Diagostic tests: Moving beyond sensitivity and specificity: using likelihood ratios to help interpret diagnostic tests

part 3: positive and negative likelihood ratios of diagnostic tests

in the previous two parts of educational manuscript series in emergency, we explained some screening characteristics of diagnostic tests including accuracy, sensitivity, specificity, and positive and negative predictive values. in the 3rd  part we aimed to explain positive and negative likelihood ratio (lr) as one of the most reliable performance measures of a diagnostic test. to better underst...

Comparing Rasch analyses probability estimates to sensitivity, specificity and likelihood ratios when examining the utility of medical diagnostic tests.

INTRODUCTION Medical diagnostic tests are evaluated based on measures of sensitivity (Sn), specificity (Sp), and likelihood ratios (LR). These procedures are limited in the event of a biased gold standard or missing data. Interpretations of these measures are frequently inappropriate. PURPOSE The Rasch measurement model (RMM) was examined as a method to provide evidence of diagnostic test uti...

Understanding diagnostic tests 1: sensitivity, specificity and predictive values.

UNLABELLED The usefulness of diagnostic tests, that is their ability to detect a person with disease or exclude a person without disease, is usually described by terms such as sensitivity, specificity, positive predictive value and negative predictive value. In this article, the first of the series, a simple, practical explanation of these concepts is provided and their use and misuse discussed...

Ophthalmic statistics note 5: diagnostic tests—sensitivity and specificity

This is the fifth statistics note produced by the Ophthalmic Statistics Group (OSG) which is designed to be a simple guide to ophthalmic researchers on a statistical issue with an applied ophthalmic example. The OSG is a collaborative group of statisticians who have come together with a desire to raise the statistical standards of ophthalmic researcher by increasing statistical awareness of com...

Sensitivity, specificity, predictive values, and likelihood ratios.