• Vol. 42 No. 1, 33–41
  • 15 January 2013

Cognitive Aspect of Diagnostic Errors



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Diagnostic errors can result in tangible harm to patients. Despite our advances in medicine, the mental processes required to make a diagnosis exhibits shortcomings, causing diagnostic errors. Cognitive factors are found to be an important cause of diagnostic errors. With new understanding from psychology and social sciences, clinical medicine is now beginning to appreciate that our clinical reasoning can take the form of analytical reasoning or heuristics. Different factors like cognitive biases and affective influences can also impel unwary clinicians to make diagnostic errors. Various strategies have been proposed to reduce the effect of cognitive biases and affective influences when clinicians make diagnoses; however evidence for the efficacy of these methods is still sparse. This paper aims to introduce the reader to the cognitive aspect of diagnostic errors, in the hope that clinicians can use this knowledge to improve diagnostic accuracy and patient outcomes.

It was an unusually busy ward round. The newly promoted registrar was keen to review the patients handed over to him. But there were constant distractions from the other
things he needed to attend to quickly. The patient, Madam Sumar was referred by her family doctor for chest pain with shortness of breath; ischaemic chest pain was his concern. The junior doctor who saw her planned for investigation of possible ischaemic heart disease. The young registrar reviewed her, and concurred with his colleague’s assessment. But Madam Sumar was unhappy with her assigned ward and complained repeatedly; she also had other vague complaints such as giddiness and pain in her leg. The registrar wanted to move on to his next duty. Four hours later, Madam Sumar was dead from pulmonary embolism.

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