Nomogram for using Likelihood Ratios (LRs) to convert pre-test probabilities into post-test probabilities for diagnostic test results with a known LR.
Drag the blue arrows to the values you have for your patient's pre-test probability (%) and the test result's LR, and read off the post test probability from the red arrow on the right. |
Please note that you will need the Shockwave plug-in
to view this interactive image. |
Note that by entering the data from a good quality study of a diagnostic test, you can use this interactive nomogram (e.g. by varying the pre-test probability) to begin answering the question "How different would my patient have to be from the patients in the study before this evidence was no use to me?"