The World of Evidence, Overdiagnosis, Overtreatment, and Incidentalomas.
Paul Glasziou FRACGP, PhD is Professor of Evidence-Based Medicine at Bond University.
His applied clinical research is recognised throughout the world, answering questions that change the way we make decisions in medicine. He was a part-time General Practitioner for many years.
Paul was Professor and Director of the Centre for Evidence-Based Medicine at Oxford University from 2003-2010. His key interests include identifying and removing the barriers to using high quality research in everyday clinical practice. His research has influenced numerous guidelines and clinical policies and practice (cardiovascular disease management, screening, clinical monitoring, and antibiotics stewardship) and guidelines for reporting research. He co-founded the International Society for Evidence-based Health Care and the RACGP’s Handbook of Non-Drug Interventions. He has authored over 400 peer-reviewed journal articles and 7 books.
“The general idea of evidence-based medicine is almost a no-brainer. It’s that, when we’re making clinical decisions, wouldn’t it be great if you could have the best evidence available to inform your decision…. But, if I had the time again, I probably would have called it Evidence Informed Medicine and there’s lots of different evidence that you need to inform clinical decisions…“
Watch the video, listen to the podcast, read the transcript below
Tell us about your current role and the career trajectory that brought you here…
Paul Glasziou: My current role is as the Director of The Institute for Evidence-Based Healthcare at Bond University and I came here about 15 years ago with an Australia Award, which is like winning the research jackpot. They give you your salary plus they give you some research money to use. I’ve since had to renew the application, as is usual in the research world, so therefore, I’m mostly doing research work but I do a little bit of teaching still, particularly in evidence-based medicine. I haven’t done clinical work as a GP since I left Oxford in 2010, so this was my retirement trajectory.
DMacA: Most of the people watching will be thinking, I’d really like to win that jackpot! What an achievement. That is fantastic. Let me take you back to Oxford. That was a really unusual, remarkable, pivotal period in your career. Tell us about that.
PG: I took over the Centre for Evidence-Based Medicine in Oxford but also a position within the Department of Primary Care with David Mant. That was in 2003 and that was largely to do research work, though I had a greater responsibility there for teaching, particularly the evidence-based medicine in several streams, but also in taking over the work that Dave Sackett had developed in terms of trying to teach the next generation of teachers of evidence-based medicine and researchers in that area. Particularly important, for example, was the annual five day “How to teach Evidence-Based Medicine Workshop” at which we’d have 50 to 100 people. A lot of fun to do although, I must admit, pretty unstructured. People would decide on their own agenda so it was different every year, which made it even more fun for people like me, and just such a diverse group of people from around the world, many of whom I’m still in touch with. That was an absolutely fantastic period, particularly focused on teaching, but also emerging areas for me with new areas in evidence-based practice.
DMacA: It must have been terrific bumping into so many of those experts. Tell me about some of the people you met and the influence they had on your career.
PG: Oxford is just such a wonderful place to be because you’ve got so many of the world leaders in every area of research, generally of science, but particularly health care, as medicine is such a large component of the Oxford Group. And, of course, I ran into Dave Sackett who I visited a couple of times, and Sharon Strauss who was Dave’s protégé while he was there. People within Primary Care like David Mant who built the Department up to one of the strongest departments in Primary Care in the world, and which has continued to grow since he retired. That was fantastic. I got to know Iain Chalmers, whom I’d met a couple of times previously but Iain, as you probably know, after he started the Oxford Database of Perinatal Trials (ODPT) as a sort of pilot, then kicked off the Cochrane Collaboration, in roughly 1994. That was developed by another great character there, and that’s Sir Muir Gray. Muir was responsible for both the funding of the Centre for Evidence-Based Medicine and getting Dave Sackett to come over from Canada, but also recognizing Iain’s idea of trying to have this global collaboration for systematic reviews, and so funded the UK Cochrane Centre initially, which then took up other sources of funding. Iain and I still stay in touch very regularly. He’s now retired but still an absolute live wire.
And then lots of other people around Oxford I could think of: Peter Rothwell, who is a neurologist there, a particularly incisive character who’s made some really major developments, interestingly outside neurology. I think Peter is probably most famous for finding that aspirin is useful to prevent colorectal cancer. Jeffrey Aronson, another fantastic character in clinical pharmacology, and he’s such an incisive thinker, an encyclopaedia of virtually everything, but particularly pharmacology. That’s just to name a few of the characters I met there
DMacA: An absolute galaxy of stars. It must have been such a fertile place for thinking and creativity. I also believe you had some relationship with Stanford?
PG: Not a strong relationship but there are a couple of people there like John Ioannidis and Steve Goodman who are involved in the whole area of meta research. And, there was a paper that Iain Chalmers and I had written in the Lancet in 2009 about the 85% waste in research, avoidable waste. Some of the people from Stanford, John in particular, became involved in a longer series that we did in 2014, breaking it up into more detail and documenting where that recent research waste was occurring and how we might fix it.
