Number Needed to Treat Calculator (NNT)

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.

• Absolute Risk Reduction Calculator
• Incidence Rate Calculator
• Attributable Risk Calculator

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?

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