Pub. date: 2008 | Online Pub. Date: November 27, 2007 | DOI: 10.4135/9781412953948 | Print ISBN: 9781412928168 | Online ISBN: 9781412953948| Publisher:SAGE Publications, Inc.About this encyclopedia
Rongwei (Rochelle) Fu
The hazard rate is a measure used to quantify the relative frequency of disease occurrence in a population and plays an important role in descriptive and etiologic investigations. The definition of hazard rate is given as the instantaneous change in the occurrence of new cases per unit change of time at a particular time point, relative to the size of the disease-free population at that particular point in time. It is a theoretical limit of the rate as the time interval goes to zero and could seldom be obtained in reality. Instead, an average rate for a given period is usually estimated and used in epidemiology, analogous to incidence ...