I hope somebody could help me with a quick question. I am reading a medical paper where the researchers did a very bad job at reporting the methodology. They are checking the predictive power of a leg raising test in diagnosing a hernia. It is a dichotomous variable - patient says yes or no.
They report predictive values of the tests like this: 0.83 with confidence interval [0.67,0.92]. How is it possible that 0.83, the reported value, is not in the center of the CI. Normally I would think that the found value of 0.83 will be used as a center to which Z*sigma/sqrt(n) is added/subtracted.
If anyone could help, thank you very much! Here's the article if you wanna take a look: https://www.researchgate.net/publication/5460289_The_Sensitivity_and_Specificity_of_the_Slump_and_the_Straight_Leg_Raising_Tests_in_Patients_With_Lumbar_Disc_Herniation