Misdiagnosis or delayed diagnosis occurs in 10-15 per cent of acute presentations, although fortunately only a tenth of these lead to serious consequences. But of concern is the fact that this figure hasn't changed in three decades, despite progress in clinical knowledge. Errors in diagnostic reasoning occur at the same rate in senior clinicians as they do in juniors, even though mistakes from poor examination or knowledge become less frequent as one gains experience. 

Compared to problems in maths or physics, diagnostic problems are thought of as ill-structured: because information isn't readily available, the problem can keep changing and often you're not certain you've reached a solution and are free to stop searching. Cognitive errors result from jumping to conclusions on the basis of intuition and incomplete information. There are a hundred different types of such bias. On this episode, the most common types will be discussed, as well as strategies to force a more considered process of diagnostic reasoning. 

In about two thirds of cases, systems problems like design and workflow contribute to diagnostic error. These will be discussed in the second episode of this series. 

Guests
Dr Nicolas Szecket FRACP (Auckland City Hospital)
Dr Arthur Nahill FRACP (Auckland City Hospital). 

Production
Written and produced by Mic Cavazzini. Music courtesy of Mystery Mammal ('To be Decided,' 'Data'), RGIS VICTOR ('Lampagisto') and Lobo Loco ('Spook Castle'). Image courtesy of iStock. The production manager was Anne Fredrickson.

Editorial feedback for this episode was provided by RACP members Dr Paul Jauncey, Dr Alan Ngo, Dr Katrina Gibson. Dr Marion Leighton, Dr Michael Herd and Dr Joseph Lee.

Please visit the RACP website for a transcript embedded with citations. Fellows of the College can claim CPD credits for listening and additional reading.