Dr. Bradley Johnston
Appearances
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah. And of course, we've collected all the data on lipids and blood pressure and anthropometrics. But also in addition, I think we're the first to do systematic reviews and use them to inform guidelines on essentially quality of life items or elements. Yeah.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Well, yeah, really good question. Well, I would say that when I talked about the three central tenants, you know, if we kind of agree that we should focus on outcomes that matter most to our clients or to the public, and if we agree that we should use the best available evidence, human evidence to drive our clinical or public health decisions, um,
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And if we agree that we should kind of this, like you've talked about the art of medicine or let's say clinical practice, we should engagement with the values and preferences of the client. the philosophy of evidence-based practice. And it is a philosophy. I'm not saying that this is the only way, but I think it's a very good way.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
It's been around for 40 years now, and I think there's a lot of confusion. Um, if we believe these things, if these things make sense, then ideally the client family should understand what does the evidence say, and then they should be, should drive the decision. So we, we've referred to it as value and preference sensitive decision-making.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
It's often referred to as evidence-based decision-making, but Maybe to be a bit more specific, it's value and preference-sensitive decision-making based on the best available evidence.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Good question. It's a little tough to answer. We'd probably have to survey them to find out. But I would say my observation is there's a lot of confusion about what evidence-based practice is and isn't. I would say that, let's take an example.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So we've done a systematic review and what we call a network meta-analysis, which is a way to do comparative effectiveness research on all of the available randomized control trials that look at different dietary programs. And when I say programs, I mean diet plus lifestyle and as well as medication and
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So in people at cardiovascular risk with considerable cardiovascular risk, so let's say they have obesity and their blood lipids are off or they have obesity and they have hypertension, what is the best available dietary program? So we did this systematic review, published it in British Medical Journal in 2023 and
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
We found 40 randomized control trials that look at hard outcomes like all-cause mortality, myocardial infarction, stroke. We found 40 trials of seven different dietary programs. So things like the Mediterranean-style diet, low-fat diets, various versions of low-fat, like low-fat, very low-fat.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
The best available evidence for the question, what is the best dietary program to prevent major hard cardiovascular outcomes and mortality is Mediterranean style diet. So there's actually for the outcome, all cause mortality, there's seven randomized control trials. Most of them are done in Europe, particularly in Spain. And the risk reduction, the absolute risk reduction over five years is 1.8%.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So perhaps said in a more intuitive way, 18 fewer events per 1,000 people followed over five years. And this certainty of evidence, if we bring in the GRADE approach, for that risk reduction is moderate. We concluded that there is moderate certainty evidence. The next best diet was a low-fat diet.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Now, of course, low-fat is kind of code for higher fruits and vegetables, higher whole grains, clean meats, fish, that type of thing. For all-cause mortality over five years, low-fat diets were a 0.9% risk reduction. So not even 1%, 0.9. So nine fewer cases per 1,000. And both estimates were statistically significant.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So if you're working with a family or a patient, you can tell them the best dietary programs are Mediterranean style and low fat. And here's what the absolute risk reductions are. Here's the certainty of the evidence. And by the way, there was moderate certainty evidence for low fat as well. And they can make their own value and preference sensitive decisions.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So that would be evidence-based practice for Perhaps done optimally. And I know as a physician, you have limited time to do this kind of stuff.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Okay. So you're an abnormal physician.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yes, I'm a professor, Texas A&M University.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, it makes sense right away. I think, well, people can probably control their skeletal muscle more than they can control their body fat.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, sure. So thanks for asking. Thanks for having me. My undergraduate degree is in kinesiology, and then I did doctoral training in experimental medicine at the University of Alberta. And then from there, I did postdoctoral training in evidence-based health care at Oxford University or University of Oxford and McMaster University in clinical epidemiology and biostatistics.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, well, so ideally our questions should be informed by our patients or members of the public. And so when I talked about the example of how we come up with the outcomes that are a part of our question, that in our case for the obesity management guidelines was informed by parents and caregivers of those with children and adolescents with obesity.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
I'm not sure if I'm answering your question optimally, but Yeah, the question is really, really important. Clear, clean, structured questions. It's actually a skill in evidence. It's one of the competencies of evidence-based practice.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, or for being evidence-based. Right, good question. So, open network paper from 2018, I forget the first author's name, but my mentor, Dr. Guyatt, and other leads in evidence-based medicine practice were a part of basically a Delphi study where they tried to figure out for the health professions, what are the core competencies that they need to have?
