Stats Flashcards
1
Q
Formula for Sensitivity
A
proportion of people with the disease who test positive
(TP / TP + FN)
2
Q
Formula for Specificity
A
proportion of people without the disease who test negative
(TN/ TN + FP)
3
Q
Formula for PPV?
A
TP/ TP + FP
4
Q
Formula for NPV?
A
TN/ TN + FN
5
Q
How to convert from a pre-test probability to post test probability given a likelihood ratio
A
6
Q
What are ROC curves
A
Receiver Operating Characteristic curves
Compare sensitivity vs Specificity (technically 1- specificity) at different points.
Best to be in the top left corner.
Compare them for different test by comparing the area under the curve.
7
Q
What is Standard error
A
standard deviation of the sampling distribution`
