Comparison of high specificity with standard versions of a quantitative latex D-dimer test in the assessment of community pulmonary embolism HaemosIL D-dimer HS and Pulmonary Embolism

• Published in: Thrombosis research Vol. 124; no. 2; pp. 230 - 235
• Main Authors: THAN, Martin P, HELM, Jennifer, CALDER, Kristi, ARDAGH, Michael W, SMITH, Mark, FLAWS, Dylan F, BECKERT, Lutz
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 01.06.2009
• Subjects: Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Emergency Service, Hospital; False Positive Reactions; Female; Fibrin Fibrinogen Degradation Products - standards; Follow-Up Studies; Humans; Interviews as Topic; Male; Medical sciences; Middle Aged; New Zealand - epidemiology; Pilot Projects; Pneumology; Predictive Value of Tests; Prevalence; Prospective Studies; Pulmonary Artery - diagnostic imaging; Pulmonary Embolism - diagnosis; Pulmonary Embolism - diagnostic imaging; Pulmonary Embolism - epidemiology; Pulmonary hypertension. Acute cor pulmonale. Pulmonary embolism. Pulmonary vascular diseases; Radiography; Reference Standards; Sensitivity and Specificity; Time Factors; Vascular disease; Pulmonary embolism; Sensitivity; Specificity; Respiratory disease; D-dimer; Cardiovascular disease; D dimer; Thromboembolism; Thrombosis; Comparative study
• ISSN: 0049-3848; 1879-2472
• DOI: 10.1016/j.thromres.2008.10.018

D-dimer assays are sensitive but have poor specificity. False positive results lead to extra imaging and hospital admissions. To make a pilot comparison of the diagnostic accuracy of the standard quantitative latex HemosIL D-dimer assay with a newer HemosIL D-dimer HS version designed to have improved specificity. PATIENTS / METHODS: Consecutive patients presenting from the community to an Emergency Department that were investigated for suspected pulmonary embolism using a D-dimer test were included in the study. Standard and D-dimer HS tests were performed. Pulmonary Embolism was diagnosed on the basis of imaging studies or post-mortem at any time from presentation to 90 days thereafter. The prevalence of Pulmonary Embolism was 4.5% (18/402). The sensitivity, specificity, negative predictive value, and positive predictive value for the standard quantitative D-dimer test was 100% (81.5 - 100.0), 49.2% (44.1 - 54.3),100% (98.1 - 100.0), and 8.5% (5.1 - 13.0), respectively, and 100% (81.5 - 100.0), 58.3% (53.2 - 63.3),100% (98.4 - 100.0), and 10.1% (6.1 - 15.5), for the D-dimer HS test. There were 35 (16%) fewer 'false positives' using the D-dimer HS assay compared with the standard assay. D-dimer HS has superior specificity to the standard quantitative D-dimer test without any loss of sensitivity. The generation of fewer false positive results should lead to less unnecessary diagnostic imaging; the use of which is associated with increased hospital admissions and length of stay. The HS assay may therefore have significant health economic benefits.