BACKGROUND

Despite advances in “technological” medicine, the history and physical examination still provide the correct final diagnosis in the majority of cases^1,2 and remain the cornerstone of clinical medicine.³ Medical students spend a great deal of time learning these techniques. Students continue to be taught the long case “complete history and physical,” despite its inefficiency and errors. Bordage⁴ claims “you see what you are looking for,” and gathering further data fails to increase diagnostic accuracy. Educational research suggests diagnostic accuracy depends on both mastery of knowledge and sound problem solving strategies.⁵ Students can learn to problem solve more expertly by using schemes that assist storage and retrieval of clinical knowledge, rather than rote memorisation of lists and “dispersed” knowledge.^5,6

Diagnosis involves gathering clinical information and then refining the probability of a particular diagnosis after acquiring each piece of evidence. The elements of history and examination can be considered as individual “diagnostic” tests; thus Bayes’ theorem informs this decision making approach to diagnosis.^3,7

Even in familiar settings, clinicians, and students to a greater extent, make erroneous estimates of disease probability given the clinical features of the presentation.^8,9 Clinical textbooks seldom provide the frequency of …