The Rational Clinical Examination is a series published by the Journal of the American Medical Association (JAMA).

In each issue of the series, a specific clinical question is posed (such as "Is This Patient Having a Stroke?") and the current evidence that is needed to answer the question is presented. Some of the pieces of evidence presented are the specific likelihood ratios of historical features and physical findings, which are treated like diagnostic tests. These LRs help guide the clinical suspicion of disease, by providing values that help determine the patient's post-test probability of the disease in question.

JAMA: The Rational Clinical Examination

Lets look at an example