Professor David Jones of Harvard Medical School on evidence-based medicine, coronary artery disease, and unanticipated side effects
Why would doctors sometimes prescribe wrong treatment? What are the dangers of being on a heart-lung machine? Professor of the Culture of Medicine at Harvard Medical School David Jones speaks on the reasons and consequences of inappropriate treatment.
You can look at many, many different diseases in many parts of this country, in many parts of this world, and it’s a sad truth that there are many people who are getting medical treatment that doesn’t provide the value that they think they’re getting from it. This is an issue for a number of different reasons. On the one hand, it’s just an expensive waste of money. If you are providing medical treatment that’s providing no benefits for patients — that’s just money that’s been wasted. And it’s also dangerous to patients — many medical interventions have side effects of various sorts. And so if you’re giving people treatment they don’t need, you’re exposing them to a series of unwanted, dangerous and unnecessary side effects.
There’s also been a major investment in surgeries and other procedures – things like coronary artery bypass surgery or coronary angioplasty where cardiologists insert a catheter with a balloon to stretch open the plaque and then leave a stent behind to treat the effects of coronary artery disease. The question is whether or not any of these treatments actually work in a way that doctors want them to work. So when researchers have done focus groups of patients who have had angioplasty and asked them how much benefit you think you got from this procedure, 80% of the patients said they expected that their life expectancy would be increased 10 years by this procedure. And that would be great if it were true, but the evidence based-medicine suggests that angioplasty doesn’t increase life expectancy at all, not by a day, let alone by 10 years. And so something has given these patients false expectations for the benefit they’re going to receive.
There is one case in the history of cardiac surgery that was especially interesting. When surgeons developed their techniques of open-heart surgery in the 1950s and 1960s to treat very serious diseases in patients who are very sick. They knew that the procedures, because they require putting a patient on a heart-lung machine, carried a risk of brain damage. As they were doing this work in the 1950s and 1960s they had a whole series of patients who had strokes, who had seizures, who had other kinds of brain injury as a result of being on a heart-lung machine. Now, that was very clear by the 1950s-1960s. When doctors started doing coronary artery bypass surgery in the 1970s, the first surgical treatment that really produced impressive results for coronary artery disease, doctors ought to have known that there would be a risk of neurological or psychiatric side effects from this procedure, because this procedure, like other forms of heart surgery, required putting patients on a heart-lung machine. But for the first decade as doctors were doing this, there was very little knowledge of whether or not it was causing brain damage in patients. Doctors knew that that risk existed, they just weren’t studying it until the second decade of the procedure.