A comparison of three rapid D-dimer methods for the diagnosis of venous thromboembolism

Authors


Dr Kovacs is an Internal Scholar, Department of Medicine, University of Western Ontario. Dr Wells is a Canada Research Chair.Correspondence: Dr Michael J. Kovacs, Rm. 2760, Phase 1, London Health Sciences Centre, 800 Commissioners Rd. E. London, ON N6A 4G5, Canada. E-mail: michael.kovacs@lhsc.on.ca

Abstract

We compared three rapid d-dimer methods for the diagnosis of venous thromboembolism. Patients presenting to four teaching hospitals with the possible diagnosis of deep vein thrombosis or pulmonary embolism were investigated with a combination of clinical likelihood, d-dimer (SimpliRED) and initial non-invasive testing. Patients were assigned as being positive or negative for deep vein thrombosis or pulmonary embolism based on their three-month outcome and initial test results. The three d-dimer methods compared were: (a) Accuclot d-dimer (b) IL-Test d-dimer (c) SimpliRED d-dimer. Of 993 patients, 141 had objectively confirmed deep vein thrombosis or pulmonary embolism. The sensitivity of SimpliRED, Accuclot and IL-Test were 79, 90 and 87% respectively. All three d-dimer tests gave similar negative predictive values. The SimpliRED d-dimer was found to be less sensitive than the Accuclot or IL-Test. When combined with pre-test probability all three methods are probably acceptable for use in the diagnosis of venous thromboembolism.

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