2.05.2009

Decision Making Errors

I was reminded of Jerome Groopman’s recent book, How Doctors Think, in blogging about medically trained writers yesterday. Groopman writes about the biases and errors that intrude on the decision making process of physicians. They occur far more often than is normally believed, sometimes with devastating consequences.

When I read the book, I was impressed by Groopman’s knowledge of recent cognitive research on heuristics and biases. His account is up-to date in all respects.

Some of the errors that physicians make can and do often occur to anyone. Groopman’s goal is to insure that when physicians shift from theoretical studies to practical applications, they are more mindful of the biases and uncertainty inherent in diagnosing patient illnesses.

He believes that overconfidence is one of the most common errors that physicians make, largely as result of their past diagnostic experiences. He writes: “You have to be prepared in your mind for the atypical and not so quickly reassure yourself, and your patient, that everything is okay.”

And later: “I learned from this to always hold back, to make sure that even when I think I have the answer, to generate a short list of alternatives. That simple strategy is one of the safeguards against cognitive errors.”

Taking issue with Malcolm Gladwell’s claims his wildly popular Blink: The Power of Thinking Without Thinking, Groopman cautions about making snap diagnostic judgments based on intuition.

He writes: “Much has been made of the power of intuition, and certainly initial impressions formed in a flash can be correct. But…intuition has its perils. Cogent medical judgments meld first impressions—gestalt—with deliberate analysis.”

In addition to Overconfidence some of the common inferential errors that Groopman discusses include the following:

Representative Error: Your decision is too strongly influenced by a prototype “so you fail to consider possibilities that contradict the prototype and thus attribute the symptoms to the wrong cause.”

Confirmation Bias
: Your decision is based on attending to supporting evidence exclusively, ignoring or “minimizing data that contradict it.

Commission Error: “This is the tendency toward action rather than inaction.”

Availability Bias
: Reaching a decision on the basis of a recent, vivid or easily recalled situation that is unrepresentative of case under consideration.

Groopman suggests that “most misguided care results from a cascade of cognitive errors.” He urges physicians to avoid premature closure, indeed, to be ever mindful of alternative accounts and keep inquiring “What else could it be?”

Everyone could benefit from such advice. It bears repeating: “Be ever mindful of alternative accounts and keep inquiring.”