We can lock onto an early working diagnosis, “ignoring or failing to seek further data that might refute ones initial impression.” This is one of the most common cognitive errors, “premature diagnostic closure.” If we think about our thinking we might identify some common cognitive errors, patterns in the way we think that open holes for error. Then we can fix the holes, avoid the traps. Fixes can be “cognitive forcing strategies.”
The pace of an Emergency Room or primary doctor’s office is unavoidable, but sometimes risky. Even in the face of speed we can stop to consider–or force–alternative diagnoses. We can consciously, stop, gather our thoughts, and minimize Anchoring Error.
Anchoring Error (or Bias) — Refers to the common cognitive trap of allowing first impressions to exert undue influence on the diagnostic process. Clinicians often latch on to features of a patient’s presentation that suggest a specific diagnosis. Often, this initial diagnostic impression will prove correct, hence the use of the phrase “anchoring heuristic” in some contexts, as it can be a useful rule of thumb to “always trust your first impressions.” However, in some cases, subsequent developments in the patient’s course will prove inconsistent with the first impression. Anchoring bias refers to the tendency to hold on to the initial diagnosis, even in the face of disconfirming evidence.
Heuristic – Loosely defined or informal rule often arrived at through experience or trial and error (eg, gastrointestinal complaints that wake patients up at night are unlikely to be functional). Heuristics provide cognitive shortcuts in the face of complex situations, and thus serve an important purpose. Unfortunately, they can also turn out to be wrong.
On the other hand, fear of a mistake can freeze a physician. Many of us have the imago of an historic perfectionist mentor psychically seared into our subconscience. This can stall patient care, and reduce access to care as the doctor’s schedule is “full”–of overly detailed workups as he or she excessively avoids an “error.” Such inefficiency can restrict access to care–an error of justice (fewer patients get seen) and an economic inefficiency (costs to patients rise, and professional income can fall depending on the means of reimbursement). Quick and heuristic thinking is in tricky balance with avoidance of cognitive error.
Dr. Pat Croskerry’s 2003 paper (Annals of Emergency Medicine 41(1):110) is not available online–it was my introduction to these ideas. But a New Yorker article (Jan 29, 2007 full-text free online) gives background about Dr. Croskerry. Another, more theoretical paper by Croskerry is available full text online.