Introduction
There have been many advances in the area of patient safety since the publication of the
Institute of Medicine report “To err is human”,1
10 years ago. A major theme of this and
subsequent reports2
was that solutions should be sought within systems rather than blaming
individuals, and there has been a palpable shift of emphasis in that direction. 3,4 In the process of
finding system level solutions, however, important aspects of individual performance may have
been minimized or overlooked.5
Surprisingly few resources have been directed at how health
care providers think and feel, particularly in the process of clinical decision making. Yet, there is
considerable evidence that missed, delayed, or wrong diagnoses make up a significant proportion
of all medical errors and often will lead to major injury and suffering.6,7 Hitherto, the failure to
fully appreciate the impact of diagnostic error has been attributed to the obscure nature of the
processes that underlie clinical reasoning.8,9