VITAL DX v4.0 • VERIFIED QUANTITATIVE BRIEFING
Bayesian Positive Predictive Value: 86% Sens / 88% Spec / 2% Prevalence
With 86% sensitivity, 88% specificity, and 2% disease prevalence, the Positive Predictive Value (PPV) of a positive test is 12.8%.
Bayes Theorem: PPV = TP / (TP + FP) = (86% × 2%) / [(86% × 2%) + (12% × 98%)] = 12.8%.
FAQ: What is the PPV when sensitivity is 86%, specificity is 88%, and prevalence is 2%?
The Positive Predictive Value (PPV) is 12.8%, meaning 87.2% of positive results at 2% prevalence are false positives.