Talk:Youden's J statistic

Comment on "The index gives equal weight to false positive and false negative values, so all tests with the same value of the index give the same proportion of total misclassified results" in the first paragraph. This is only true if the number of "patient" is equal to the number of "control". In the case of desiquilibrium, the lower category has more weight. For instance, with 15 patients and 5 controls, the patient weight is 1/15 and the control is 1/3. In this situation, the best Youden's index will minimize the misclassification of the controls. 195.220.100.11 (talk) 14:10, 20 February 2015 (UTC)

Deltap'
What does deltap or deltap' have to do with Youden's index? The Perruchet paper does not mention Youden's index, nor does it refer to sensitivity and specificity in any way that would make the equivalence clear, so it does not appear a satisfactory reference for this. I suggest taking out the reference to deltap and informedness, unless someone comes up with a more satisfactory linkage. Kognos (talk) 15:36, 12 August 2014 (UTC)

"Its value ranges from 0 through 1" It is false, J is between -1 and 1, for perfectly wrong classifier TP and TN are 0, so J = -1 — Preceding unsigned comment added by 165.225.84.161 (talk) 10:46, 16 July 2019 (UTC)