CDISC-Gloss – A proportion calculated as the number of individuals who develop the disease during a period of time divided by the number of persons at risk. [After AMA Style Guide, 10th Edition; After Principles of Epidemiology in Public Health Practice, Third Edition. An Introduction to Applied Epidemiology and Biostatistics, Lesson 3: Measures of Risk, CDC 2012] See also morbidity rate, morbidity, mortality, incidence, prevalence.