Enter the incidence rate and the average duration of the condition into the calculator to determine the prevalence. This calculator helps in understanding the proportion of a population affected by a condition at a particular time.

## Incidence To Prevalence Formula

The following formula is used to calculate the prevalence from incidence rate and average duration of the condition.

P = I * D

Variables:

• P is the prevalence (per 1000 persons)
• I is the incidence rate (per 1000 person-years)
• D is the average duration of the condition (years)

To calculate the prevalence, multiply the incidence rate by the average duration of the condition.

## What is Prevalence?

Prevalence is a measure of the proportion of a population who have a specific characteristic in a given time period. In epidemiology, it is used to describe the proportion of people who have a particular disease or condition at a specific point in time or over a specified period. Prevalence helps public health officials understand the level of disease burden in a community and can inform healthcare planning and resource allocation.

## How to Calculate Prevalence from Incidence?

The following steps outline how to calculate the prevalence from incidence rate and average duration of the condition.

1. First, determine the incidence rate (I) per 1000 person-years.
2. Next, determine the average duration of the condition (D) in years.
3. Next, gather the formula from above = P = I * D.
4. Finally, calculate the prevalence (P) per 1000 persons.
5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem :

Use the following variables as an example problem to test your knowledge.

Incidence rate (I) = 5 per 1000 person-years

Average duration of the condition (D) = 8 years