Evaluation of the Simplify D-dimer assay as a screening test for the diagnosis of deep vein thrombosis in an emergency department.
OBJECTIVE
To evaluate the use in an emergency department of a new D-dimer assay (Simplify D-dimer) as a screening test for deep vein thrombosis (DVT).


METHODS
187 outpatients with clinical features suspicious of acute DVT were entered into this study. A Simplify D-dimer test was performed in the emergency department on all patients. A SimpliRED D-dimer test and a semi-automated latex agglutination assay (Auto-D-dimer 700 on a Thromboscreen 400C analyser) were performed in the haematology laboratory. All patients were investigated with contrast venography to confirm or exclude the diagnosis of DVT.


RESULTS
The Simplify test had a sensitivity of 94.1% and a negative predictive value (NPV) of 94.8%. These results compared favourably with the SimpliRED test (sensitivity 74.5%, NPV 89.7%) and the latex agglutination assay (sensitivity 90.2%, NPV 92.2%). This increased sensitivity was at the cost of a lower specificity, the specificity of the three d-dimer tests being Simplify 40.4%, SimpliRED 83.1%, and latex agglutination 43.4%.


CONCLUSIONS
Simplify proved to be a rapid and easy to use test and may be useful for use in the emergency department as part of a diagnostic algorithm for deep vein thrombosis. Further larger scale studies are needed.
Neale
D
D
Emergency Department, Prince Charles Hospital, Merthyr Tydfil, Mid Glamorgan, Wales CF47 9DT, UK.
Tovey
C
C
Vali
A
A
Davies
S
S
Myers
K
K
Obiako
M
M
Ramkumar
V
V
Hafiz
A
A
D000208:Acute Disease; D000933:Antifibrinolytic Agents; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products; D006801:Humans; D007841:Latex Fixation Tests; D008297:Male; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D020246:Venous Thrombosis / Q000175:diagnosis*
D000933:Antifibrinolytic Agents; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D