D-Dimer Testing for Deep Venous Thrombosis: A Metaanalysis

Abstract

Background: The use of D-dimer assays as a rule-out test for deep venous thrombosis (DVT) is controversial.To clarify this issue we performed a systematic review of the relevant literature. Methods: We identified eligible studies, using MED-LINE entries from February 1995 through October 2003, supplemented by a review of bibliographies of relevant articles. Studies reporting accuracy evaluations comparing D-dimer test results with lower extremity ultrasound or venography in symptomatic patients with suspected acute DVT were selected for review. Two reviewers critically appraised each study independently according to previously established methodologic standards for diagnostic test research. Those studies judged to be of highest quality were designated Level 1. Results: The 23 Level 1 studies reported data on 21 different D-dimer assays. There was wide variation in assay sensitivity, specificity, and negative predictive values, and major differences in methodology of reviewed studies. A multivariate analysis of assay performance, controlling for sample size, DVT prevalence, reference standard, and patient mix, found few differences among the assays in effect on test performance as measured by diagnostic odds ratio. Increasing prevalence of DVT was associated with poorer test performance (P ‫؍‬ 0.01), whereas the choice of venography as the reference standard was associated with better test performance (P <0.005). Conclusions: Explanations for the wide variation in assay performance include differences in biochemical and technical characteristics of the assays, heterogeneity and small size of patient groups, and bias introduced by choice of reference standards. Assay sensitivity and negative predictive value were frequently <90%, un-

Different cut-off values of quantitative D-dimer methods to predict the risk of venous thromboembolism recurrence: a post-hoc analysis of the PROLONG study

“…[14][15][16][17] Despite the widespread use of Ddimer measurement, clinicians are puzzled by the high variability in numerical results produced by the different methods now available. Indeed, one of the main problems of D-dimer assays is that it is not currently possible to standardize results from different assays, [18][19][20][21][22][23] making it difficult to extrapolate results from one setting to another.…”

Diagnostic Accuracy and User-Friendliness of 5 Point-of-Care D-Dimer Tests for the Exclusion of Deep Vein Thrombosis

“…More than 75% of the patients in whom deep vein thrombosis (DVT) 3 is suspected and who are referred for objective testing-commonly performed with legcompression ultrasonography-do not have DVT (1,2 ). D-dimer testing for DVT has been introduced to improve the diagnostic process and, in particular, to reduce the number of unnecessary referrals for leg-compression ultrasonography.…”

“…Concentrations of D-dimer are increased in patients with DVT, but may also be increased in other conditions such as cancer, infections, pregnancy, and recent surgery. Hence, D-dimer tests are typically used as rule-out tests (3,4 ). Although D-dimer testing is readily available to many hospital physicians within their central laboratories, this is often not the case for primary care physicians.…”

Deep Vein Thrombosis in a Young Marathon Athlete

“…16 It has been well established that clinical signs and symptoms are unreliable in identifying a DVT. 1,4,5,7,13,14,17 The classic Homan's sign is commonly used; however, because of its high false-positive and false-negative rates, results are frequently misleading, 8,12 making this test of little benefit. In contrast, clinical prediction rules (CPRs), such as those described by Wells et al, [17][18][19][20][21] known as the Wells score, have proven much more reliable and clinically meaningful in the outpatient population.…”

“…1 However, a metaanalysis that included 23 diagnostic accuracy studies of the D-dimer test reported a wide range of sensitivity values (0.51-1.00), with more than 33% of the studies reporting sensitivity values less than 0.90. 8 Due to the very serious potential complications of misdiagnosing an existing DVT, a negative D-dimer must not be considered a definitive test, particularly if the pretest probability of a DVT is high or moderately high. In this case, it is important to realize that, had the D-dimer test been negative, a more definitive study, such as compression ultrasound, would have been requested due to the high pretest probability of DVT.…”