In 1959, a young doctor named David Sackett stumbled on a clinical trial that would change his life – and most of ours. The study showed that conventional wisdom on bed rest in medicine was wrong. And it helped lead Sackett and others to develop evidence-based medicine, in which doctors today make decisions based on rigorous scientific research.
It was a necessary corrective. The history of medicine is littered with practices once assumed to work but which were later shown by research to be useless or harmful – as I discovered in the five years it took me to research my book, Beyond Belief: How Evidence Shows What Really Works.
Sackett was a precocious young doctor in his final year of medical school at Cook County Hospital in Chicago, when he noticed something odd. Most medical advice was based on received wisdom or the opinion of the most senior doctor in the room (an approach now called eminence-based medicine). This was unsatisfying to Sackett, who realised he lacked the information to determine which treatments worked best for his patients.
Then, one day, a teenager set Sackett on a new path. The adolescent had an enlarged liver as a result of infectious hepatitis, which Sackett later ascribed to hepatitis A. Back then, everyone thought that a patient with hepatitis must be kept resting in bed until the liver returned to normal. It was conventional wisdom, and no one really questioned why.
But Sackett’s patient did question why. He felt energetic after a few days, and he demanded to get up. Soon, a battle was raging between an increasingly sulky adolescent and a stubborn doctor who predicted permanent liver damage if the young man dared to get out of bed.
Seeking more information, Sackett went to the library and started scouring medical journals. Here, he found the remarkable bed rest trial. It had been published in 1955 by Thomas Chalmers, a doctor and pioneer in clinical trials.
In the early 1950s, during the
Korean war, Chalmers was based at a US army hospital in Kyoto, Japan. The US military used Japan as a base for treating soldiers evacuated from the front, and the hospital was dealing with a big outbreak of infectious hepatitis among its patients.
Strictly enforced bed rest meant that soldiers were in hospital for about two months, creating a drain on the army. So Chalmers decided to test whether resting this long was necessary using a randomised controlled trial – an unusual experiment at the time.
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Chalmers identified men with similar hepatitis symptoms and then randomly assigned them to one of two groups. In one group, men were kept to strict bed rest – so strict, in fact, that they were allowed only one trip to the latrine each day and a once-weekly shower. Men in the other group were prescribed “ad lib rest”, which meant that they could do largely what they wanted as long as their boisterousness didn’t break the ward rules.
The results of this trial showed that the men recovered just as quickly when they were active as when they were confined to bed. Chalmers recommended that hepatitis patients should be allowed to get up earlier – presumably a relief for hundreds of restless soldiers. In 1955, Chalmers also wrote up his findings in one of the most detailed clinical trial reports ever published, at 73 pages long.
As Sackett read this epic paper in the Chicago library, he immediately saw that conventional wisdom on hepatitis treatment was wrong. He convinced his supervisors to let the bedbound teenager get up – and sure enough, the patient recovered just fine. But the incident left a bigger mark on Sackett. It showed him that other standard practices in medicine could be wrong too, and that randomised trials had the power to show which ones had a beneficial effect.
In the short term, this meant that Sackett became a self-professed troublemaker. Now, when senior doctors told him to treat patients because of conventional wisdom, he challenged what they said. He became notorious for interrupting senior doctors whenever they were pontificating about what to do.
But the aftershocks were greater than this. A few years later, Sackett joined the newly established medical school at McMaster University in Ontario, Canada. Here, he and his colleagues started teaching student doctors to solve problems using evidence from research – such as randomised trials – rather than just doing what eminent physicians said.
This approach eventually became known as evidence-based medicine, a term first published in the medical literature in 1991.
Within a decade, the principles had been integrated into medical teaching all over the world. By 2014, evidence-based medicine had been called one of modern medicine’s greatest intellectual achievements – ranked alongside sanitation, antibiotics and vaccines.
A lesson we keep forgetting
Today, it seems obvious that doctors should base their decisions on rigorous scientific evidence. It is remarkable – and not widely known outside academia – that evidence-based medicine is such a recent phenomenon, which is one reason I wanted to write my book. By helping spark this change, the bed rest trial has indirectly benefited everyone who has received modern medical treatment.
Of course, evidence-based medicine is imperfect and rightly continues to evolve. Evidence is often complex, flawed and contradictory, and new studies can come along that overturn existing ideas. But it can help people do more of what works and less of what doesn’t. It’s a hard-earned lesson we shouldn’t forget.
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