Background. Strategies combining pretest clinical assessment and D-dimers measurement efficiently and safely rule out venous thromboembolism events (VTE) in low- and intermediate-risk patients. Objectives. As process of ageing is associated with altered concentrations of coagulation markers including an increase in D-dimers levels, we investigated whether D-dimers could reliably rule out VTE across age categories. Method. We prospectively assessed the test performance in 1,004 patients visiting the emergency department during the 6-month period with low or intermediate risk of VTE who also received additional diagnostic procedures. Results. 67 patients had VTE with D-dimers levels above the threshold, and 3 patients displayed D-dimers levels below the threshold. We observed that specificity of D-dimers test decreased in an age-dependent manner. However, sensitivity and negative predictive value remained at very high level in each age category including older patients. Conclusion. We conclude that, even though D-dimers level could provide numerous false positive results in elderly patients, its high sensitivity could reliably help physicians to exclude the diagnosis of VTE in every low- and intermediate-risk patient. 1. Introduction Venous thromboembolism events (VTE) are common disorders with major impact on clinical and economic outcomes [1]. As a result, diagnostic procedures have been developed to safely rule out the occurrence of VTE especially in the setting of emergency medicine. Several studies have underlined that D-dimers level below 500？ng/ml reliably excluded the diagnosis of VTE in patients previously identified by clinical pretest evaluation as low- or intermediate-risk patients [2–7]. The use of combined strategies including both clinical assessment and D-dimers measurement have been endorsed by most professional societies as they improve diagnosis with acceptable cost efficiency. As frequency of VTE increases with age, diagnostic strategies should be adjusted to elderly age groups of patients. However, interpretation of D-dimers level is altered in older patients, as ageing or underlying clinical conditions may activate coagulation. Consequently, performance of diagnostic strategies using D-dimers varies with age. In guidelines released in 2000, the European Society of Cardiology recommended the avoidance of D-dimers measurement in patients older than 80 years of age [8]. We therefore assessed the clinical value of D-dimers test across age categories in patients presenting in the emergency department with low- or intermediate-risk of VTE.
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