Blog | Friday, July 13, 2018

The danger of pronouncements in medicine


“Experts” mean to improve health. They have great intentions, but we all know what is paved with good intentions.

This week I twice checked my blood pressure on a machine at our grocery store. The first time my blood pressure with 134/82 and the machine told me I had an elevated blood pressure. The second time it was 124/78 and it told me that my blood pressure was elevated. I was very pleased with my blood pressure, and astonished. The machine justifies these interpretations because a group of “experts” wrote and published a guideline pronouncement that redefined almost everyone as either being hypertensive or at least elevated.

That same group championed a flawed risk calculator that greatly overestimates my risk of coronary artery disease. As soon as they release risk calculator (now touted for both statin use and hypertension treatment) Dr. Nissen wrote this opinion piece, “Risk Calculator for Cholesterol Appears Flawed.”

Annals of Internal Medicine includes a very complex, careful alternative to that risk calculator, “Clinical Implications of Revised Pooled Cohort Equations for Estimating Atherosclerotic Cardiovascular Disease Risk.”

Results:
The 2013 PCEs overestimated 10-year risk for atherosclerotic CVD by an average of 20% across risk groups. Misestimation of risk was particularly prominent among black adults, of whom 3.9 million (33% of eligible black persons) had extreme risk estimates (<70% or >250% those of white adults with otherwise-identical risk factor values). Updating these equations improved accuracy among all race and sex subgroups. Approximately 11.8 million U.S. adults previously labeled high-risk (10-year risk ≥7.5%) by the 2013 PCEs would be relabeled lower-risk by the updated equations.
The authors are incredibly polite in their discussion. I refuse to play the politeness game.

This example is only one in a series of many such overreaching pronouncements.

Why does this happen? We work in a world that champions evidence-based decision making. We believe that evidence exists without bias. But cognitive psychologists have taught us (just as they have taught economists) that data require interpretation. As Dr. Verghese recently said, “Medicine is messy and complicated, because humans are messy and complicated.” Yet our experts try to impose simple rules for patient care.

Confirmation bias leads many groups to focus on possible benefits and minimize likely risks. Labeling someone incorrectly as having hypertension or needing a statin is a major mistake. But yet the experts champion a flawed calculator and flawed targets. Obviously these pronouncements really aggravate me. And I do not believe that I am unique among rational physicians.

Please decrease these pronouncements. Save your guidelines and recommendations to situations that are very clear. Embrace the controversies and allow physicians to consider multiple patient considerations when making decisions with their patients.

If you are skeptical of my rant, just consider how many dueling guidelines we have. Guidelines have assumed almost religious fervor in some quarters, yet when panels disagree on the recommendations we are placed in an impossible situation.

Save the money and time spent on crafting these missives and explain why our decision making is appropriately messy. Embrace the messiness. We all know that the emperor has no clothes. Do not pretend otherwise.

db is the nickname for Robert M. Centor, MD, MACP. db stands both for Dr. Bob and da boss. He is an academic general internist at the University of Alabama School of Medicine, and the former Regional Dean for the Huntsville Regional Medical Campus of UASOM. He still makes inpatient rounds regularly at the Birmingham VA and Huntsville Hospital. His current titles are Professor-Emeritus and Chair-Emeritus of the ACP Board of Regents. This post originally appeared at his blog, db's Medical Rants.