting Quality in Research
DMacA: So we’ve talked now about the science of decision making, and the evidence base behind medicine, but I’m interested in the fact that you nearly didn’t do medicine at all.
GG: Well, that is true. I am an unusual doctor who never did a biology course throughout high school. I was generally not terribly interested in science. When I went to university, I did English and Psychology. And partway through university, somehow a career in English or Psychology was less appealing than I thought it was going to be. I thought of medicine but then, of course, I had a problem in that I wasn’t eligible for any medical school except one. And, ironically, that medical school was an innovative medical school that happened to have been set up in my hometown of Hamilton, Ontario; McMaster University, which let people in without a science background. And that got me into medical school.
DMacA: So you did medicine, and empirically, one would think you’re going to go towards humanities and narrative medicine, but somebody shone a light on the science. How did that happen?
GG: To start with the McMaster curriculum had, essentially, no basic science section. It had Physiology, which I liked from the beginning, but the Krebs cycle, no thank you. I was in the seventh graduating class from McMaster, and other places would say, these people don’t really learn medicine. When I went to the University of Toronto, a very conservative traditional school, and rubbed shoulders with the new graduates, I found that they didn’t know any more basic science than I did. And that wasn’t because I knew anything, it was because they didn’t. They had forgotten everything. So that part of basic science, which they’re still feeding them in Toronto, is wasting their students’ time. But, clinical epidemiology is a different type of science and a science that, for some reason immediately appealed to me when I was exposed to it.
How to find out, how to really find out what we know, and how we can really distinguish between things we know and things we don’t know was, somehow, tremendously appealing to me right from the beginning.
“I was generally not terribly interested in science. When I went to university, I did English and Psychology. And partway through university, somehow a career in English or Psychology was less appealing than I thought it was going to be……
Above is an image article outlining a brief history of the Medical Reform Group. Read the full story in Connections.
DMacA: Let’s change tack completely now, because your public and academic persona, wouldn’t suggest to people that you have other, very different interests in life. You’ve talked at one stage about identifying with the disadvantaged. Tell me about that aspect of your philosophy.
GG: Just in terms of background, my mother was a Czech Jew concentration camp victim, and I think that definitely influenced my whole perspective on life. But as a resident in training, I helped found a group which we called the Medical Reform group, which was about making high quality health care available to all Canadians without financial barriers. And a major aspect of my career has been working with this Medical Reform group, and subsequently there’s a Canadian Doctors for Medicare group now working for the strongest possible public health care system, and working against the introduction of financial barriers to optimal care.
DMacA: You also have an interest in politics and, indeed, put your own name forward.
GG: Because of my public profile in advocating for universal health care, and the Canadian political spectrum includes a Social Democrat party, the folks from that party came to meet with me and asked, would you run for us? And I said, yes. And, as it turns out, I ended up doing it four times between 2000 and 2008. It was a very interesting experience and I enjoyed it but four times was sufficient. I was fortunately in an electoral area that I could not win, so that meant that I had no risk of having to change my work. And the Canadian system, in contrast to the United States where the election campaign can go on for years, when the government drops the writ, there’s an election 35 days later. So everything’s crammed in 35 days. This allowed me to put aside most of what else I was doing for 35 days for the election. And then it was over. It was good experience and I saw it as another opportunity. I’m an educator. And with respect to the political stuff also, I’ve saw myself as an educator and this gave me an education in running in these election campaigns. It gave me an educational platform.
DMacA: You put yourself forward and you’ve done your bit to try change the world. In that context, what role do you think that medicine has in social justice?
GG: It goes back to Virchow who said that medicine is politics writ large. Frankly, I don’t know what he meant, but if we moved those in the lowest income group, and there are five socioeconomic groups, if we moved people in the lower income into the high income group, it would have a bigger health impact than curing cancer. So, clearly, if one really understands the real roots of ill health, they are to a very large extent socioeconomic.
And so an enlightened profession would be advocating for a policy that minimized income gradation. It seems clear that would have a gigantic impact on the health of the population. Not that organized medicine is ever going to do that, but at least there are elements within organized medicine, where I place myself, that are pushing in that direction.
“How to find out, how to really find out what we know, and how we can really distinguish between things we know and things we don’t know was, somehow, tremendously appealing to me right from the beginning.”
DMacA: We started with a slightly unusual question, and I’m going to finish with another slightly unusual question. I’ve heard you say that you are a fan of Malcolm Gladwell’s book ‘Outliers’. Are you an outlier?
GG: Yes, absolutely. The essential thing of outliers is that it’s all good luck. That is the essential thing about it.When I finished my medical training, the last thing I wanted to do was to be a clinical investigator. I wanted to take care of patients, I wanted to teach. But then my boss said, ‘No, you should really try this. You’ll get bored in ten years, try this stuff’. And I was an obedient young guy and I said, okay, I’ll try it. So, I enrolled in this master’s program and I started to like it. And then I found myself in the best clinical epidemiology department in the world. In fact, at that stage it was one of the only. And, here I am, having been nudged in that direction, I find myself in the best place in the world, surrounded by these incredibly brilliant people who were totally into mentoring and totally into working together. And it was also the most collegial department in the world. And, still that tradition continues.
I missed out part of the story…I’m was going to do this master’s program and people somehow saw that I had potential. So, they sent me to a meeting with the Chair and the Chair asked me how much of my time I wanted to spend in clinical research. And the answer at the time was zero, but I knew that would be totally impolite. So I thought 25% sounded right. He looked at me and said, if you say that in your interview for the program, they won’t let you in. So when I had the interview for the program, the true answer was still zero, but now I said 50%. So they let me in and then the rest of the story is as I described.
I love it. It’s great. It’s exciting. To my surprise, I’m good at it. And I’m in the best department in the world, in this incredibly supportive environment. It was all good luck!
DMacA: It’s just been fun chatting to you. Thank you for sharing your life and most of all your continuing excitement with the whole concept of evidence based medicine and, maybe, changing the world a little bit.
GG: Thank you very much indeed. Well, you’ve picked it up. I am still excited. Thank you very much. It’s been a pleasure
