Persuasion Collision
25th November 2011
As noted in the November 15, 2011 issue of Journal Watch, the US Preventative Services Task Force has issued a preliminary draft of its recommendations on Prostate Cancer Screening. The Task Force notes in its review of the scientific literature on prostate screening that:
1. Harms from screening (false-positives, overdiagnosis, unnecessary biopsies, etc.) are at least “small.”
2. Magnitude of treatment harms (adverse effects) is at least “moderate.”
3. The 10 year mortality benefit from screening is “small to none.”
4. The balance of benefits and harms for screening, therefore, has “no net benefit.”
The writer at Journal Watch then notes the negative response to these preliminary findings from the professional group, the American Urological Association, who claims the findings do “. . . a great disservice to the men worldwide who may benefit from the PSA test.”
How can two putative scientific groups look at the same evidence and come to such different conclusions? I’d look to persuasion theory rather than any science.
The Task Force is a group of selected experts who must operate according to a pre-established set of procedures and criteria for making their findings. They operate more like a jury in a legal proceeding. By contrast, the professional association operates by procedures and standards that can and will vary with who happens to be in the room. The AUA does not follow the same kind of data gathering, rule-bound analysis, and criteria application.
While the AUA would declare the following observation as null, void, and insulting, it is also transparently apparent that they have a financial stake in this decision that the Task Force does not. The Task Force preliminary finding would essentially stop a lucrative part of medical practice for many AUA members because they could no longer prescribe prostate screening as a routine recommendation. Consider this counterfactual. Imagine that AUA members could continue to recommend prostate screening, but would receive no payment for it. What do you think would be the behavior consequences?
This persuasion collision between Science and Practice illustrates in a different way my observation about death debates. No one is for death, so all discussion about life and death always operates from comparative advantages, that comparison between This or That and Less or More, but never Not or Maybe. No one makes Existential Cases in the life and death debates. Thus, you get this plain absurdity of an alleged scientific professional association fighting against scientific evidence. The only scientific way the AUA can attack the preliminary findings of the Task Force is to refute their science and they cannot do this.
Imagine all the cases of Dissonance Reduction among urologists and primary care physicians dealing with prostate screening. These preliminary findings represent a huge disconfirmation of strongly held beliefs, both scientific and financial. Some professionals will not be able to bridge the gap with reason and science and will instead cling to one or two studies that support their prior belief all the while steadfastly ignoring all that disconfirmation. You might consider this possibility as you peruse the website of Dr. William Catalona, the inventor of the PSA test and ardent critic of the Task Force findings. Is he a lone scientific voice of Truth crying in the wilderness against the Task Force or is his judgment confounded with his self concept and self esteem as the PSA inventor?
That’s human nature. And persuasion reveals and explains it. The only thing stronger than Falling Apples is Change We Cannot Believe In.