Rapid D-dimer testing and pre-test clinical probability in the exclusion of deep venous thrombosis in symptomatic outpatients.
We assessed the performance of three rapid D-dimer tests (Auto Dimertest, VIDAS and Tinaquant) in combination with a pretest clinical probability model for deep venous thrombosis (DVT) in 106 consecutive outpatients with suspected DVT. Contrast venography or colour-coded duplex ultrasonography demonstrated the presence of DVT in 47 patients (14 distal DVT and 33 proximal DVT). First, we assessed the accuracy indices for different cut-off levels of the rapid D-dimer tests. Sensitivity was found to be 97.9-100%, negative predictive value (NPV) was 96.3-100%, and the exclusion rate was 24.5-31.1%. Next, the patients were grouped according to the pre-test clinical probability model in categories with low, moderate or high probability. In patients with a low pre-test probability, DVT would have been directly ruled out and the patients would not have undergone further investigations. In patients with a moderate probability, D-dimer testing and, in the case of a positive result, objective testing would have been performed and, in the case of a negative result, they would have been ruled out of having DVT. Patients with high probability would directly have undergone objective tests for DVT. The combination with the pre-test clinical probability model improved the exclusion rate (43.5-44.6%), whereas sensitivity (97.5-100%) and NPV (97.6-100%) remained roughly unchanged. The combination of rapid D-dimer tests with a pre-test clinical probability model may help to reduce unnecessary work-up in patients with suspected DVT.
Fünfsinn
N
N
Central Haematology Laboratory, University Hospital, Inselspital Bern, Switzerland.
Caliezi
C
C
Biasiutti
F D
FD
Korte
W
W
Z'Brun
A
A
Baumgartner
I
I
Ulrich
M
M
Cottier
C
C
Lämmle
B
B
Wuillemin
W A
WA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D010690:Phlebography; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013924:Thrombophlebitis / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D013997:Time Factors; D018615:Ultrasonography, Doppler, Color; D018616:Ultrasonography, Doppler, Duplex
D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D