“Oxford is just such a wonderful place to be because you’ve got so many of the world leaders in every area of research, generally of science, but particularly health care, as medicine is such a large component of the Oxford Group. And, of course, I ran into Dave Sackett …Sharon Strauss …David Mant … Iain Chalmers…Sir Muir Gray…Peter Rothwell…Jeffrey Aronson… That’s just to name a few of the characters I met there.”
DMacA: Let me bring you back to Evidence-Based Medicine because EBM became almost a religion with evangelical believers. But I think you also accept there are some limitations to Evidence-Based Medicine.
PG: Of course. The general idea of evidence-based medicine is almost a no-brainer. It’s that, when we’re making clinical decisions, wouldn’t it be great if you could have the best evidence available to inform your decision. Gordon Guyatt, who coined the term Evidence-Based Medicine was looking for a way of trying to highlight the difference in the residency training that he was doing at McMaster. But, if I had the time again, I probably would have called it Evidence Informed Medicine and there’s lots of different evidence that you need to inform clinical decisions but certainly that includes randomized trials but it’s not exclusively randomized controlled trials, which is a common error and myth.
DMacA: The other thing about evidence, and you mentioned research waste earlier, can we can we have too much evidence?
PG: You could have too much poor evidence so, if it’s scattered and not pulled together, the scattering of the evidence actually makes it harder to make find the evidence that you need to make decisions. And that was Iain Chalmers idea to try and pull it together in one place and have it synthesized. He’s got a lovely quote from the 1800s which is, I think, from the President of the Royal Society at the time who said that – science consists of these two processes, of the individual pieces of research and discovery and then the synthesis of all of those individual pieces. And the two pieces go hand in hand. – If you didn’t have that second component of synthesis it would be just like having this pile of boulders but not a nice rock fence, so you need both the boulders as the material but then you need the rock fence as well. And that needs a careful selection of the various pieces of evidence pieced together in a thoughtful way.
“ You could have too much poor evidence so, if it’s scattered and not pulled together, the scattering of the evidence actually makes it harder to make find the evidence that you need to make decisions….And that needs a careful selection of the various pieces of evidence pieced together in a thoughtful way.”
DMacA: The next problem we have is how to persuade clinical colleagues that clinical trials are important.
PG: Can I say two things, and this comes from my time in Oxford. One is that I remember being a bit depressed about the long time it was taking for evidence-based medicine to get into practice and I remember Tim Lancaster, who was in that Primary Care Department, saying- ‘Look Paul, the conversation has changed. You can’t now have a clinical discussion about policy without people raising the idea of evidence and that not being controversial.’ And Tim was right. And that’s become truer over time. If you talk to the younger generations in particular, that’s just such a natural part of the conversation now. It’s not “evidence obedience”, but people want to know – what do we already know about this from the research. That was quite a change.
The second part is, and you and I have this sense that we would like to see more research happening in primary care, but it’s not true of all medicine. What really struck me was what Bob Phillips was saying – a paediatrician who became a paediatric oncologist and who used to come down for the Teaching Evidence-Based Medicine Workshop- that in childhood cancer, his principal area, doing trials was just the way you did business. Most children with a cancer were either enrolled in a trial, that’s how they were being treated, they were comparing the current standard with the possible better version, or they were using the protocol that had come from the winner of the previous trial. Now wouldn’t it be amazing if all medicine was like that- if it was just the way you did work. I think it’s increasing and, for the people I know in the ICU networks, that’s become pretty routine. Most people in ICUs are in trials now. So, there are areas of medicine where it’s changing and, I’m very sad to say, that I think general practice/ primary care is still nowhere near that. We’re improving, particularly in the UK, and the Netherlands who have been global leaders. But, the proportion of patients in primary care that are in clinical trials is so small at the moment and we really need to learn to change that. But, I just wanted to point out that’s not true of all of medicine.
“It’s not “evidence obedience”, but people want to know – what do we already know about this from the research. That was quite a change.”
“First do no harm in responding to incidental imaging findings” Ian A Scott, John Slavotinek and Paul P Glasziou Med J Aust
A link to the remarkable YouTube video entitled “A New Epidemic” featuring Ray Moynihan discussing the new disease “Motivational Deficiency Disorder”
DMacA: One of the other areas that you’re interested in, and it’s an evolution from evidence-based medicine, is the idea of overdiagnosis. I think I heard you say that you think everyone should buy their spouse a CT Scan…
PG: Only if they don’t like them!
