User's guide to the surgical literature: How to use an article about a diagnostic test

The primary issues to consider in determining the validity of a diagnostic test study are how the authors assembled the patients and whether they used an appropriate reference standard for all patients to determine whether the patients did or did not have the target condition. Likelihood ratios are key to the interpretation of diagnostic tests as they link estimates of pretest probability to posttest probability. Sensitivity is the property of the test that describes the proportion of individuals with the disorder in whom the test result is positive. Specificity is the property of the test that describes the proportion of individuals without the disorder in whom the test result is negative.