 The D-dimer test has been extensively evaluated in the exclusion of DVT, particularly in outpatients. ELISA D-dimer and second-generation latex agglutination immuno-turbidimetric tests have a remarkably high sensitivity and have been proved safe first-line tests in association with clinical probability to rule out DVT in outcome studies. The clinical usefulness of D-dimer is defined by the proportion of patients in whom DVT may be ruled out by a normal result and it is determined by the specificity. However, ELISA and second-generation latex agglutination immuno-turbidimetric tests tests have a quite limited overall specificity of around 35 to 40.3 Therefore, many investigators tried to increase the D-dimer thresholds in particular in elderly patients to increase the rate of patients in whom the diagnosis could be excluded by this easy and inexpensive test. Several studies have shown that D-dimer levels increase with age, which turns in a decreased specificity of the D-dimer test at the usual threshold in the elderly, and thus to a less useful test to exclude both DVT and pulmonary embolism PE in older patients. For example, ELISA D-dimer is able to rule out PE in 60 of patients aged less than 40 years, but in only 5 of patients above the age of 80. In this study, raising the cutoff value to various points between 600 microgL and 1000 microgL increased specificity, but this came at the cost of safety with more false negative test results. In this analysis, however, no stratification was made for clinical probability and the sample was small. 