For centuries, knowledge about the cause of disease and how to treat or prevent it was limited by the fact that it was based almost entirely on anecdotal evidence. Significant advances occurred when the strategy for studying disease shifted to looking at groups of people and using a numeric approach to make critical comparisons.

Learning Objectives

After successfully completing this section, the student will be able to:

 crude rates

 category-specific rates (e.g. gender or race)

 age-specific rates

 morbidity rate

 mortality rate

 case-fatality rate

 attack rate

 live birth rate

 infant mortality rate

 autopsy rate