Figure 2.

Receiver operator characteristic (ROC) curves for the classification of adult hypertension by childhood levels of systolic blood pressure (SBP), fourth Korotoff phase (K4), and fifth Korotkoff phase (K5). The 3 curves show the sensitivity (y-axis) and specificity (x-axis) of each blood pressure measure at all possible cut points, and a better classifier would have a curve that is shifted upwards (higher sensitivity at the same specificity). Both SBP and K4 were more strongly (P < 0.001) associated with adult hypertension than was K5. The dashed line, which has a slope of −1, indicates the curve that would be expected if there was no relation of childhood blood pressure levels to adult hypertension.