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Use of different d ‐dimer levels to exclude venous thromboembolism depending on clinical pretest probability
Author(s) -
Linkins L.A.,
Bates S. M.,
Ginsberg J. S.,
Kearon C.
Publication year - 2004
Publication title -
journal of thrombosis and haemostasis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.947
H-Index - 178
eISSN - 1538-7836
pISSN - 1538-7933
DOI - 10.1111/j.1538-7836.2004.00824.x
Subject(s) - d dimer , medicine , pre and post test probability , venous thromboembolism , cut point , statistics , mathematics , thrombosis
Summary. Currently, the same d ‐dimer cut‐off point is used to define a positive result for all patients with suspected venous thromboembolism, regardless of their pretest probability. However, use of a relatively high d ‐dimer cut‐off point (lower sensitivity) for those with a low clinical pretest probability, and a low d ‐dimer cut‐off point (higher sensitivity) for those with a high clinical pretest probability, may be preferable. To determine if using three different d ‐dimer cut‐off points according to low, moderate or high clinical pretest probability has greater utility for exclusion of venous thromboembolism than using the same single d ‐dimer cut‐off point in all patients. Data from a previously published study of 571 patients was used to identify the highest d ‐dimer cut‐off point with a negative predictive value of at least 98% for the subgroup of patients with low and high pretest probability. The d ‐dimer cut‐off point for those with moderate clinical pretest probability remained unchanged [0.5 fibrinogen equivalent units (FEU) µg mL −1 ]. Accuracy of d ‐dimer testing for venous thromboembolism using three cut‐off points vs. one cut‐off point was than determined. d ‐dimer cut‐off points of 0.2 and 2.1 FEU µg mL −1 were selected for the high and low pretest probability groups, respectively. When three pretest probability‐specific cut‐off points were used instead of the previously determined single d ‐dimer cut‐off point (0.5 FEU µg mL −1 ), sensitivity and negative predictive value were unchanged (95 and 98%, respectively), but specificity increased from 44.7 to 60.4% ( P < 0.001). This resulted in exclusion of venous thromboembolism in 80 additional patients. Use of three pretest probability‐specific d ‐dimer cut‐off points rather than a single d ‐dimer cut‐off point for all patients, has the potential to increase the utility of d ‐dimer testing for the diagnosis of venous thromboembolism.