A Hybrid Indicator of Youden Index and Taguchi Loss Function to Determine the Diagnostic Efficiency

Pei-Chun Wu, Ful-Chiang Wu


Taguchi's robust design aims to reduce the impact of noise on the product or process quality and leads to greater customer satisfaction and higher operational performance. The objective of robust design is to minimize the total quality loss in products or processes. A diagnostic test is a medical test that is applied to a patient in order to determine the presence of a specific disease, where early and accurate diagnosis can decrease morbidity and mortality rates of disease. The application of a diagnostic test in the assessment of a disease may lead to errors, and therefore the accuracy of a diagnostic test is measured in terms of two probabilities: sensitivity and specificity. The problem of two error probabilities in diagnostic tests can be viewed as a digital dynamic system in Taguchi robust design. This paper presents a hybrid index to capture the performance of a diagnostic test based on Youden's index and Taguchi's quality loss function. The loss model of diagnostic tests is proposed due to different loss coefficients between false negative and false positive. The Youden_Taguchi index can be used as a criterion to discriminate non-diseased from diseased individuals for minimizing the total loss of misdiagnoses.


Diagnostic test, Sensitivity and specificity, Taguchi robust design, Quality loss function, Youden_Taguchi index


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