D-dimer value more than 3.6 μg/ml is highly possible existence deep vein thrombosis.

OBJECTIVE The present study aimed to establish whether a more optimal cutoff value for D-dimer testing could definitively rule out acute deep vein thrombosis (DVT). METHODS Between April 2009 and March 2010, 190 referral patients suspected to have DVT were assessed by the D-dimer assay. Additionally, ultrasonography (US) and computed tomography (CT) imaging were performed to detect thrombosis. RESULTS DVT was identified in 47 patients (24%). The average D-dimer level in patients with DVT was 17.6±22.4 μg/ml, and was significantly lower (p=0.035),] at 2.7±4.2 μg/ml, in those without DVT. On the basis of receiver operating curve analysis, the specificity of the D-dimer for diagnosing DVT increased from 40% to 78.3%, and its sensitivity reached 93.8%, when the cutoff value for the assay was set at 3.6 μg/ml. CONCLUSIONS D-dimer value over 3.6 μg/ml was highly prognostic for DVT.