A paper that changed my practice, twice

As a newly qualified preregistration house officer, alone on an orthopaedic ward one weekend, I was asked to review a patient complaining of pleuritic chest pain. This meant considering a short list of differential diagnoses to treat or exclude. Among these, of course, was pulmonary embolism, hence a D-dimer test seemed relevant. I can't remember much about this specific encounter, but I know I thought, worried, and procrastinated for as long as it took for the blood results to come back. Then I bleeped the medical registrar to ask what to do about the abnormal D-dimer test result.

The most memorable part of the encounter was …