Guest post by John M. Henshaw
John Haygarth is scarcely remembered today. But the British physician (1740–1827) was highly regarded in his day, when he made important contributions to the prevention of smallpox and to the treatment of patients with fevers. He was also one of the very first physicians to publish a study of what we now call the placebo effect.
Ask any doctor, and he or she will tell you that the placebo effect is real. Sick people sometimes do get better just because they think they are being treated with powerful medicine. One consequence of this is that the placebo effect must be accounted for when measuring the effectiveness of a new treatment. In order, for example, for a new drug for treating high blood pressure to be considered effective, patients treated with it must show significant improvement compared to those treated with placebos in carefully controlled clinical experiments.
In John Haygarth’s day, however, what we now call placebos played a much different role in medicine. In an era when they were virtually powerless to treat a whole host of maladies, doctors often administered “medicines” that they knew had no curative abilities. But that’s not what they told their patients. Thomas Jefferson wrote about a successful physician who claimed to have prescribed “more bread pills, drops of colored water, and powders of hickory ashes, than of all other medicines put together.” Many doctors saw nothing wrong with this practice, and some of their patients who received these bogus treatments actually did get better.
It’s a fine line between that sort of behavior and the kind of medicine practiced by a well-known contemporary of Haygarth’s, the American physician Elisha Perkins (1741–1799). Perkins was what we would today call a quack, and even in his day there were many who identified him as such. Perkins invented, patented, and successfully marketed a set of strangely shaped metal rods, supposedly made from special alloys, called Perkins tractors. Among the many purchasers of these devices was one George Washington. Perkins claimed that the rods, in the hands of a skilled practitioner, could “draw off the noxious electrical fluids that lay at the root of suffering.” He treated a whole host of ailments with his tractors, and had legions of followers. Perkins’ son, Benjamin, introduced Perkins tractors to England, where they were also successful.
And it was there, in 1799, that Haygarth investigated their efficacy by first purchasing an authentic set of Perkins tractors and then using them to create a second set, made of wood, but painted to look like the real thing. Haygarth ran a test in which he compared the effectiveness of the real Perkins tractors to the fake set—the latter being what we might today call the placebo set. Haygarth’s experiment, while crude by today’s standards, allowed him to conclude that both sets of tractors, the authentic ones and the wooden fakes, were relatively successful at relieving the symptoms of his patients, all of whom believed they were being treated with the real thing. He recorded his findings in an 1800 book entitled On the Imagination as a Cause & as a Cure of Disorders of the Body.
But Haygarth, it seems, was ahead of his time. More than a hundred years later, physicians were still evaluating new medicines and treatments not through controlled quantitative clinical trials but instead qualitatively, by consulting panels of experts. It is now well understood that being administered a placebo during a clinical trial is not at all the same as receiving no treatment at all. Today’s controlled clinical trials employ powerful statistical techniques to quantify the effects of modern medicines.
The list of remarkable medical innovations that predates the widespread acceptance of the controlled clinical trial is long indeed. It includes the discovery of penicillin and the advent of insulin therapy, among many others. Why was the quantitative statistical approach to determining the efficacy of medical treatments so slow in catching on? Among the reasons is surely this one: that medicine was then, and it remains today, an intensely personal science. Human beings—doctors—care for other human beings, trying to cure whatever ails them.
Could it be that the cold, quantitative approach short-circuits, or at least appears to, some part of the human aspect of medicine? Doctors have long since come to believe in the power of the quantitative analysis of medical trials to evaluate new treatments, but nonetheless, medicine remains a gutsy human enterprise. And so doctors have to live in both worlds: the quantitative analysis of cold, unfeeling data right alongside the qualitative, personal aspects of caring for human beings in need.
Perhaps that’s one reason why being a really good doctor is so hard.
John M. Henshaw is the department chair and Harry H. Rogers Professor of Mechanical Engineering at the University of Tulsa. He is the author of An Equation for Every Occasion, A Tour of the Senses: How Your Brain Interprets the World, and Does Measurement Measure Up? How Numbers Reveal and Conceal the Truth, published by JHU Press.