title: Combining clinical risk with D-dimer testing to rule out deep vein thrombosis.
abstract: We sought to determine whether the combination of low-intermediate clinical risk of acute lower extremity deep vein thrombosis (DVT) and negative ELISA D-dimer assay can eliminate the need for duplex ultrasonography. Three hundred thirty-six patients prospectively underwent clinical risk stratification (low, intermediate, and high), D-dimer testing, and duplex ultrasonography. Thirteen of 145 intermediate-risk patients had acute DVT; 11 (85%) had a positive D-dimer. Two of 118 low-risk patients had acute DVT; both had a positive D-dimer. Intermediate-high risk stratification alone had sensitivity of 93.9% (95% CI: 80.3-98.3%) and a NPV of 98.3% (95% CI: 94.0-99.5%) for acute DVT. For all patients, a positive D-dimer alone had a sensitivity of 93.9% (95% CI: 80.3-98.3%) and a NPV of 98.6% (95% CI: 95.1-99.6%). The combination of D-dimer and intermediate-high risk classification had a sensitivity of 100% (95% CI: 89.4-100%) and a NPV of 100% (95% CI: 98.9-100%). In suspected acute lower extremity DVT, the combination of intermediate-high clinical risk and positive D-dimer has a high sensitivity and NPV, possibly eliminating the need for duplex ultrasound in this group of patients.
authors.affiliation: The Mercy Hospital of Pittsburgh, Pittsburgh, Pennsylvania 15219, USA.
authors.forename: Kaveh
authors.initials: K
authors.lastname: Ilkhanipour
authors.forename: Allan B
authors.initials: AB
authors.lastname: Wolfson
authors.forename: Heather
authors.initials: H
authors.lastname: Walker
authors.forename: Jason
authors.initials: J
authors.lastname: Cillo
authors.forename: Susan
authors.initials: S
authors.lastname: Rolniak
authors.forename: Pamela
authors.initials: P
authors.lastname: Cockley
authors.forename: David
authors.initials: D
authors.lastname: Mooradian
authors.forename: Sandra
authors.initials: S
authors.lastname: Kaplan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004487:Edema / Q000175:diagnosis; D004636:Emergency Service, Hospital; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D020246:Venous Thrombosis / Q000175:diagnosis*
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D