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And they came up with 68 core competencies. So that's a lot. And it's competencies.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, it'll only take you two years. There's competencies in treatment, prevention, prognosis, and diagnosis. But if we narrow the scope and think about nutrition, I think nutrition, like registered dietitians, they usually are working with treatment and prevention.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And one of my graduate students, Ruth Ghosh, has led recently a systematic review of the competencies of nutrition professionals and students, like at least what the literature says. We don't actually know what their competencies are, but we have insights from the literature. And we came up with her paper. We boiled it down to what we think are six core, core competencies.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And they are one, asking a clear, clean question, a structured question. Two, skills in finding the literature to answer that question. So you talked about up to date, but also skills in searching PubMed, which is a free version of Medline for your listeners if you want to search the literature.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
There's other databases like Dynamed that kind of brings the best available evidence together for given clinical questions or public health questions. The third competency is skills in essentially assessing risk of bias and determining the methodological quality of a study, whether it be a randomized trial, a cohort study, or a systematic review of those studies.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Um, fourth competency, and this one is really important and it's often left out is competencies and understanding treatment or exposure effects, right? So we, everybody knows about P values and statistical significance, but what we really need to know to make informed decisions is Is the average effect, is it trivial, small, moderate, or large, or perhaps very large?
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And it was really at McMaster where my understanding and passion for evidence-based practice and health research methodology, I should say human health research methodology, really kind of was inspired, I would say.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And so there we look at the point estimate. We start with looking at the relative effects, relative risk, odds ratio, hazard ratio. But ideally, the data needs to be presented also as an absolute estimate of effect, so a risk difference or an absolute risk reduction or increase, which are much more intuitive for decision makers. So that's the fourth competency.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And number five is the certainty of evidence, right? So you have a risk reduction. So let's go back to the example, if I could, on dietary programs for reducing hard cardiovascular outcomes and mortality. Mediterranean-style dietary program had the best available evidence, a 1.8% risk reduction. Again, the certainty of evidence was moderate, but it could have been possibly high.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
or low, or perhaps very low, if it's informed by the grade approach. So an estimate of effect and a p-value without some indication of how certain we are in that estimate of effect, to me, is kind of meaningless if you really want to make informed decisions.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And then the, which competency am I on? The next competency is essentially values and preferences, right?
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, but like you say, it's an art. So if your patient or the public understand what the absolute risk reduction is or increase, how certain we are in those estimates of effect for outcomes that really matter to your patient or to the public. then the art of working with them around their values and preferences to find out what works for them is really important.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And that depends on their kind of unique clinical situation, maybe their income, all kinds of things, right? If you ask if the best evidence is a Mediterranean-style diet and it's quite expensive to do that or people live in a food desert diet,
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
it's probably very unlikely that they're going to be able to follow a Mediterranean-style diet to reduce their risk of all-cause mortality over the next five years.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
I haven't, but this is true. And my mentor when I was at McMaster, Dr. Gordon Guyatt, is kind of the guy who coined the term evidence-based medicine. And he's a wonderful mentor to this day and a great friend. So I've been very fortunate to work with him.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Oh, seven trials on the Mediterranean-style diet for the outcome of whole-cause mortality.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And in fact, I think there's now eight.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Interesting. Well... It's actually more important than the number of studies is the size of the studies, how many participants were enrolled and followed and completed. If it's an experimental study, it's different. We have lots of very large cohort studies. It doesn't necessarily mean that we have a lot of certainty in those estimates of effect.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
But I would, you know, you look at the number of studies, you look at the sample size, and then ideally there's at least a few studies that have replicated the finding in different geographic regions.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Well, there's a risk in that we can have walkbacks if we got it wrong in terms of the recommendations that we've made. And that's a risk, and you risk the trust of the public, for example, or the trust of your patient or your patient base if it turns out that you're making recommendations either at a clinical level or a public health level.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
where the evidence eventually shows you something quite different, right? So a good example in nutrition that's often used is for years we thought that antioxidants would reduce cardiovascular events, but it was largely based on observational studies. Then they did a large randomized control trial of antioxidants, but this time in kind of supplemental form.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
It doesn't matter. There's vitamin C and also antioxidant combinations. And there's a Cochrane review that basically shows there's no difference in hard patient important outcomes. And in fact, there's a small possibility of risk there. So, we don't generally, I think most people know now that there's not really good evidence for multivitamins and minerals or for antioxidants.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Now, it's not to say that there's not certain antioxidants and that multivitamins, minerals are not important. If you've got nutritional deficiencies. Totally. which is a big issue in lots of areas of the world, they can be extremely important and save lives. But in our affluent society, probably no difference for health outcomes that matter.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, fair enough. But then if you actually did experimental studies of biotin, what do they actually show? I don't know if there are any, but biotin is, we know it's, I think, I guess, rich in skin and nails and hair. I might be getting something wrong here.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And so we make an assumption based on our understanding of physiology, but it doesn't actually mean that if you take biotin, that you're going to not lose your hair, you're going to lose less hair. We'd need to know that from a well-done experimental study, ideally a randomized control trial. I don't know if there's any that have been done, but...
