A comparison of two diagnostic performance measures Signal-to-noise ratio versus partial area under receiver operating characteristic curve

Abstract

Purpose – This paper aims to compare two diagnostic performance measures, i.e. signal-to-noise ratio (S/N ratio) and partial area under receiver operating characteristic curves (pAUC). It proposes the use of S/N ratio rather than pAUC for establishing optimal cut-off point for diagnostic biomarkers. Design/methodology/approach – This paper discusses the properties, uses, advantages and shortcomings of the two performance measures, namely the partial area under receiver operating characteristic curve (pAUC) and Taguchi’s signal-to-noise (S/N) ratio. The benefits of S/N ratio have been illustrated in a sample of four biomarkers, each having five cut-off points. The S/N ratio is compared to the pAUC index. The SAS software is employed to calculate pAUC and AUC. Findings – This paper shows that S/N ratio can be used as a measure of diagnostic accuracy. The cut-off point with the highest S/N ratio is the optimal cut-off point for the biomarker. The proposed method has the advantages of being easier, more practical and less costly than that of pAUC. Practical implications – This paper includes implications for the development of a more practical, equally powerful and less costly means of measuring clinical accuracy thereby reducing the costs and risks resulting from wrong selection of cut-off point can be decreased. Originality/value – This paper supports suggestions in the recent literature to replace pAUC with a new, more meaningful index.