As I’ve argued on this blog before, “defensive medicine” — i.e., the claim that doctors routinely order useless medical tests and procedures solely to prevent the appearance of malpractice — is a myth. By and large, if a test or procedure won’t help prevent the patient from developing a serious complication, then it won’t help the doctor avoid a lawsuit if something goes wrong. Conversely, if a test or procedure would have helped the patient avoid a serious injury or complication, then, typically, the standard of medical care required the test or procedure anyway. Tort liability arises only when a doctor fails to do what a reasonable doctor would do and that failure causes the patient harm.

As I detailed again back in August, states that enacted draconian “tort reform” laws — which made it impossible for injured patients to pursue all but the most egregious cases of malpractice involving millions of dollars in damages — have not seen any reductions in their health care costs. Tort law and malpractice lawsuits simply don’t have much of an effect on health care and health care spending in the United States. That’s not surprising, considering that malpractice payments comprise a mere one-tenth of 1 percent (0.11 percent) of national health care costs. Plenty of unnecessary medical procedures are performed every day, but the motive for them is the obvious one: to make money.

However, the myth of defensive medicine just won’t go away, and on Christmas Day, a doctor under the pseudonym “Skeptical Scalpel, MD” posted that “defensive medicine is ubiquitous and not going to go away soon. Health care costs will continue to rise.” He recommends “a massive culture shift” among doctors and patients.

It’s unclear what kind of culture shift Dr. Scalpel has in mind, but the three examples of “defensive medicine” he gives suggest he wants doctors to scrap the differential diagnosis (the process of elimination that forms the backbone of clinical medicine) and stop reaching out to colleagues for advice on complicated cases.

Here’s his first example:

A young man with chest pain arrives in the ED. After taking a history and examining the patient, the ED MD is 99.99% certain that the patient did not have a heart attack or a pulmonary embolism. But he’s a little short of breath. He remembers a case of a fatal PE with only minimal shortness of breath, orders a blood gas and CT angiogram of the chest.

Any physician who is “99.99% certain” that patient did not suffer a heart attack is unfit to practice medicine. A patient history and physical examination will never give any physician enough information to be “99.99%” or 98.78% or 73.64% or 22.13% or 00.01% certain of anything. Clinical medicine doesn’t work that way. A doctor in that circumstance might reasonably be “pretty sure” or “confident” that the patient isn’t having a serious, urgent medical condition, but to ascribe any specific probability to it — much less a probability (“99.99%”) that is an incredible 3.89 standard deviations from the mean, with an equally surprising zero confidence interval — means that the doctor has utterly failed to understand the limits of a clinical medicine, and has wrongly presumed a level of mathematical precision to their analysis. 
Continue Reading Medicine Is Not An Exact Science (Countering A Defensive Medicine Myth)