Improving medical diagnoses by understanding how they are made

While a correct diagnosis is essential to appropriate patient management, scant attention is paid to the processes by which medical diagnoses are arrived at. While mismanagement may arise from a lack of relevant knowledge or the misuse of available data, this is probably uncommon. In many cases in which diagnistic errors occur, an initial faulty triggering of an inappropriate hypothesis is followed by a premature closure, excluding the search for further data that might be relevant to the diagnostic process. Often this is followed by anchoring, so that even when additional relevant data becomes available, the new information is ignored, and the original, faulty diagnosis is retained. Disturbingly, these errors may not be a reflection of lack of training or experience, and must be guarded against by even the most senior clinicians. Perhaps a systematic review of diagnostic accuracy should become a routine part of institutional quality assurance programmes.