Comparison of the Diagnostic Performance of an AgeAdjusted and a Conventional Threshold with a Point-of-Care D-Dimer Test in Ambulatory Patients with suspected VTE

Patients commonly present as emergencies with symptoms suspicious for venous thromboembolism (VTE), either pulmonary embolism (PE) and/or a deep vein thrombosis (DVT). Quantitative D-dimer testing is recommended in patients considered at low-to-moderate risk based on a clinical prediction tool. 1 Conventionally, a cut-off of 500 ng/ml fibrin equivalent units (FEU) has been employed, but improved diagnostic performance has been reported using an ageadjusted threshold. 2,3 Point-of-care (POC) D-Dimer testing in the ambulatory setting conveys many benefits but, though tentatively recommended by national guidance in the United Kingdom,4,5 the performance of an age-adjusted POC Ddimer strategy is not well described. In an ambulatory population with suspected VTE, we aimed to compare the diagnostic performance of a POC D-dimer test using conventional and age-adjusted thresholds.