The New York Times recently had one of their periodic debates: When Medical Experts Disagree.
This debate actually centers on the current cholesterol guidelines, but the problem recurs often. Different experts look at the data and develop differing opinions. We see this with prostate screening, mammography, and treatment decisions.
As one reads the varying opinions in this debate, an understanding of the affect heuristic makes the debate transparent. When we like something, we overestimate the value and underestimate the risks and costs. This explains most conflicts of interest, and importantly conflicts of interest are not just pharmaceutical.
The experts writing the cholesterol guideline are heavily invested in the cholesterol hypothesis. The higher the cholesterol the worse the patient will do. Amazingly, the data made clear that only statins have excellent outcome data, so the panel dropped cholesterol goals for primary prevention and high yield secondary prevention (patients between 40-75 with type II diabetes mellitus or very high LDL cholesterol).
The controversy rests then on primary prevention. The experts like lowering cholesterol. They have accepted the data that statins trump every other drug class, and that other drug classes do not have sufficient outcome data to either add to statins or use alone. They know that primary prevention does decrease cardiac events. Because they like preventing cardiac events, they favor an aggressive approach to primary prevention.
Many other physicians worry about treating very large numbers of patients with a drug that both has significant costs and side effects (mostly muscle pain). These physicians are not as enamored with statins, unless the patient has very clear indications.
As one reads the various debaters, one can understand their contributions as resulting from the affect heuristic. One debater sees the pharmaceutical influence as a major evil — thus blames the pharmaceutical conflicts of interest (while apparently ignoring other conflicts). One debater clearly focuses on drug side effects, and cautions against using any new drugs, unless the new drug has proven major benefits.
Seeking truth where there is no truth will always frustrate physicians and patients. We have to balance risks, costs and benefits, and generally make these estimate with incomplete information. For rarely can we have complete information. We want to worship at the altar of evidence-based medicine, but we still must assess values, and values will always contain a subjective component.
Robert Centor is an internal medicine physician who blogs at DB’s Medical Rants.
