The use of D-dimer to exclude VTE in both of these populations is also somewhat problematic. Both populations have elevated D-dimer levels at baseline, and, thus, the clinical utility (eg, specificity, number of patients tested to rule out VTE on just one patient) is much lower. It should be stressed, however, that the sensitivity remains high in these patients. We would like to avoid imaging studies in both of these populations (because of either the risk that the contrast dye could worsen renal function or radiation risk to the fetus). Therefore, if we can exclude VTE in even a small number of patients, it would still be helpful.3 In addition, recent research has focused on establishing new normal ranges for special populations, including patients who are elderly or pregnant.4,5 Use of these new cutoff values in treatment studies may increase the diagnostic utility of the D-dimer in these groups in the future.