Confidence Intervals for Sensitivity & Specificity

Question 1

how equate the CI o sensitivity and specificity?

Answer 1

look at the formulas

Question 2

how does scientist came up with the cut-off point?

Answer 2

1. inding the speificity and sensivity at diferent concentrations, or watever is being measurend.
2. Forming a Receiver Operating Characteristic” curve (ROC curve)
3. looking or the left-most top-corner point, greater AUC
4. find Distance-squared = (1 – Sensitivity)^2 + (1 – Specificity)^2
5. select the lowest one

Question 3

what is a Receiver Operating Characteristic” curve (ROC curve)?

Answer 3

a graph that plots 1-specificity vs sensivity

x=1-specificity

ideal test: (1 – Specificity, Sensitivity) = (0, 1).