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Likelihood Ratio nomogram

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.
If you do not have Shockwave installed, you will be presented with the opportunity to download it.
We recommend you do so, as this adds functionality to your browser.


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?"