A total of 130 patients were screened for Disc prolapse by CT scan and confirmation of the disease was made by discectomy operation. Out of 56 patient who screened positive in CT-scan, 46 were confirmed for disease in operation. Rest 74 patient who were screened negative in CT scan, only 40 patient were confirmed negative for the disease in operation. Calculate the Positive and Negative likelihood ratio.
+ - Total + a (46) b (10) 56 - c (34) d (40) 74 Sensitivity = x 100 = 46/80 x 100 = 0.575 Specificity = x 100 = 40/50 x100 = 0.80 LR+ = = 0.575/ (1-0.80) = 2.875 LR- = = 1-0.575 / 0.80 = 0.531
2.875 and 0.531
6.07 and 1.12
1.12 and 6.07
0.531 and 2.875
Sensitivity, Specificity, PPV, NPV