[Cost-effectiveness analysis of different imaging for the diagnosis of acute pulmonary embolism]

The optimal diagnostic test for detecting acute pulmonary embolism (APE) is still under discussion. The ventilation /perfusion scanning has been the preferred examination for several decades, but with the development of new tests the diagnostic possibilities have increased. It is necessary to evaluate them from the cost-effectiveness perspective. The goal of this study was to evaluate several methods of imaging diagnosis so as to determine the most cost-effective for detecting APE.

Cost-effectiveness (CE) analysis using a decision tree to model various diagnostic test (V/Q lung scan, spiral CT, angiography by MDCT, MRI and conventional arteriography). Sensitivity and specificity values, and positive and negative predictive values of diagnostic tests were calculated. Expected outcome: "new APE case detected." The direct costs were evaluated in eurosos (euros), including the secondary complications of diagnostic methods. To assess the robustness of the findings, a one way sensitivity analysis was performed.

The most cost-effective diagnostic test was angiography by MDCT. No diagnostic test were eliminated by extended dominance. The crude rate of CE for MDCT was 486 euros per case of APE detected. The marginal cost between spiral CT and V / Q lung scan was euros 103 for 8 cases of APE detected additionally, while the marginal cost between MDCT and spiral CT was 229 euros to detect an additional case of APE.

The most cost-effective diagnostic test was the MDCT; this finding showed to be robust in relationship to sensitivity, specificity and costs changes. However, the incremental C-E analysis showed that MDCT was capable to detect only one additional case of APE than spiral CT, with an incremental cost of 229 euros. When peripheral branches are affected, high negative predictive value of the MDCT justify its conduct.