PMean: The Likelihood Ratio Slide Rule poster submission

I submitted a poster to the 2015 UMKC Faculty Research Symposium (described at the UMKC Office of Research Support website). It’s a chance to show off some of the work I did a while back and to look for collaborators among other UMKC faculty for future research projects.

The Likelihood Ratio Slide Rule.

The Likelihood Ratio Slide Rule is a pocket sized device that allows you to calculate the post test probability of disease after a positive or negative result on a medical diagnostic test. It is loosely based on the Fagan Nomogram (Fagan TJ. NEJM 1975, Jul 31; 293(5): 257). This poster will show practical uses of the slide rule, including estimating positive and negative predictive values for varying disease prevalence levels and calculating a range of pre-test probabilities for which a diagnostic test is unnecessary. You can pick up one of these slide rules at the poster session while supplies last.

This slide rule was originally developed in 2002 and described on my website at

In future blog entries, I will update and revise that page and share more details about this slide rule and how it works.