Number Needed to Treat (NNT) Calculator

Calculate NNT



Formula

To calculate the Number Needed to Treat (NNT):

\[ NNT = \frac{1}{ARR} \]

Where:

To calculate the Absolute Risk Reduction (ARR):

\[ ARR = CER - EER \]

Where:

What is Number Needed to Treat (NNT)?

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.

Example Calculation

Let's assume the following values:

Using the formula:

\[ ARR = 0.30 - 0.20 = 0.10 \]

\[ NNT = \frac{1}{0.10} = 10 \]

The Number Needed to Treat is 10.