The Problems with Evidence Based Medicine
“EBM is based on a statistical blunder: the assumption that a population value can be applied to one specific individual. This is known as the ecological fallacy . . . it is fundamentally incorrect to apply the results of large-scale trials to individual patients. Despite this, the EBM myth is that individual patients should be treated according to a gold standard of population statistics. A doctor needs to treat every patient as a person with a unique problem . . . A doctor practicing purely according to statistical expectations will inevitably harm patients.”
Evidence Based Medicine or EBM is a huge buzz word right now in medicine. With the government gearing up to pay doctors more who use EBM, physicians who have known about these changes for years are taking notice. There’s just one little problem as the authors of Tarnished Gold: The Sickness of Evidence-based Medicine point out. Using EBM over medical best judgement harms patients.
Take for example the large studies that are performed on many common drugs. Clinically irrelevant findings are often magnified into statistically significant changes by studying huge populations and substituting relative risk for absolute risk. Take for example many of the studies that support the use of cholesterol lowering drugs to prevent heart attacks. The absolute risk reduction when thousands of people are studied is a measly 1%. Since no one in their right mind would prescribe or take a drug that reduced their risk of heart attack by 1%, the drug companies creatively inflated the statistics like a middle aged man popping Viagra by advertising a relative risk reduction. So if the drug lowers the five-year incidence of heart attack from 4 percent to 3 percent for an absolute risk reduction of 1 percent, it’s reported as a s a 25 percent relative risk reduction! Who wouldn’t take a drug that lowers heart attack risk by 25%? What’s amazing is that when I discuss this with physician colleagues, few are aware of this statistical slight of hand. However, now these same physicians will be paid more or less for adhering or not adhering to this mathematical tomfoolery.
You may remember my recent story of my wife’s mystery illness. What we encountered was specialist after specialist beaten into submission by the silly adherence to EBM. Not a one could think outside the box or even work their way through a simple differential diagnosis to immediately recognize that my wife’s presenting complaints didn’t fit inside the check box medicine that the EBM fanatics had taught them. In fact, while it’s hard for patients to see, as a physician, medicine’s reliance on EBM has now reached the point of fanaticism. Like cults proselytizing on a street corner, many of my colleagues advocate a blind adherence to EBM.
The upshot? We used to teach our physicians how to think, but that wasn’t so good for pharma. Physicians who could think for themselves got to decide which drug they prescribed based on the unique patient in front of them. It’s a much more efficient business model if physicians are financially dinged for not using the results of studies on a population with artificially magnified results which actually show clinically meaningless, barely there changes. After all, if you’re a pharma executive, original thought is so overrated!