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

We compared three rapid D-dimer methods for the diagnosis of venous thrombo embolism. Patients presenting to four teaching hospitals with the possible diagnosis of deep vein thrombosis or pulmonary embolism were investigated w ith a combination of clinical likelihood, D-dimer (SimpliRED) and initial n on-invasive testing. Patients were assigned as being positive or negative f or deep vein thrombosis or pulmonary embolism based on their three-month ou tcome 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 patien ts, 141 had objectively confirmed deep vein thrombosis or pulmonary embolis m. The sensitivity of SimpliRED, Accuclot and IL-Test were 79, 90 and 87% r espectively. All three D-dimer tests gave similar negative predictive value s. The SimpliRED D-dimer was found to be less sensitive than the Accuclot o r IL-Test. When combined with pre-test probability all three methods are pr obably acceptable for use in the diagnosis of venous thromboembolism.