A strange “health care” drama plays out daily in our clinics and hospitals. A healthy person has a medical test done (even though he or she is healthy): a blood test, a chest x-ray or mammogram, maybe an ultrasound of some body part. The test comes back abnormal. The patient (for she has now gone from being a healthy person to being a patient) is struck with worry, and undergoes a further round of testing to determine whether the initial, “screening” test was accurate. This more invasive, risky definitive testing causes the patient pain, complications, infections, further procedures to fix the complications. But the testing shows that the original screening test was wrong, and the patient is relieved of their worry and overcome with a sense of gratitude: “Yes, the follow-up surgery was painful, but at least it’s not cancer.” However, notice what caused the worry in the first place: not some symptom that they were experiencing, but a test that was performed on a healthy person. What a marvelous bit of sorcery: we take a happy patient, create unnecessary worry, then win their undying gratitude by performing risk-laden procedures on them to remove their worry!
There is something very intuitive about the concept that detecting a disease (especially cancer) early leads to better outcomes, that screening tests are inherently good. Yet when one studies the actual outcomes of implementing mass screening programs in a population of people who have no signs or symptoms of a particular disease, one finds to one’s surprise that, not infrequently, more people are harmed by our screening test than are helped (See: PSA testing, carotid ultrasounds, annual stress tests, etc). This harm may take many forms: worry, invasive procedures with all the risk they bring, radiation exposure, disfiguring treatments, stroke, even death. Yet there is no shortage of promoters of various tests that capitalize on our intuition that “More testing is better.”
In steps the United States Preventive Services Task Force (or USPSTF), a group of experts in preventive medicine and primary care (since it is mostly primary care providers who order screening tests). Their task is to examine the scientific evidence of the potential risks and harms of preventive strategies like screening tests, and to make recommendations based solely on that evidence. They strive to use the best scientific data available to benefit the most people possible. Even when their recommendations are unpopular (because they go against our intuition that more screening is better), they have a large effect on what tests are performed — and what tests insurance will pay for.
This week the USPSTF recommended against screening for thyroid cancer in people without symptoms. The data show that screening has found lots of thyroid cancer that never would have been found otherwise. The data also show that screening has not produced a reduction in death from thyroid cancer or an increase in quality of life. What it has produced is an increase in harms, such as injuries to vital nerves from the increase in thyroid surgery. Who knew?
Now there is legislation pending in Congress proposing that “stakeholders” — that is, specialists and industry representatives — be included in the membership of the USPSTF. This is a very bad idea. Consider: What do specialists like thyroid surgeons (who are not experts in screening for thyroid cancer; rather, their livelihood is tied to operating for it) or drug and device manufacturers (who sell the tests and ultrasound machines used to screen for thyroid cancer) add to the USPSTF’s process? The main thing “stakeholders” (that is, people with a financial interest in seeing the test done) add is a conflict of interest. Whatever difference such “stakeholders” make would be tilted to the advantage of the few who stand to profit from the screening, and to the detriment of the many in the population who would be harmed from the screening. The USPSTF’s work must not be transformed from a transparent procedure that seeks to minimize harm into a get-rich-quick scheme.