One of the most common cognitive problems is faulty synthesis with premature closure, that is, the failure to continue to consider other diagnostic alternatives after forming an initial tentative diagnosis.
Other examples are anchoring bias, where one is locked into an aspect of the case; framing bias, where there is misdirection because of the way the problem was posed; availability bias, where things are judged by what comes readily to mind such as a recent experience; and confirmation bias, where one looks for confirmatory evidence of one’s preferred diagnosis while ignoring evidence to the contrary (Acad. Med. 2003;78:775-80).
Errors may be intuitive (automatic) or analytic (controlled). The former, which is the familiar reflexive, blink-of-an-eye diagnosis based on intuition, is the more common error. On the other hand, analytic processes are conscious, deliberate, slower, and generally more reliable, though more resource intensive.
One area deserving of attention: overconfidence and complacency. Critics have pointed out that some physicians are "walking ... in a fog of misplaced optimism" with regard to their confidence, failing to critically examine their assumptions, beliefs, and conclusions (metacognition), and generally underappreciating the likelihood that their diagnoses are wrong (Am. J. Med. 2008;121:S2-S23).
Dr. Tan is emeritus professor of medicine and a former adjunct professor of law at the University of Hawaii. This article is meant to be educational and does not constitute medical, ethical, or legal advice. It is adapted from the author’s book, "Medical Malpractice: Understanding the Law, Managing the Risk" (2006). For additional information, readers may contact the author at siang@hawaii.edu.