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.
Freyburger
Geneviève
G
Laboratoire d'Hématologie, Hôpital Pellegrin, 33076 Bordeaux cedex, France. genevieve@chu-bordeaux.fr
Reboul
Marie-Pierre
MP
Labrouche
Sylvie
S
Saillour
Florence
F
Grenier
Nicolas
N
D000368:Aged; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems; D011237:Predictive Value of Tests; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020246:Venous Thrombosis / Q000097:blood / Q000175:diagnosis*
D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D