Many internists love Sherlock Holmes.  Arthur Conan Doyle was a physician who stressed observation and reasoning.  As one carefully reads Sherlock Holmes and his successors, one can learn much about the reasoning process.

We currently have two school of reasoning in cognitive psychology.  One school, popularized by Kahneman and Tversky, focuses on diagnostic errors.  Many internists have loved this school.  Their work provides us labels and explanations for our misses.  We warn our learners about these errors.  However, one should question whether knowing the types of errors helps us develop expertise.

Naturalistic decision making (with Gary Klein as probably its most well known practitioner) describes a field dedicated to understanding expertise.  Thus we have the contrast of approach clinical reasoning either from a negative (error) approach or a positive (expertise) approach.  

These viewpoints are not mutually exclusive.  

For those who have great interest, I highly recommend Conditions for Intuitive Expertise: A Failure to Disagree

Another worthwhile discussion – Strategic decisions: When can you trust your gut?

Klein values intuition but does not rely on it alone.  He states:

It depends on what you mean by “trust.” If you mean, “My gut feeling is telling me this; therefore I can act on it and I don’t have to worry,” we say you should never trust your gut. You need to take your gut feeling as an important data point, but then you have to consciously and deliberately evaluate it, to see if it makes sense in this context. You need strategies that help rule things out. That’s the opposite of saying, “This is what my gut is telling me; let me gather information to confirm it.”

As I read Sherlock Holmes and other detectives, this describes them well.  As I talk to excellent clinicians, this describes them well.  When one first encounters a complex diagnostic problem thoughts occur.  Klein interestingly has found that experts entertain one diagnosis at at time.  They check that one rather than considering multiple diagnoses at once.  

When intuition drives us towards a diagnosis, we start the process of confirmation.  We only err when we ignore data that argue against confirmation.

Klein also has a wonderful concept of the premortem evaluation.  When considering a diagnosis and subsequent treatment, one should image what could go wrong.  If one simulates mentally a potential major problem, then we must seek out more information.

So what is this post really about.  We in medical education must study cognition, become aware of our own cognition, and teach these thought processes to our learners.  We must role model excellence if we want our learners to become excellent.

And a good place to start is the mystery novel, TV show or movie.  Try to get a copy of this excellent article – White coats and fingerprints: diagnostic reasoning in medicine and investigative methods of fictional detectives