Published May 17, 2013

Leicester, UK – It is essential that the relationships between diagnostic tests are understood in order to ensure the most effective diagnoses of diseases, as they rarely perform independently. To date, both clinical and economic evaluations of combinations of diagnostic tests have mostly assumed the tests to perform independently of one another. However, doing so will often over-estimate the performance of sequences of diagnostic tests. Researchers from the University of Leicester attempted to show how failure to allow for correlations between test performance may led to erroneous conclusions. By creating a framework for the evaluation of the diagnostic performance of sequences of tests and applying the framework to an economic evaluation of diagnostic strategies for Deep Vein Thrombosis, they determined that allowing for correlations between tests had considerable impact on the evaluation results. Professor Alex Sutton, researcher on the studies says, "As well as presenting a novel method in an under-researched area, this work also has important implications for those designing diagnostic evaluation studies in the future since it highlights the need for studies which evaluate multiple tests." The full studies: “Evaluating the Cost-Effectiveness of Diagnostic Tests in Combination: Is It Important to Allow for Performance Dependency?” and “Meta-Analysis of the Accuracy of Two Diagnostic Tests Used in Combination: Application to the Ddimer Test and the Wells Score for the Diagnosis of Deep Vein Thrombosis” are published in Value in Health.

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