title: Comparing diagnostic tests: a simple graphic using likelihood ratios.
abstract: The diagnostic abilities of two or more diagnostic tests are traditionally compared by their respective sensitivities and specificities, either separately or using a summary of them such as Youden's index. Several authors have argued that the likelihood ratios provide a more appropriate, if in practice a less intuitive, comparison. We present a simple graphic which incorporates all these measures and admits easily interpreted comparison of two or more diagnostic tests. We show, using likelihood ratios and this graphic, that a test can be superior to a competitor in terms of predictive values while having either sensitivity or specificity smaller. A decision theoretic basis for the interpretation of the graph is given by relating it to the tent graph of Hilden and Glasziou (Statistics in Medicine, 1996). Finally, a brief example comparing two serodiagnostic tests for Lyme disease is presented. Published in 2000 by John Wiley & Sons, Ltd.
authors.affiliation: Centers for Disease Control and Prevention, National Center for Infectious Diseases, Division of Vector-Borne Infectious Diseases, P. O. Box 2087, Fort Collins, Colorado 80522-2087, USA. bkb5@cdc.gov
authors.forename: B J
authors.initials: BJ
authors.lastname: Biggerstaff
mesh_terms: D003955:Diagnostic Tests, Routine; D005189:False Positive Reactions; D006801:Humans; D016013:Likelihood Functions; D008193:Lyme Disease / Q000175:diagnosis; D015233:Models, Statistical; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012698:Serologic Tests