# How do you calculate prevalence?

## How do you calculate prevalence?

What is Prevalence?

- To estimate prevalence, researchers randomly select a sample (smaller group) from the entire population they want to describe.
- For a representative sample, prevalence is the number of people in the sample with the characteristic of interest, divided by the total number of people in the sample.

**Why do we calculate prevalence?**

Prevalence indicates the probability that a member of the population has a given condition at a point in time. It is, therefore, a way of assessing the overall burden of disease in the population, so it is a useful measure for administrators when assessing the need for services or treatment facilities.

**What do we mean by prevalence?**

Prevalence is a statistical concept referring to the number of cases of a disease that are present in a particular population at a given time, whereas incidence refers to the number of new cases that develop in a given period of time.

### What is the difference between prevalence and frequency?

To describe how often a disease or another health event occurs in a population, different measures of disease frequency can be used. The prevalence reflects the number of existing cases of a disease.

**What is the ubiquity?**

: presence everywhere or in many places especially simultaneously : omnipresence.

**What is the frequency of a disease?**

Measures of disease frequency are used to describe how common an illness (or other health event) is with reference to the size of the population (the population at risk) and a measure of time.

#### How to calculate the prevalence rate of a disease?

The following formula is used to calculate the prevalence rate of a disease. P (%) = TC / TP *100 Where P (%) is the prevalence rate TC is the total number of cases

**How is prevalence calculated in a representative sample?**

For a representative sample, prevalence is the number of people in the sample with the characteristic of interest, divided by the total number of people in the sample. # of people in sample with characteristic Prevalence = ━━━━━━━━━━━━━━━━━━━ Total # of people in sample

**What is the difference between incidence and prevalence?**

Incidence is a measure of the number of new cases of a characteristic that develop in a population in a specified time period; whereas prevalence is the proportion of a population who have a specific characteristic in a given time period, regardless of when they first developed the characteristic.

## Which is the best definition of point prevalence?

Point prevalence is the proportion of a population that has the characteristic at a specific point in time. Period prevalence is the proportion of a population that has the characteristic at any point during a given time period of interest. “Past 12 months” is a commonly used period.