Ekstra Güvenlik Eşik Değeri ile Karar Vermede Eğri Altında Kalan Alan İçin Yeni Bir Bakış Açısı: Bir Simülasyon Çalışması

Abstract

Objective: In studies conducted to detect a disease, making a false negative decision in cases such as detecting a deadly disease (Case I), or making a false positive decision in cases where diseases with high treatment costs (Case II) can lead to dangerous results. In this study, a new definition of the area under the curve (AUC) is proposed using a safety threshold value t for the diagnostic test to provide flexible decisions in critical cases. The alternative cut-off point for test diagnosis is evaluated by a simulation study in terms of sensitivity/specificity and relative efficiency. Materials and Methods: A simulation study was performed using different AUC values to obtain the cut-off point c shifted towards c-t for Case I and c+t for Case II. The normal distribution is used for the diseased (X) and non-diseased (Y) data. When obtaining the shift amount t, the gamma probability, which is the desired percentage of increase or decrease in the sensitivity/specificity value, is taken into account. Results: The results of our study showed that the relative efficiency is not significantly affected by working with the safety threshold t value when the test is less accurate and has a low AUC value. Conclusion: In this study, alternative cut-off points are obtained using the shift amount t determined by a predefined gamma probability. It is suggested that in critical situations, using the extra safety threshold t, determining the actual disease margin and safety standards for subjects can provide a more tolerant decision, especially in tests with low discrimination power.