DEFINITION:
the total number of cases or events, such as illness, in a given population at a designated time, often called point prevalence which also provides an estimate of the probability (risk) that an individual will experience that event at a point in time | |
prevalence is a proportion not a rate, and is often expressed as a % |
FORMULA for PREVALENCE:
Number
of existing cases of a event , illness, or disease (at a
point in time)
_____________________________________________________________
Total population
*Frequently used is the total % of children <-2 SD WAZ (underweight prevalence). The percent of people unemployed or not educated, or households without a latrine are also prevalences, but not usually called that.
** In the economics literature, incidence (number of new cases/ time) is often confused or used interchangeably with prevalence. Therefore, often reported is the ‘incidence of poverty’ or ‘incidence of undernourished’. In epidemiological (and PANDA) terms, it is the percent at one time that is the prevalence. Why economists decided to change the terms is a mystery, at least to us.