Misdiagnosis may be caused by faulty tests or patient misidentification, but it is more often the result of erroneous thinking on the part of the physician, according to Jerome Groopman, MD, in a Boston Globe column.

Physicians make several types of critical thinking errors, according to Groopman. They include:

• Attribution errors, in which the physician makes a diagnosis based on a stereotype or usual outcome determined by a symptom
• Anchoring errors, in which the physician commits to an initial diagnosis and does not consider other possibilities
• Confirmation bias, in which the physician discounts data that suggests a different diagnosis than the one at which he or she has already arrived.

Groopman suggests physicians keep an open mind with every diagnosis and consider all evidence before making a final determination.