Working with the evidence base

The Irish Society for Rheumatology (ISR) Spring Meeting 2023 featured a distinguished line-up of speakers from national and international clinics, who shared their expertise on a range of topics relevant to rheumatology. The meeting was introduced by Prof Geraldine McCarthy, ISR President, who welcomed the attendees and thanked the speakers for their input, and industry for supporting the conference for rheumatology physicians, which she described as a “special community”. 

The meeting heard from Prof Mike Putman, Director of the Vasculitis Programme at the Medical College of Wisconsin, US, who spoke on the topic, ‘Misconceptions and opportunities: Evidence-based medicine in rheumatology’. Prof Putman described how his talk would be focused on three areas: Defining ‘evidence-based medicine’ and how it is practised today; addressing common misconceptions on evidence-based medicine in rheumatology; and looking at how evidence-based medicine can change how a doctor practises.

“My favourite definition of evidence-based medicine is from Dr David Sackett [Canadian physician, pioneer of evidence-based medicine],” said Prof Putman. “He said it is ‘the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients’. I like this definition for two reasons — the first is that I think it gets to the heart of what I am doing when I am trying to practise evidence-based medicine, and when I am trying to teach that to trainees and to people I work with. 

Importantly, it is really so banal as to be almost obvious — I can’t imagine anyone who would say they are not trying to use the conscientious, explicit and judicious use of the best current evidence,” he continued. “The marker of evidence-based medicine is the randomised, controlled trial,” said Prof Putman. “Your measuring device is the meta-analysis, where you combine them, and the unit of measurement is the odds ratio… We are all trying to do that, but I don’t think we are actually doing it.” 

Prof Putman presented research on alternatives to evidence-based medicine, such as ‘eminence-based medicine’, which is sometimes based on the opinion of a renowned physician. Others include ‘vehemence-based’ medicine, ‘providence-based’ medicine, and ‘nervousness-based’ medicine, “where the marker is how scared you are of litigation, and the measuring device is whether or not you have ordered every conceivable test”.

Prof Putman presented case studies to illustrate how to make the best evidence-based treatment choices and described how some of the misconceptions about evidence-based medicine include that it is “too hard”, and that it is “cookbook medicine”. 

“There are so many rheumatology papers every month now, and nobody could possibly read all of those,” Prof Putman told the attendees. “And that is partly because some of these papers are simply too long… not many of us are PhD statisticians and a lot of the statistics can seem kind of scary — path progression models, marginal structural models, and so on. People are doing these things today that we didn’t learn in medical school or residency or rheumatology Fellowships, so a lot of people feel lost when reading these papers. But the problem with most papers is not that they are too complicated; we just don’t know how to read them.” He suggested that the three principles the reader should apply are: How does this apply to my patient; what is the risk of bias; and how great are the benefits and harms of the therapy. 

On randomised controlled trials, Prof Putman told the attendees: “Here is what I like to teach on the sub-questions under each of those headings: Is the sample of patients generalisable, and does background therapy reflect the standard of care? These are two questions that any astute clinician can answer. Also, could unblinding have occurred, and were outcomes objective? You know what unblinding looks like, and you know objective outcomes look like. Were patients lost or crossed over; was the analysis intention-to-treat, what are the absolute risks in the numbers needed to treat and harm; did the results rule-in or rule-out a clinically meaningful difference? 

“These are all questions that anyone who takes a little time to read a paper can get to the bottom of, especially as a practising rheumatologist.”