Enter the control group % and the experiment group % into the NNT calculator. The calculator will display the total number of patients that need to be treated to achieve an endpoint.

## Number Needed to Treat Formula

The following formula is used to calculate the total number of patients that need to be treated in order to achieve a result.

NNT=1/ARR

- Where NNT is the number of patients that need to be treated
- ARR is the absolute risk reduction

Furthermore, ARR can be calculated through the following equation.

ARR=CER - EER

- Where CER is the control event rate
- EER is the experiment event rate

## Number Needed to Treat Definition

Number Needed to Treat (NNT) is a statistical measure used in clinical research to quantify the effectiveness of a medical intervention or treatment. It represents the number of patients who need to be treated to prevent one additional outcome of interest, such as an adverse event or a specific health outcome.

NNT is calculated by comparing the outcome rates in two groups: the treatment group and the control group. The difference in the outcome rates between the two groups is then used to determine the NNT.

A lower NNT indicates a more effective treatment, as fewer patients need to be treated to achieve the desired outcome.

NNT helps clinicians and researchers assess the potential benefits and risks associated with a particular intervention. By quantifying the number of patients needed to be treated to observe a positive outcome, NNT helps inform medical decisions, resource allocation, and patient care.

## How to calculate number needed to treat?

How to calculate a number needed to treat?

**First, measure the control event rate**This will be the percent treated in the control event.

**Next, measure the experiment event rate**This will be the percent treated in the experiment.

**Lastly, calculate the NNT**Using the formula above and the information from steps 1-2 to calculate the NNT

## FAQ

**What is NNT?**

NNT stands for the number needed to treat. It’s a term used in medicine to describe the total number of patients needed to be treated in order to achieve a given result.