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
There's all kinds of examples where we think we have all kinds of ideas based on what we understand about physiology, but then experimental studies come along and it shows something different.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, good question. I think evidence-based practice is a better term because it's applicable to medicine, nutrition, pharmacology, et cetera, et cetera, surgery. And it's really three central tenets of evidence-based practice. Number one is, well, first you actually have to start with what is your clinical question or your public health question.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
I would say yes, very challenging. But first of all, you have to say what type of nutritional studies. So if you're doing a, if you get funding to do a study on supplementation versus no supplementation or versus placebo, it's basically like doing drug trials. It's not near as complicated. But if you are doing a study, let's say in a clinical trial on dietary programs, well,
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
it's not a supplement that you can use a placebo and the antioxidant supplement looks the very same as the placebo and you can blind the study on multiple levels. If you're doing dietary programs, people know what they're getting. So right away, there's going to be some limitations in terms of the inferences that you can potentially make.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, well, so I would say, Gabrielle, what would I say? Well, so you talked about evidence-informed and, of course, evidence-based. I would say we're all trying to help people. We're all using evidence to inform, I think, our practice if you're a clinician or a public health person or a researcher. Um, but to me, I, I kind of make a distinction.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Evidence informed is using evidence, but it's probably, it may not necessarily necessarily be systematic up-to-date evidence or, um, systematic up-to-date and high quality. So, um, we're all evidence informed, but lots of times people say, oh, it's evidence-based, it's evidence-based.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
I think lots of times it might be better to say, well, that person's evidence-informed, but if you want to be more geeky and nerdy, evidence-based practice or philosophy is these three central tenets, and then understanding the competencies.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And then I think if you're in the space of doing applied human research, for example, it's having a strong understanding of research methodology and doing high-level study methods to try and answer the questions that we have uncertainty about.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah. So I think, well, maybe I'll talk a little bit about GRADE, GRADE approach or GRADE methods. So GRADE is a part of evidence-based practice. It's really the sophisticated part of evidence-based practice in some ways. So GRADE does two things. First, it's a method that we use when we're producing systematic reviews with meta-analysis.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And so, by the way, a lot of people just use the term meta-analysis. And I always say, I don't care about meta-analysis. I want to know if it's first based on all of the evidence. So is it a systematic review with a meta-analysis?
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So your target population, intervention, comparator, outcome. You're a clinician, so you're faced with clinical questions on a regular basis. Once you have clarity on that and what you're trying to resolve clinically or from a public health perspective, the first central tenant is using the best available evidence to answer that question.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
What are those things? Nat wants to know. And you bring together all of the evidence on your given question, and you essentially have a team of people screen the articles independently. They do data extraction, they do risk of bias assessment, and then they assess the certainty of evidence using the GRADE approach. So going back to GRADE, if I could...
