Physical Examination of the Liver

The utility of the test results on formulating a posttest probability where the pretest probability of hepatomegaly is 50% (high pretest probability), 20% (moderate pretest probability), or 2% (low pretest probability). All red lines represent the application of the positive likelihood ratio to the pretest odds, changing posttest probabilities to 80%, 45%, and 7.5%, respectively. Using the same approach, application of the negative likelihood ratio to the pretest probabilities (black lines) changes posttest probabilities to 30%, 10%, and less than 1%, respectively.