Interpreting Diagnostic Tests
Thomas G. Tape, MD
University of Nebraska Medical Center
Basic Concepts
Introduction
Definition of sensitivity, specificity, and predictive value
How to evaluate a 2 by 2 table
Practice working with 2 by 2 tables
Understanding and Using Likelihood Ratios
Introduction
Likelihood ratios for tests with only two possible results
Computing likelihood ratios from sensitivity and specificity
Likelihood ratios for tests with more than two possible results
Using likelihood ratios to analyze a series of tests
ROC Curves
Introduction to ROC Curves
Plotting and interpreting an ROC curve
The area under an ROC curve
Measuring the effect size of an intervention
Relative risk reduction, absolute risk reduction and the Number needed to treat