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Um, so grade is a method to, um, when you're doing systematic review with meta-analysis, you, um, basically assign a certainty of evidence for each outcome on an outcome by outcome basis. So, uh, and the, it can be high, uh, moderate, low, or very low. So there's four categories that, um, answer your question. Um,
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And there's a whole bunch of questions that go into determining what the certainty of evidence is. And there is some subjectivity to grade. People have criticized grade because some claim that it's subjective. I would say that there's over 40 studies that have been published on the grade methodology. It's been around for 20 years. It's based on a group of
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
of methodological people from around the world. And so there's a ton of merit to GRADE. Is it perfect? No, but one of the goals of GRADE is to be transparent about how did you arrive at moderate certainty evidence?
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Like when you looked at the risk of bias, when you looked at issues of potential imprecision, etc. So making copious, transparent notes within your research reports about how you arrived at the certainty of evidence. And another group, somebody else that wants to use your systematic review, they might say, oh, I don't think the certainty of evidence is moderate.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And it's usually, not always, in the form of systematic reviews, high quality, up-to-date systematic reviews with meta-analysis. or high-quality, up-to-date practice guidelines, whether it's a clinical practice guideline or a public health practice guideline. Second tenant is expertise. Dr. Lyon, you've got lots of clinical expertise. That really matters. It's a part of evidence-based practice.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
I think it's high or I think it's low. That's fine. They can disagree.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And it should create conversation and transparency rather than black box kind of science.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yes. Yeah. So the evidence, the great evidence decision framework is what we use and follow in order to make our recommendations. So it looks at the totality of evidence on benefit, on harm, the certainty of evidence, values and preferences. It has questions on cost, on acceptability and feasibility of potential interventions that you're looking at.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So it's a way to move from the body of evidence, like a systematic review with meta-analysis, to a recommendation for patients or the public.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Why do we care about grade or evidence decision frameworks? Is that...
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, well, I think that's a really good question. So GRADE has been adopted by, I think, now over 120 organizations worldwide. So WHO, CDC, Cochrane, Joanna Briggs Institute in Nutrition, the American Academy of Nutrition and Dietetics uses it to inform its evidence analysis library, which they do systematic reviews and guidelines on.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So it's good to have a common standard across health sciences, right? So whether it's surgery or medication or nutrition, we're comparing apples with apples.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah. And so the main benefit is if you as a clinician are looking at systematic review evidence to inform your practice, you can say, okay, there's moderate certainty, there's low certainty, and that can help inform your practice.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And then the second component of GRADE or GRADE approaches is the methodology, like we've talked about a bit, to move from systematic reviews to recommendations or making strength of recommendations. So exactly as you pointed out, evidence to decision framework. So GRADE is, you can kind of think of it in two different categories. Yeah.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And the third tenant is it's not the evidence that drives the decision clinically. It should be the values and preferences of your client or your patient or your target population. If they're informed, if your patient or client or the population has an understanding and is informed about the best available evidence.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, there's definitely. There's tons out there. Yeah, there's tools available to us to determine the quality of systematic reviews. So the one that's used most is called AMSTAR2. I forget what the acronym stands for, but it's out of the University of Ottawa, Beverly Shea. You Canadians. And there's also something called Robus, which was developed by the Cochrane Collaboration.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So there are two instruments that can be used to determine the methodological quality of systematic reviews. Amstar has 16 questions that you have to go through. And there's also things like JAMA user's guides to the medical literature and what we've produced, the nutrition user's guides to the nutrition literature, essentially.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And we have guidance available to help people make sense of systematic reviews.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Well, I think I know what you're driving at. You definitely need a common structure. Otherwise, people's biases get in the way. There's a whole field of cognitive biases. And even scientists are very good sometimes at having biases that they may be unaware of, right? There's There's something called the sophistication effect.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
It's a cognitive biases where smart people can explain away their answers. Right. So, yes, we need common structures to answer clinical and public health questions and make guideline recommendations. Otherwise, and in a transparent structure. Otherwise, it's hard to have conversations and reach consensus. Right.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Why does it matter to you? Well, I was kind of trained in evidence-based practice and health research methods. And it's a passion because it's a hard question. Why does it matter so much to me? Well, it matters because we're trying to help people. And we want to help people make informed decisions. We want them to understand.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
If they're so inclined, there's lots of people, I'm sure you had lots of patients, they just say, you know, you tell me, doc. But there's lots of patients and families that would love to know why. What is the best available evidence? And can you help me understand it if I take this drug versus I do a behavioral intervention versus surgery, right?
