Instructions: Enter parameters in the red cells. Answer will appear in the blue cells.

This uses the general definition for the likelihood ratio of test result R, LR(R), as the probability of the test result in disease, P(R|D+), divided by the probability of the test result in non-disease, P(R|D-).

Confidence Level (e.g., 0.95)

D+D-
Total number
Total with result R
P(R|D+) or P(R|D-)0.7500.250

LR(R)Confidence Interval
3.0003.000 -- 3.000

Reference: Simel DL, Samsa GP, Matchar DB. J Clin Epidemiol. 44(8):763-70.

Z 0.00
ln(LR) 1.099
Variance of ln(LR) 0.033
SD of ln(LR) 0.183
ln(Lower Bound of CI) 1.099
ln(Upper Bound of CI) 1.099
Lower Bound of CI 3.000
Upper Bound of CI 3.000