I just published a paper with a physician from Brisbane – Ian Scott – on incidentalomas, which is the problem if you buy your spouse a CT scan. The average incidence is something between half and two incidentalomas per CT scan that you do, and they’re becoming an increasing problem. Occasionally they’ll save a life but mostly they’ll lead to additional investigations that may harm the person and the incidentaloma is just one part of overdiagnosis. I think there are two major areas; one is discovering those things that we don’t know what to do about, and that’s incidentalomas in routine investigations, even more so in screening, but the other is our expanding definitions of disease. And this was really brought home to me by Ray Moynihan, who was a PhD student here but a journalist prior to that, who’d been working in Too Much Medicine with the BMJ. Ray was really interested in how all the definitions of disease changed. One of the most extraordinary things is that we have rules about how you name dinosaurs -there’s a global committee for that. There isn’t the equivalent for naming diseases. People just invented diseases and Ray showed how easy it was. He developed this idea, and there’s a wonderful video that you can Google, called “Motivational Deficiency Disorder”. It was this spoof on how easy it was to create a disease. In the video, Ray had a severe case but fortunately a neurologist in Newcastle had discovered this new treatment for Motivational Deficiency Disorder. I won’t spoil the rest of it. It’s just a wonderful video to watch, but it is a real problem.
One of the areas that I’m working on at the moment is gestational diabetes. There was a change in definition in about 2014 which roughly doubled the number of women being diagnosed with gestational diabetes, depending if they adopted that new criteria or not. We’ve now had a spate of randomized trials, the first by the Kaiser Permanente Group in the US, and a couple of others, showing that for those extra cases diagnosed, there’s no benefit.
DMacA: You’ve brought us up to date with some of your current research. Tell us a little more about what you’re doing at the moment and what you’re interested.
PG: I’m getting near retirement. I’m going to continue some things and I’ve been thinking how to pick and choose amongst them. Probably the two major ones are that we need to revise the checklist that Jenny Doust, myself, and several other people were involved in for the Guidelines International Network, on how you define a disease. We’ve got this eight item checklist that’s been pretty useful but, having used it now, I can see that we would like it to be a better checklist and to be more widely recognized. Jenny’s been talking to WHO, in particular, about being involved in this, so that we get up to the dinosaur stage at least, of having an international committee that can help decide on what the definitions of disease should be, and how the committee is formed so there’s no conflicts of interest in the people deciding on diseases. That’s number one.
Number two is that I’d been very interested, largely because of the Evidence-Based Medicine Journal that I was editing, that I took over from Dave Sackett, where I would often see non-drug treatments, evidence based non-drug treatments like the Epley Manoeuvre that we all know and love for treating benign positional vertigo, but all sorts of exercise, pulmonary rehabilitation, avoiding peanuts when you’re young to prevent peanut allergy. There are so many good non-drug interventions but they’re not promoted, unlike drugs. We don’t have a good marketing body and nor do we have a non pharmacopeia. We didn’t, but the Australian College of GPs had agreed to the idea of developing one – so we now have a thing called the Handbook of Non-Drug Interventions (https://www.racgp.org.au/clinical-resources/clinical-guidelines/handi )which is evidence-based non-drug interventions. Like the FDA, you need at least two controlled trials, or preferably a systematic review, showing evidence of benefit. So, I would like to see that further developed and internationalized so that every doctor around the world, particularly in primary care, had access to a non-pharmacopeia that sat beside their pharmacopeia would be my dream, and that they pulled it down just as often for using effective non-drug treatments. They are the two big things that I want to continue with.
The Surfing Professors. Paul Glasziou and Chris del Mar in action.
“One of the most extraordinary things is that we have rules about how you name dinosaurs -there’s a global committee for that. There isn’t the equivalent for naming diseases. People just invented diseases …”
DMacA: Listening to you talking about evidence-based medicine, and realizing the enormous influence you’ve had on the academic progress in primary care, people could be forgiven for thinking that you’re a deadly serious academic. But, in fact, I know you’re known as the ‘Surfing Professor’. So, tell me a little bit about the things outside your academic life, your surfing and, of course, about our dear friend Chris Del Mar.
PG: Chris, as you probably know, had a surfing accident unfortunately, about four years ago, and was not surfing after that, and he passed away just over a year ago now. That was very sad to see because Chris and I used to go surfing regularly. So, I’ll tell you an interesting story… because we lived in the same street we used to go in the same car together early in the morning. We’d put our surfboards up on the top and go down to a place called Currumbin Alley and surf together. And because we were two blokes that always arrived together early in the morning, a lot of people thought we were a gay couple. I didn’t discover this for quite some time until one of my friends just asked me … “how close are you and Chris?” and we were very close, but not in that way. So, I miss him a great deal. He did great things for primary care. I think he really raised the profile of primary care in Australia. He was so passionate about antimicrobial stewardship. And, he was just an all round good bloke as well.
DMacA: Paul, thank you very much for chatting to us and thank you very much for your immense contribution to our profession. It’s always wonderful to talk to you.