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So I think about the Canadian Pediatric Obesity Management Guidelines. We've done systematic reviews on all of those topics. And The goal is when it's published is people can make more informed decisions about all of the outcomes that we've summarized.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
They can choose the outcomes that matter most to them and get a sense of what the risk reductions are and the certainty of the risk reductions and the potential harms. rather than, for example, the expert or the clinician driving that decision. Always. I don't think that that's necessary.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
It's obviously a great idea if you're in acute care medicine, but it's not a great idea for managing chronic disease.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
That would be ideal. Optimal.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, well, there's, so there's been debate about is grade applicable? Is it optimal for the, in the space of nutrition? And I believe, we believe that it is. And nutrition is complex sometimes, as we've talked about.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
When you're doing grade or using grade, it's very important to be working with nutrition experts to make sure that you understand or the group has an understanding of the nutritional intervention and maybe the biochemistry under it and so forth. So that when we're doing the certainty of evidence on an outcome by outcome basis, that we're not missing something. Right.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So GRADE has a, there's a domain called, I won't go into nitty gritty, but there's a domain called indirectness, which essentially means if there's issues of indirectness. So if you have animal model data and you're trying to make a recommendation for a patient, you have an indirectness issue.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Right. So using RAID, you would probably rate the certainty of evidence down. So you might have a body of randomized control trials, but they're all rodent model studies. But it's the only data that's available for the clinical question you're trying to resolve. Um, randomized trials using grades started high, but, um, can be rated down for different issues, including indirectness.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So you would rate, you would definitely rate down at least, um, one level or probably two or three levels because you only have animal model data. So it would quickly go from high certainty, even though it's based on a systematic review of randomized trials, probably to low or very low because of this indirectness issue.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Well, that's the other thing is evidence-based practice is kind of hard work. You have to, you know, to keep up with the literature when in a kind of banana type atmosphere.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah. So I'm not exactly sure how to answer your question. What's the specific question?
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Or maybe it's low. Maybe there's evidence and it's low and people are willing to embrace the uncertainty that we don't really know. And that's okay. Like, I think sometimes people are fearful of low or very low certainty evidence. Yeah. When I talked about grade to do strength of recommendation, so our recommendations when we follow grade are either strong recommendations or they're conditional.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Mm-hmm. Well, so my mentor, Dr. Guyatt, he's, like I say, one of the prime movers in that space. And his mentor was a guy by the name of Dave Sackett, who founded the McMaster Department of Clinical Epidemiology and Biostatistics. So it's evidence-based medicine and practice has been around, I think, the term was coined in around 1990. Which is so, I mean, it's not that old.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And the strong recommendation can either be for or against an intervention, as well as the conditional recommendation can be for or against. A strong recommendation basically means just do it. There's very compelling evidence, and most patients are members of the public. They value the intervention.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
The tradeoff between benefits and harms is it's much in favor of benefit, and we can make a strong recommendation.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, no. Well, right away I'm thinking I don't know what the evidence is for that. But I know there's been controversy probably at least in things like prostate and breast screening and so forth. Yeah.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Well, so I can use an example from... Managing obesity, whether it's adults or children, I think generally we tend to make a strong recommendation for multi-component behavioral intervention. So if you meet criteria for obesity and especially if you've got your lipids are off and we know it's an important risk factor for early mortality or early chronic disease,
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
We can make a strong recommendation. We'd have to look at a specific situation, but strong recommendation for multi-component interventions. So diet, physical activity, maybe kind of psychological support or group support, behavioral support. That is that that would be perhaps an example of a strong recommendation.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
I don't know what the recommendations are on statins, but I'm sure that there's strong recommendations for certain patient populations in like up to date would probably give guidance on that, I suspect.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah. So generally, using the GRADE approach, we make a strong recommendation if the certainty of evidence is high enough. And all or almost all patients or members of the public value that tradeoff between benefits and harms.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So this is what I was asking. People did the trial with rigor and reproducibility. That was my question. So what's the specific question?
