Study objective: We sought to determine the sensitivity and specificity of the enzyme-linked immunosorbent assay (ELISA) D -dimer test in the diagnosis of pulmonary embolism (PE) in the adult emergency department population.
Methods: A search of MEDLINE, EMBASE, and bibliographies of previous systematic reviews was conducted, with no language restriction. Experts in the field of PE research were contacted to identify unpublished studies. Prospective investigations involving a predominately outpatient population suspected of PE that used ELISA D -dimer tests were included. Two authors extracted data independently and assessed study quality on the basis of the patient spectrum and reference standard. Consensus was reached by means of conference. The analysis was based on a summary receiver operating characteristic curve and pooled estimates for sensitivity and specificity by using a random-effects model.
Results: The search yielded 52 publications. No unpublished studies were found. Eleven studies met the inclusion criteria and provided a sample of 2,126 patients. The summary receiver operating characteristic curve analysis found significant heterogeneity among the 11 studies. Subgroup analysis of the 9 studies that used traditional ELISA D -dimer methods yielded the most valid pooled estimates, with a sensitivity of 0.94 (95% confidence interval [CI] 0.88 to 0.97) and a specificity of 0.45 (95% CI 0.36 to 0.55). Advanced age resulted in a lower specificity. A prolonged duration of symptoms decreased the sensitivity and specificity.
Conclusion: The ELISA D -dimer test is highly sensitive but nonspecific for the detection of PE in the clinical setting. This test might help clinicians safely rule out PE, especially in the face of low and low-to-moderate pretest probabilities.