What is a good Youden index?

The cut-off point for having an acceptable Youden index is 50%. Any value below 50% denote an overall lack of the diagnostic test to detect either disease or health.

What is an acceptable ROC curve?

AREA UNDER THE ROC CURVE In general, an AUC of 0.5 suggests no discrimination (i.e., ability to diagnose patients with and without the disease or condition based on the test), 0.7 to 0.8 is considered acceptable, 0.8 to 0.9 is considered excellent, and more than 0.9 is considered outstanding.

How does SPSS calculate Youden index?

COMPUTE Specificity = 1 – @1Specificity. COMPUTE Youden = Sensitivity – @1Specificity.

What is optimal cut-off point?

It defines the optimal cut-point value as the point minimizing the summation of absolute values of the differences between AUC and sensitivity and AUC and specificity provided that the difference between sensitivity and specificity is minimum.

What is the J value in statistics?

Youden’s J is the likelihood of a positive test result in subjects with the condition versus those without the condition. It is also the probability of an informed decision (as opposed to a random guess).

How do you interpret ROC AUC scores?

AUC represents the probability that a random positive (green) example is positioned to the right of a random negative (red) example. AUC ranges in value from 0 to 1. A model whose predictions are 100% wrong has an AUC of 0.0; one whose predictions are 100% correct has an AUC of 1.0.

What does a good ROC curve look like?

Generally, tests are categorized based on the area under the ROC curve. The closer an ROC curve is to the upper left corner, the more efficient is the test. In FIG. XIII test A is superior to test B because at all cut-offs the true positive rate is higher and the false positive rate is lower than for test B.

How do you choose cut-off ROC curve?

The closer a curve to this point, the better is a test. No surprise, another common criterion for choosing the most appropriate cut-off value is selecting the point on the ROC curve with the minimum distance from the left-upper corner of the unit square (8, 15, 16).

What is cutoff in ROC curve?

Empirical ROC Curve That is, each point on the ROC curve represents a different cutoff value. The points are connected to form the curve. Cutoff values that result in low false-positive rates tend to result low true-positive rates as well. As the true-positive rate increases, the false positive rate increases.