Perspective Biological Markers for Autism Spectrum Disorders: Advantages of the Use of Receiver Operating Characteristic Curves in Evaluating Marker Sensitivity and Specificity

Figure 2

Receiver Operating Characteristic (ROC) curves showing sensitivity as a function of specificity in ASD and typically developing (control) children. (a) Urinary 8-isoprostane, (b) urinary hexanoyl-lysine adduct; (c) erythrocyte membrane omega 6/omega 3; (d) total monounsaturated fatty acids of the erythrocyte membrane; (e) fluidity of erythrocyte membrane (inner leaflet); (f) thiobarbituric acid reactive substances in erythrocyte membranes; and (g) combined ROC curve of the six parameters. Some parameter values increase in autistic children with respect to typically developing ones, while others decrease. ROC curve analysis of a combination of multiple parameters, albeit with opposite sign, increases both sensitivity and specificity. Values of these parameters, reported in [56], are shown in Table 7. ROC curve analyses were based on nonparametric methods. The confidence intervals of ROC curves were set at 95%.

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