Brief Reports: PDF OnlySensitivity and Specificity-like Measures of the Validity of a Diagnostic Test That Are Corrected for Chance AgreementCoughlin, Steven S.1,2; Pickle, Linda W.3Author Information 1From the Department of Medicine, Divisions of Medical Oncology and Cardiology, Georgetown University School of Medicine, Washington, DC 2From the Vincent T. Lombardi Cancer Research Center, Georgetown University Medical Center, Washington, DC 3From the Statistical Technology Staff, Office of Research Methodology, National Center For Health Statistics, Hyattsville, MD Epidemiology: March 1992 - Volume 3 - Issue 2 - p 178-181 Free Abstract Chance agreement may account for a sizeable proportion of the specificity of a screening test when the disease prevalence is low. Conversely, the observed sensitivity may be largely accounted for by chance agreement when the prevalence of disease is high. We derive descriptive statistics that are analogous to sensitivity and specificity and corrected for the agreement expected by chance. These coefficients of validity are shown to be dependent on the true prevalence of disease, as well as sensitivity and specificity. (Epidemiology 1992;3:178–181) © Lippincott-Raven Publishers.