Performance characteristics of the AxSYM D-dimer assay

Background: D-dimer testing is used to exclude thromboembolic disease in outpatients suspected of having deep venous thrombosis and pulmonary embolism. Methods: We evaluated 4 D-dimer assays for imprecision and method comparison and evaluated the AXSYM (R) method for interference, linearity, and reference interval. Method comparison testing was performed using the following methods: Abbott AxSYM, bioMerieux mini VIDAS (R), Diagnostica Stago STA Compact (R), and Biosite Triage (R) Meter Plus. Results: Total CVs for all methods ranged from 3.7% for the STA Compact to 17.3% for the Triage Meter. The AxSYM showed good agreement with the other methods with slopes ranging from 1.17 to 1.22 by Passing-Bablok regression and correlation coefficients >= 0.96. Interference from hemolysis, icterus, and lipemia had <7% deviation from the intended D-dimer concentration. Linearity had <= 11.5% deviation from target values. Conclusions: The AxSYM D-dimer assay provides a precise, rapid, and user-friendly method for D-dimer testing with good correlation to other methods. (C) 2008 Elsevier B.V. All rights reserved.