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Questioning the use of an age‐adjusted D‐dimer threshold to exclude venous thromboembolism: analysis of individual patient data from two diagnostic studies
Author(s) -
Takach Lapner S.,
Julian J. A.,
Linkins L.A.,
Bates S. M.,
Kearon C.
Publication year - 2016
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/jth.13424
Subject(s) - venous thromboembolism , d dimer , medicine , thrombosis
Essentials It is unclear if raising the D‐dimer level to exclude venous thrombosis in older patients is valid. We compared this ‘age‐adjusted’ strategy with other ways of interpreting D‐dimer results. A non‐age adjusted increase, and using higher thresholds in younger patients, was just as accurate. Age‐adjustment of D‐dimer thresholds does not appear to be appropriate.Click to hear Prof. le Gal's presentation on controversies in venous thromboembolism diagnosisSummary Background Using a progressively higher D‐dimer level to exclude venous thromboembolism ( VTE ) with increasing age has been proposed but is not well validated. Objective To determine whether it is appropriate to use a progressively higher D‐dimer level to exclude VTE with increasing age. Patients/methods We analyzed clinical data and blood samples from 1649 patients with a first suspected deep vein thrombosis or pulmonary embolism. We compared the negative predictive values ( NPV s) for VTE , and the proportions of patients with a negative D‐dimer result, by using three D‐dimer interpretation strategies: a progressively higher D‐dimer threshold with increasing age (age‐adjusted strategy); the same higher D‐dimer threshold in all patients (mean D‐dimer strategy); and a progressively higher D‐dimer threshold with decreasing age (inverse age‐adjusted strategy). Results The NPV with the age‐adjusted strategy (99.6%; 95% confidence interval [ CI ] 99.0–99.9%) was not different from that with the mean D‐dimer strategy (99.7%; 95% CI 99.0–99.9%) or that with the inverse age‐adjusted strategy (99.8%; 95% CI 99.1–99.9%). The proportion of patients with a negative result with the age‐adjusted strategy (50.9%; 95% CI 48.5–53.4%) was not different from the proportion of patients with a negative result with the mean D‐dimer strategy (51.7%; 95% CI 49.3–54.1%) or with the inverse age‐adjusted strategy (49.5%; 95% CI 47.1–51.9%). Conclusions Our analysis does not support the use of a progressively higher D‐dimer level to exclude VTE with increasing age.