What is a C-statistic?

What is a C-statistic?

What is a C-Statistic? The concordance statistic is equal to the area under a ROC curve. In clinical studies, the C-statistic gives the probability a randomly selected patient who experienced an event (e.g. a disease or condition) had a higher risk score than a patient who had not experienced the event.

How do you find C-statistic?

The c-statistic is equal to the AUC (area under the curve), and can also be calculated by taking all possible pairs of individuals consisting of one individual who experienced a positive outcome and one individual who experienced a negative outcome.

What does AUC measure?

AUC stands for “Area under the ROC Curve.” That is, AUC measures the entire two-dimensional area underneath the entire ROC curve (think integral calculus) from (0,0) to (1,1). Figure 5. AUC (Area under the ROC Curve). AUC provides an aggregate measure of performance across all possible classification thresholds.

Is AUC good for Imbalanced data?

ROC AUC and Precision-Recall AUC provide scores that summarize the curves and can be used to compare classifiers. ROC Curves and ROC AUC can be optimistic on severely imbalanced classification problems with few samples of the minority class.

What is a high C-index?

So the c-index can not be interpreted as the risk of a subject. High values mean that your model predicts higher probabilities of survival for higher observed survival times. Hope this helps!

What is C in conditional probability?

P(A and B) = P(A)P(B|A). From this definition, the conditional probability P(B|A) is easily obtained by dividing by P(A): Note: This expression is only valid when P(A) is greater than 0.

What does C denote in mathematics?

Usage. The capital Latin letter C is used in mathematics as a variable. For example, it appears in geometric formulas as a variable representing the circumference of a circle. It also is used to represent the set of complex numbers displayed using a “double-struck” typeface.