Hello! :)
The likelihood ratio of a positive test result (LR+) is sensitivity divided by 1- specificity.
How I remember the formulae for LR+ and LR-
1) Remembering the numerator and denominator: N / P - You can remember this as N comes before P. I remember this because my name starts with N. So it is seNsitivity / sPecificity.
2) Remembering where the (1 - S) is: The (1-S) is wherever the N or P is. likelihood ratio Negative will have 1 - seNsitivity. likelihood ratio Positive will have 1 - sPecificity.
In summary:
LR+ = Sensitivity / 1 - Specificity
LR - = 1 - Sensitivity / Specificity
That's all!
-IkaN
Thanks a lot
ReplyDeletedo we need to know the pretest/posttest probability stuff as well?
ReplyDelete