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, there's definitely variation in terms of how well people do studies. And I think it's important to remember that when we're talking about grade and certainty of evidence, this is applicable only for systematic reviews with meta-analysis.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
If you're just looking at a single study, well, we know from the hierarchy of evidence that randomized trials tend to give more reliable answers than observational studies. But we can't assume that because there's one randomized trial that shows a favorable outcome for outcomes that matter to patients, you can't assume that that's high certainty evidence.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, for me, it's kind of old. But like, yeah, relatively speaking, it's, yeah.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
There could be other studies that have been published that you've missed. Um, so, um, I'm talking really from the application of grade is that obviously an evidence synthesis level. Um, and the other thing that I thought might be worth, um, talking about is most recommendations that are made using the grade approach are conditional, meaning we don't have great evidence, right?
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And there's nothing wrong with conditional recommendations. It was great. Previously used the word weak recommendation and people, great, eventually learned that people don't like the idea of a weak recommendation.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, so when GRADE, up until just a few years ago, the language that GRADE was using was mostly strong versus weak recommendation, but they've decided as a group to use conditional rather than weak because a lot of people were uncomfortable with making a weak recommendation for maybe an intervention that they've been using for years. And it puts people in a somewhat uncomfortable position.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
But I think what's important to understand is Okay. Conditional recommendation basically means the evidence isn't great. Values and preferences differ. Like some patients will take it or some members of the public will be interested in following it and others won't. And it should be ideally, they should be informed. It should be shared decision-making. There's nothing wrong with that.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And if we did that more often, maybe in the space of nutrition, maybe there's less room for walkbacks. Like the example of antioxidants, eventually we realized that there's no good evidence for taking antioxidants to reduce cardiovascular risk.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yes. Not that long ago. I forget his first name. Gene Glass. Gene Glass, yeah.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yes. So analyzing multiple studies.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, I think another important component is I think some people that maybe have a perception that if you only have observational studies for a public health question or a clinical question, then automatically it's going to be a weak or conditional recommendation. Automatically, the certainty of evidence is low. That's not necessarily always the case using the GRADE method.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So some people might be familiar with the old school static hierarchy of evidence where at the top were systematic reviews and meta-analysis of RCTs. And after that was systematic reviews of observational studies. And below that was RCT, a single RCT, single cohorts. Grade is a sophisticated approach.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah. So my interest when I did my PhD at the University of Alberta, my summer job was working at the Evidence-Based Practice Center, which was sponsored by AHRQ, which is a U.S. organization. They have evidence-based practice centers around the U.S. and they used to have them and sponsor them in Canada. I don't think they're any longer in Canada. So I became somewhat inspired there.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
It kind of starts to some degree with that hierarchy, but the evidence can move up or down depending on a whole bunch of questions we ask of the body of evidence. There are examples of observational data only that move up from low to possibly even high certainty evidence. So the example that most people would be familiar with is smoking and lung cancer, right?
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
We don't have randomized trials of smoking and the risk of lung cancer, but we have a lot of observational data that And we have observational data that shows large exposure effects and a very clear and reproducible dose response curve. So with that observational data, which has its limitations, we do have high certainty that smoking is a problem when it comes to risk of lung cancer.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, sure. So we created it, a group of us who kind of work together regularly, a lot of people that have kind of come through McMaster University.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Well, I mean, a lot of people, I guess, have websites now. It's a resource where we kind of park materials to help people interpret the literature, like our nutrition users guides that we're starting to publish.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
We talk about some of our guideline work on the website. And yeah, it's just a home to really promote evidence-based practice in the field of nutrition. Because my sense is it needs some uplifting.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
I'm curious. I've never looked at that question, but we probably have mostly observational studies. And it's what fruits and vegetables at what dose?
