Evidence Based Medicine

This is a sneak peek into Chapter 2 of Raising Heretics: Teaching Kids to Change the World, due out on August 1st, and available in all the usual places from that date.


When I was a kid, doctors were treated as demigods. Patients did what they were told, and trusted that medical treatment was always based on science and evidence. Despite a range of negative experiences with the medical profession over the last few years, my default response to health professionals is still one of trust, so I am always horrified when I look into the evidence base for particular treatments, or specific drugs, and discover the alarming lack of scientific rigour that underpins a lot of common medical treatments.

It is disturbing in itself that the term “Evidence Based Medicine” was first coined as late as 1991, by an academic by the name of Gordon Guyatt at McMaster University. It was not, initially, a way of practicing medicine. Instead, it was the name of a course designed to encourage medical students to make their practice more scientific.

If evidence based medicine was only just being talked about in the nineties, you have to wonder how medicine was practiced before that. Sadly, a startling amount of medical practice has historically been based on assumptions, untested theories, and arrogance. And much of it still is.

Consider the treatment of hip pain. In 2018, my daughter, Zoe, was diagnosed with acetabular retroversion and dysplasia, meaning her hip sockets were both too shallow, and facing the wrong way. She was sent to a physiotherapist for rehabilitation, to see whether her hip function could be fixed with the right strengthening exercises. We were exceptionally lucky that the physio she was sent to was Josh Heerey, who, at the time, was working on a PhD in hip problems. Being used to physios poking, manipulating, and making grand pronouncements on the basis of “feel”, I was fascinated in that first appointment to see Josh using a dynamometer.

A dynamometer is a device for measuring force, and Josh used it to measure Zoe’s strength in all directions. This meant that not only did Josh know for sure which muscles were weak and needed work, he was able to use the dynamometer on subsequent visits to measure Zoe’s progress. Unfortunately Zoe’s retroversion was severe enough that she needed surgery, but after 6 months of physio work, she was very strong, which made her recovery much easier. It also meant that her post-surgery rehabilitation was both scientific and effective, as Josh continued to measure her strength and prescribe exercises that directly targeted areas of weakness. After major hip surgery, Zoe is now running and jumping, with no sign of ever having had an issue, except for some trophy scars.

Meanwhile I started having hip pain, and went to a local physio. (Josh was quite some distance away, so I thought it would be quicker to see someone close by.) The local physio diagnosed bursitis, used a tens machine, ultrasound, heat treatment and massage, and after weeks of sessions I got precisely no improvement. In fact, if anything, I was getting worse. I asked Zoe’s surgeon whether her condition was hereditary, and he ruefully confirmed that yes, it was likely her malformed hips were a genetic gift from her mother.

The bad news was that I was too old for the surgery that had helped Zoe. Before too long I was seeing Josh, and competing with Zoe to be the most obedient patient and do all of the exercises as prescribed. It was hard work, but within 6 months the surrounding muscles were strong, and I had no more hip pain. (Unfortunately I then had an insane 3 months of travel that trashed the other hip, so the dynamometer and I are currently close friends again.)

Traditionally the need for various radical and invasive hip surgeries has been determined from damage seen in X-Rays and MRIs. This was not based on studies showing a relationship between scans and pain or functional impairment, or indeed on studies of the effectiveness of the surgeries. It was simply a “logical deduction”. A recent study of the relationship between hip pain and imaging results by Josh and his colleagues at LaTrobe University found that there was actually no correlation between pathology seen in imaging and actual impairment of the hip. Imaging of people with no pain and no impairment showed similar levels of damage to imaging of people with pain and impairment, and there was no correlation between imaging results and hip function. It turns out that a lot of hip pain, my own included, can be effectively managed (and indeed banished) using physiotherapy.

And that’s not an isolated finding. Various studies have found that different knee and back surgeries are no more effective than placebo – in other words, if patients think they have had repair surgeries, but in fact have only had the incision and a bunch of experiences to make them think they’ve had surgery, their recovery is just as good as those who have had the actual surgery. Nonetheless, these surgeries continue to be performed, and described to patients as successful cures. Josh’s evidence based approach to treating hip pain is not, unfortunately, the norm.


It’s encouraging to see, based on articles like this in the prestigious medical journal The Lancet, that we are starting to recognise and acknowledge some of the issues with the way we practice science in general, and medicine in particular. Hopefully this section of my book will become increasingly inaccurate. But the first step is to admit the problem. I’ve lost count of the doctors I have seen who have been defensive and arrogant when questioned. These days I use it as a kind of shibboleth. Any doctor who is not interested in discussing evidence and risk with me is not a doctor who is interested in achieving the best outcomes, and not someone I will bother seeing twice. There are more and more doctors who are happy to be questioned, and who welcome informed patients like me. But there are still far too many of the other kind, and we are a long way from a truly evidence based health system.

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