Definition

Incidence is the number of new cases of a condition, symptom, death, or injury that arise during a specific period of time, such as a year. It is often expressed as a percentage of a population (e.g., 25% of American residents were diagnosed with the flu in 2002).

Incidence conveys the likelihood that an individual in that population will be affected by the condition.


Review Date:7/29/2005
Reviewed By: Paul B. Tabereaux, M.D., M.P.H., Division of Cardiovascular Diseases, Department of Internal Medicine, University of Alabama School of Medicine, Birmingham, AL. Review provided by VeriMed Healthcare Network.