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Well, if you're doing like dietary programs, it's very hard because people know what they're getting. You can't blind it. People can, they're kind of typically done in free living environments, although of course there are feeding trials. I've done those. You've done feeding trials? Yes. Yeah.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah. And unfortunately, as I understand it, a lot of those metabolic boards are kind of drying up and there's not a lot of funding to keep them going, which is really sad because there's still a lot of work to do in this space. And I'm a huge believer that we need more randomized trials in the space of nutrition because there's a lot of controversy there.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
I got involved with the Cochrane Collaboration, started doing Cochrane systematic reviews of the literature, particularly on probiotics for gastrointestinal infections. And then luckily I arrived at McMaster eventually and kind of learned firsthand from some of the prime movers.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
There's a lot of areas that we really have uncertainty about. And the only way to answer some of these questions, not all, because there's limitations with randomized trials, of course, is to do the trials. And I can talk about examples.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So the systematic review that I mentioned earlier that we published in the British Medical Journal, led by Giorgio Karam, who's currently a medical student at the University of Manitoba.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
No, this is BMJ systematic review network meta-analysis of popular diets for reducing mortality and cardiovascular outcomes.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So I talked about seven randomized trials that measure all-cause mortality. Only one of them, all of them are mostly, most of them are in Europe, I should say. And the biggest ones that people might be familiar with are PREDIMED, almost 7,500 people randomized. So that single trial is probably driving the effect size to a considerable degree.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
There's only one randomized trial of a Mediterranean-style diet in patients that have cardiovascular risk in the United States.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Only one. And it shows basically no important effect when it comes to reducing all cause mortality, like trivial to no effect. So we should be doing, there's a food is medicine research initiative now by the American Heart Association and others that
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
we should be doing Mediterranean-style dietary interventions for these patients and comparing it to the either low-fat type intervention or whatever the typical standard of care is. A second example is you might be familiar with salt substitutes, low-sodium salt substitutes. There's some really compelling randomized control trial data, mostly out of China,
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
that shows important risk reductions in stroke and mortality.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, so normal table salt is like 100% sodium chloride. But you replace some of that sodium chloride with potassium chloride exactly, like 25% of it, based on some of the Chinese studies. And, um, you're, we're showing important risk reductions, absolute risk reductions, um, with, I think, uh, uh, probably a moderate certainty evidence level.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Um, but there's only one randomized trial again, that's been done in the United States or in Canada. And they only measured, um, like surrogate outcomes, like blood pressure. They didn't measure mortality if I'm not mistaken. And it, and the study is quite old. I think it might be 20 years old now or more.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So we need to do the trials here in North America to see if we can reproduce these studies and to help determine the certainty of evidence after we do experimental studies or more experimental studies.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Who knows? I'm a professor, an associate professor there. And I've got grad students, a number of PhD students. And we don't do randomized trials. We do a lot of work in evidence synthesis, systematic reviews, primary studies on values and preferences.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
I think we need a group of trialists that are in the space of nutrition that come together and can work together to ask some of these important questions and do rigorous, high quality, randomized trials. But there needs to be funding. Not necessarily within nutrition. I think you can get funding from different NIH groups.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
You just need people that have that nutrition expertise and clinical trial expertise, methodological expertise to come together as a team and to write those research proposals and try to get them funded.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
I think so. I mean, I don't know systematically, but that's what I kind of hear or see on social media. But I think we need more experimental studies and we need to train people more.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, ideally.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, the scientific mindset. Well, all of us as scientists, we endeavor to have that. And I think we probably all have different definitions. But when I think of that, I think of curiosity, intellectual curiosity. um, about questions about staying open to the data. I think about, um, being agnostic, um, to the data, especially if you're doing guideline work or doing systematic review work.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Good question. I would say when you're in the space of people that are doing research that emphasize or have been trained in evidence-based practice, at least at McMaster, there's a real emphasis on health research methods and doing systematic reviews and getting an understanding of the methodology of randomized trials, cohort studies, case control studies.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Um, it takes it also, I think a bit of bravery, um, to, to be agnostic and to, to be open-minded and stay curious. It's like, We all are human beings and we've got our cognitive biases.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
So I can tell you maybe a story of my own cognitive biases that I probably remember for many years is not that many years ago, we were doing a systematic review meta-analysis on, again, dietary programs, but not for mortality, but for cardiovascular risk factors like blood pressures, cholesterols. um, and weight.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And, um, we found 14 different dietary programs across a hundred and I think 20 some randomized control trials. This is also, um, I think in, it was published in the, in the British medical journal. Um, and low fat diets did quite well. They were in like the top five or something. And this is probably going back, um, five or six years ago. I said to my mentor, Dr. Guy, and I said,
