##### Asked by: Pureza Traina

asked in category: General Last Updated: 31st May, 2020# Is attack rate a percentage?

**attack rate**is the biostatistical measure of frequency of morbidity, or

**speed**of spread, in an at risk population. The

**rate**is arrived at by taking the number of new cases in the population at risk and dividing by the number of persons at risk in the population.

Likewise, how do you calculate attack rate?

The **attack rate** is calculated as the number of people who became ill divided by the number of people at risk for the illness. In order to **calculate** an **attack rate**, a case definition, or set of criteria to define the disease of interest, must first be developed.

Beside above, what is a rate in statistics? OECD **Statistics**. Definition: A **rate** refers to the occurrence of events over a specific interval in time. Similarly, a **rate** refers to the measure of the frequency of some phenomenon of interest.

Similarly one may ask, what is the difference between attack rate and incidence rate?

The denominator of an **incidence** proportion is the number of persons at the start of the observation period. Overall **attack rate** is the total number of new cases divided by the total population.

Is prevalence a rate or ratio?

A **prevalence rate** is the proportion of the population that has a health condition at a point in time. Therefore, these measures are not considered “true” **rates** by some, although use of the terminology is widespread. Table 3.2 summarizes some of the common epidemiologic measures as **ratios**, proportions, or **rates**.