Negative predictive value

Assistant Editor(s)-In-Chief: Kristin Feeney, B.S.

Overview
The negative predictive value is the proportion of individuals without preclinical disease who test negative using the specified testing modality.

Definition
The Negative Predictive Value can be defined as:

$$ NPV = \frac{\rm number\ of\ True\ Negatives}{{\rm number\ of\ True\ Negatives}+{\rm number\ of\ False\ Negatives}}$$

or, alternatively,

$$ NPV = \frac{({\rm specficity}) ({\rm 1 - prevalence})}{({\rm specificity}) ({\rm 1 - prevalence}) + (1 - {\rm sensitivity}) ({\rm prevalence})} $$

Related Chapters

 * Positive predictive value
 * Binary classification