Background: The reported diagnostic accuracy of the D-dimer test for exclusion of deep vein thrombosis (DVT) and pulmonary embolism (PE) varies. It is unknown to what extent this is due to differences in study design or patient groups, or to genuine differences between D-dimer assays.
Methods: Studies evaluating the diagnostic accuracy of the D-dimer test in the diagnosis of venous thromboembolism were systematically searched for in the MEDLINE and EMBASE databases up to March 2005. Reference lists of all included studies and of reviews related to the topic of the present meta-analysis were manually searched for other additional potentially eligible studies. Two reviewers independently extracted study characteristics using standardized forms.
Results: In total, 217 D-dimer test evaluations for DVT and 111 for PE were analyzed. Several study design characteristics were associated with systematic differences in diagnostic accuracy. After adjustment for these features, the sensitivities of the D-dimer enzyme-linked immunofluorescence assay (ELFA) (DVT 96%; PE 97%), microplate enzyme-linked immunosorbent assay (ELISA) (DVT 94%; PE 95%), and latex quantitative assay (DVT 93%; PE 95%) were superior to those of the whole-blood D-dimer assay (DVT 83%; PE 87%), latex semiquantitative assay (DVT 85%; PE 88%) and latex qualitative assay (DVT 69%; PE 75%). The latex qualitative and whole-blood D-dimer assays had the highest specificities (DVT 99%, 71%; PE 99%, 69%).
Conclusions: Compared to other D-dimer assays, the ELFA, microplate ELISA and latex quantitative assays have higher sensitivity but lower specificity, resulting in a more confident exclusion of the disease at the expense of more additional imaging testing. These conclusions are based on the most up-to-date and extensive systematic review of the topic area, including 184 articles, with 328 D-dimer test evaluations.