Diagnostic Accuracy of Triage Tests to Exclude Pulmonary Embolism

Summary

We performed a study in 403 prospectively included patients with suspected pulmonary embolism to compare the accuracy of a combination of the SimpliRED D-dimer assay and an intuitive clinical probability estimate with either one alone. Based on a conjoint diagnostic reference standard, including ventilation-perfusion lung scintigraphy and pulmonary angiography, the prevalence of pulmonary embolism was 31%. We demonstrated a high sensitivity (98%, 95% CI 95-100) and negative predictive value (94%, 95% CI 79-99) for the combination of the two tests. These figures were more favorable than for either test alone. The specificity of the combination was lower (11%, 95% CI 9-12) and consequently the proportion of patients in whom further diagnostic tests would have been avoided was only 8%. We conclude that the combined use of the SimpliRED test and the clinical probability estimate attains a higher sensitivity than either test alone. However, there remains a risk of false negatives and the exclusion efficiency is limited.

Key words

Pulmonary embolism - diagnosis - D-dimer - probability - estimate - triage

^** The investigators who participated in this study are listed in the appendix. The Dutch Health Insurance Council (project # D094-90) provided financial support for this study. HRB is an established investigator of the Dutch Heart Foundation.

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