##  [Odds Ratio](/index.php/odds-ratio) 

  ##  [Odds Ratio](https://health.quantumdictionary.io/odds-ratio-0) 

  

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**Health & Life Sciences Dictionary**

 







 

 

 

 



 

 

 

 

Definition

The ratio of the odds of an outcome in one group to the odds in another group; for a 2×2 table with outcome present/absent and exposure yes/no, OR = (a/b)/(c/d) = ad/bc. It quantifies association between exposure and outcome but compares odds (p/(1−p)), not probabilities (p).