##  [Absolute Risk Reduction](/index.php/absolute-risk-reduction) 

  ##  [Absolute Risk Reduction](https://health.quantumdictionary.io/absolute-risk-reduction-0) 

  

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**Health & Life Sciences Dictionary**

 







 

 

 

 



 

 

 

 

Definition

The absolute difference in event probabilities between a control (or untreated) group and an intervention group over a specified period: ARR = risk_control − risk_treatment; reported as a proportion or percentage and forming the basis for NNT calculation.