How to use
- Choose whether you want to enter two rates or a direct signed risk increase.
- Enter percentages and decimal places, then calculate.
- Read the direction first, then the absolute increase and NNH.
Wave 12 clinical bridge
Absolute risk increase → NNH
The share URL stores only mode and decimal settings.
Where this fits
Use this page when the next question is people-needed interpretation for harm. ARR / NNT is the broader benefit-or-harm comparison page. Risk difference focuses on signed absolute difference without converting to people-needed language.
FAQ
What does this page calculate?
It converts control and exposed risk, or a direct risk increase, into absolute risk increase and number needed to harm.
What if the exposed group is safer?
The page reports a protective direction instead of harm. In that case you should interpret the result as number needed to benefit rather than NNH.
Can I enter a direct risk increase?
Yes. Switch to direct difference mode and enter the signed risk increase in percentage points.
Does the share URL contain my rates?
No. The share URL stores only light settings such as mode and decimal places. Numeric inputs stay in your browser.