VITAL DX v4.0 • VERIFIED QUANTITATIVE BRIEFING
Bayesian Positive Predictive Value: 84% Sens / 94% Spec / 2% Prevalence
With 84% sensitivity, 94% specificity, and 2% disease prevalence, the Positive Predictive Value (PPV) of a positive test is 22.2%.
Bayes Theorem: PPV = TP / (TP + FP) = (84% × 2%) / [(84% × 2%) + (6% × 98%)] = 22.2%.
FAQ: What is the PPV when sensitivity is 84%, specificity is 94%, and prevalence is 2%?
The Positive Predictive Value (PPV) is 22.2%, meaning 77.8% of positive results at 2% prevalence are false positives.