Diagnosis accuracy of a new challenger for thrombosis exclusion, the Stratus CS DDMR.

Background: The diagnostic accuracy of a new Point of Care, rapid and quantitative D-dimer assay (Stratus CS DDMR from Dade Behring) was evaluated.

Methods: Vidas test from bioMerieux was used as reference method in 279 patients recruited from a management study in progress in our institution.

Results: Both assays show comparable reproducibility (2.9% with the Stratus CS DDMR and 4.4% with the D-dimer Vidas in the cut-off range) and good correlation (R(2)=0.9057). The overall test performance as assessed by the area under the curve of the ROC curves is 0.801 for the Stratus CS DDMR assay and 0.798 for the D-dimer Vidas assay. By using assay regression curves, likelihood ratios or test agreement approaches, a 440-450 ng/ml value is evidenced as the threshold value for the Stratus CS DDMR, which nears at best the performances of the D-dimer Vidas 500 or 550 ng/ml threshold value. This proposed exclusion value ensures a 95% sensitivity and a 45% specificity. The few false negative results using the two assays only evidenced sub-popliteal thromboses, that would not have been considered as having thrombosis if an above-the-knee test had been performed. In these conditions, sensitivity would have been 100%.

Conclusions: A new quantitative D-dimer assay, the Stratus CS DDMR, demonstrated performances comparable with those of the DD Vidas test.