Enter the control event rate and the experimental event rate into the calculator to determine the absolute risk reduction.
- Relative Risk Calculator
- Number Needed to Treat Calculator (NNT)
- Weight Loss Calculator
- Attributable Risk Calculator
Absolute Risk Reduction Formula
The following equation is used to calculate an absolute risk reduction.
ARR = CER – EER
- Where ARR is the absolute risk reduction (%)
- CER is the control event rate (%)
- EER is the experimental event rate (%)
Absolute Risk Reduction Definition
An absolute risk reduction is defined as the difference between the percentage rate of a control event and a experimental rate.
Absolute Risk Reduction Example
How to calculate absolute risk reduction?
- First, determine the control rate.
Calculate the percentage rate of the control event rate.
- Next, determine the experimental event rate.
Calculate the experimental event rate.
- Finally, calculate the absolute risk reduction.
Calculate the absolute risk reduction using the formula above.
An absolute risk reduction, or ARR for short, is a measure of the absolute difference between a control group and a group receiving a treatment to prevent the event from happening.
An absolute risk is a ratio of the number of people that have a particular event, typically a medical event, compared to the total number of people that it could happen to.