Patients
Records of patients who presented to the ED of a large Australian metropolitan general hospital within twelve calendar months who underwent D-dimer testing were reviewed. Patients were included if they were over 16 years of age and had a D-dimer assay for suspected PE. Patients who had DD testing for suspected deep vein thrombosis (DVT) without PE, or for explicitly other reasons – such as assessment for disseminated intravascular coagulation after snake bites – were excluded.
Patient records were reviewed to re-calculate a pre-test probability based on the Revised Geneva Score (RGS – as summarised by Wong et al9). While the Wells score is more widely used and is well validated10, it is difficult to calculate post hoc, especially as a major component of this score – that PE is the most likely diagnosis – is subjective. RGS, by contrast, uses objective and quantifiable measures, as summarised in Table 1. Both clinical scoring systems are reported to have similar accuracy9, 11.