Instructor's Note: Using Test Information II

This instructor's note supports the teaching pack on Using Test Information II, in which students are introduced to tests with continuous or categorical results, and calculate the sensitivity and specificity conditional on different ‘cutoff points’ or 'positivity criterion'. They are introduced to ROC curves and explore the implications of operating at different parts of the curve for any single test. They calculate the optimal positivity criterion given information on the prior, the test performance, and the relative consequences of true positives, false negatives, and false positives. In addition to the instructor's note, materials include videos, companion slides, a glossary, an annotated bibliography, and sample exercises.

Learning Objectives

1. Calculate the sensitivity and specificity conditional on different ‘cutoff points’ (i.e., positivity criterion) for a test with continuous results, and plot an ROC curve.
2. Describe the implications of operating at different parts of the ROC curve for any single test - explain the implications of ‘strict’ and ‘lenient’ cutoffs.
3. Calculate the optimal positivity criterion for a test given information on the prior probability, the test performance, and the relative consequences of true positives, true negatives, false negatives, and false positives.

Teaching Pack Materials

• Instructor's Note: Using Test Information II
• Videos, Part 1: Introducing Continuous Test Results (3 videos)
• Videos, Part 2: Optimal Positivity Criterion (4 videos)
• Companion Slides to Videos, Part 1: Continuous Test Results
• Companion Slides to Videos, Part 2: Optimal Positivity Criterion
• Glossary: Using Test Information II
• Bibliography: Using Test Information II
• Sample Exercises: Using Test Information II

This teaching pack was developed by Sue J. Goldie at the Center for Health Decision Science, Harvard T.H. Chan School of Public Health. The multimedia components were developed as part of a series of pilots in the CHDS Media Hub, led by Jake Waxman, where media-based pedagogy experiments contribute to new ways of thinking about short form content.