title: The use of a fixed high sensitivity to evaluate five D-dimer assays' ability to rule out deep venous thrombosis: a novel approach.
abstract: Suspected deep venous thrombosis (DVT) is difficult to refute without complex diagnostic algorithms and expensive testing. We analysed five D-dimer assays' utility for exclusion of suspected DVT during a prospective clinical cohort trial, choosing a highly sensitive cut-off value at which to compare the assays. Assays were performed on 436 consecutive patients who were referred with symptoms that suggested a first episode of DVT. Venous thromboembolism (VTE) was defined as positive findings on comprehensive duplex ultrasonography or any episode, or complication of VTE detected during 3 months of clinical follow-up. All five assays were performed in 377 patients. At a highly sensitive cut-off value, all five assays reliably excluded DVT in the study population. While the choice of a highly sensitive cut-off value reduced the specificity of all the assays, the change in specificity differed between tests. Our findings suggest that a second-generation D-dimer assay could be used as a stand-alone test to rule out suspected DVT when a highly sensitive cut-off value is chosen. These findings should be subjected to a prospective management study, as a small reduction in sensitivity from our findings could result in a clinically relevant decrease in negative predictive value.
authors.affiliation: Department of Internal Medicine, University of Utah, Salt Lake City, UT 84143, USA. ldssteve@ihc.com
authors.forename: Scott M
authors.initials: SM
authors.lastname: Stevens
authors.forename: C
authors.initials: C
authors.lastname: Gregory Elliott
authors.forename: Scott C
authors.initials: SC
authors.lastname: Woller
authors.forename: Liang
authors.initials: L
authors.lastname: Li
authors.forename: Sterling T
authors.initials: ST
authors.lastname: Bennett
authors.forename: Marlene
authors.initials: M
authors.lastname: Egger
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Snow
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014463:Ultrasonography; D020246:Venous Thrombosis / Q000175:diagnosis* / Q000000981:diagnostic imaging
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D