Many members of the prostate cancer community have a bone to pick with Prof. Gilbert Welch of Dartmouth College. … Yes, he is one of the leading advocates for the abolition of mass, population-based use of the PSA test to screen for risk of prostate cancer.
However, whatever one might think of Dr. Welch’s views about overuse of the PSA test, you would be wise to read his OpEd published today in the New York Times.
Dr. Welch asks a very simple question: When it comes to medicine and medical care, why don’t we make sure that what we think we know is actually correct? Most of medical practice today is, in fact, based not on what we know, but on what we think we know.
There have been many relatively recent examples from the world of healthcare and medicine which have clearly demonstrated that what we think we know is wrong. Here are just a few of the truly non-controversial ones:
- Throughout most of the lifetimes of anyone on the planet over 60 years of age, we thought that the “normal” temperature of a young adult human being when taken by placing a thermometer under the tongue was 98.6 °F (equivalent to 37.0 °C). This was based on an axiom laid down by Carl Wunderlich in the mid 19th Century. In 1992, Mackowiak et al. decided to actually test this axiom — consequently recommending that 98.6 °F (37 °C ) “should be abandoned as a concept relevant to clinical thermometry,” that 98.9 °F (37.2°C) should be regarded as a “normal” temperature in the early morning and that 99.9 °F (37.7 °C) should be regarded as the upper limit of the normal oral temperature range in healthy adults aged 40 years or younger. In fact, “normal” human temperatures vary significantly, and are known to depend on things like where in the body the temperature is measured, the time of day it is taken, and the age and level of activity of the individual.
- OTC cough syrups don’t work any better than a placebo in treating children (and they probably don’t work better than a placebo for adults either) and yet we consume them in billion dollar quantities every year.
- It is clear that spinal fusion surgery conducted to relieve back pain does not, in the majority of patients, work any better than physical therapy. Again, however, billions of dollars are spent every year on hundreds of thousands of these surgical procedures. Surgeons and patients both think that what they know is more accurate than what we really do know.
And of course examples like these don’t even touch such issues as whether vaccinations cause autism and whether cell phones cause brain cancer — both of which have been studied to death, with no good evidence to support either belief, but that doesn’t mean we are willing to accept that our beliefs aren’t true.
If we really want to be able to state, with accuracy, that “America has the best health care system in the world” (a recurrent claim based on absolutely no evidence at all), isn’t it about time that we set out to determine whether what we think we know is correct and to stop doing things that are very clearly wrong? At least we have managed to accept that things like prefrontal lobotomy and electroshock therapy are inappropriate ways to treat depression and other mental disorders! And someone even got a Nobel prize for the discovery of prefrontal lobotomy!
Much of the diagnosis and management of prostate cancer is still based on what we think we know. Think about it.