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
I'm kind of surprised about low fat. Um, you know, maybe like, should we call it something else? Or, and he, I, he said to me, the data is the data. And that's, that was the end of the conversation. So it's hard to stay curious, I think. And I now do not take any funding from industry. It's not because I believe it's bad.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
I think you can do very rigorous, important work with industry funding, and usually industry is involved in supporting randomized trials, for example, to some degree paying for the intervention, paying for refrigeration. But because I'm in the space of doing research, evidence-based practice and guidelines, it's best to just avoid any misperceptions.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
I'll be sending you emails.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Definitely. Yes, it's a part of the landscape already. I tell my students that AI can either be your competition or your research assistant. Better to make it your research assistant. So we need to keep up with our developed skills and how to use it. When it comes to evidence synthesis, there are tools now that we can use to screen studies.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
There's still a lot of room for improvement, but it's definitely, I know of colleagues in Australia who do a lot in the space of evidence-based medicine practice and they've been, I forget the name of their kind of group, Robot Reviews, I think, in Australia, if you look up Paul Glazio. They work with AI tools. They've been doing it for over five years to create systematic reviews.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
But one of the main lessons they've learned is you actually have to have a methodologist at the center of the review all the time to make decisions. Um, and if you do, um, um, it's very helpful. And I think they've done reviews, um, in something like two weeks where, um, we're working with AI and working with methodologists to make decisions along that pathway.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Um, so there's, yeah, there's, I don't know a whole lot about the space of AI and systematic reviews, admittedly, but, um, yeah. I do believe that it's an important part of the future and it's already here. And I probably have to work on my AI skills a bit.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And eventually you as a trainee you do more and more systematic reviews of the literature meta-analyses and you start to appreciate health research methods and how studies are done the anatomy of studies and what's great and what's not so great. So and then eventually, I guess I found myself in a situation where I'd done a lot of different systematic reviews on quite disparate topics.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah. And I think hopefully we need humans at the center of science. Once AI is being done only by computers, or sorry, science is being done by computers in certain domains, that's kind of scary. There needs to be a lot of transparency and reproducibility to everything that's done and where you have your data open for investigation if it's created in part or in large by by different AI tools.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Thanks for having me, Dr. Lyon. It's been wonderful.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And then I got into the space of doing some guideline work and realized that.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
methods should be at the center of it and people that have really strong understanding of the methodology of human research should be kind of chairs or co-chairs of guideline committees, at least from the McMaster perspective, which is kind of the foundational school that did a lot of the work, the foundational work in the space of evidence-based practice.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Really important is expertise in, for example, a clinical area, but fundamentally important in guidelines is expertise in health research methods. And being agnostic, ideally, to what the data says, you know, so that's really important, too. We spend a lot of time when we're doing guidelines, making sure that we're managing any potential conflicts of interest or disclosures up front.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
I definitely know the name.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Yeah, well, I think maybe, I don't know exactly what his research questions were that he was working on within this context, but another important component of evidence-based practice is when we're working either from a systematic review level and definitely if you're doing a guideline is we spend time trying to understand and prioritize the outcomes that matter most to the target population and
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
And it's usually not cholesterol, unless the guideline is specific to best interventions to manage cholesterol or hypercholesterolemia. It's usually, if you ask patients or members of the public, it's things like mortality, stroke, myocardial infarction, health-related quality of life. And so we spend a lot of time talking about this.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
The concept is often referred to as patient important outcomes. And so studies, whether it's clinical trials or observational studies, they measure lots of things. And for example, I'm the co-chair of the Canadian Pediatric Obesity Management Guidelines that will be published sometime, hopefully early in 2025.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
We started that process by interviewing parents of children with obesity and as well as experts in the field, but mostly parents.
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
parents of children to find out what outcomes matter most to them as um as a family and to their children or adolescents and then once we understood that we did systematic reviews of the literature and um turns out that they said that the most important outcomes to to them and and based on their observations of their children were things like anxiety depression quality of life
The Dr. Gabrielle Lyon Show
The Truth About Nutrition: How You Can Take a Science-Based Approach | Bradley Johnston PhD
Um, and secondary to that was things like BMI, BMI-Z weight, right? So we kind of, um, we, we still did systematic reviews of BMI, BMI-Z weight and, um, different, um, lipids, but the, the outcomes that we really focused on were quality of life.