VITAL DX v4.0 • VERIFIED QUANTITATIVE BRIEFING
Bayesian Positive Predictive Value: 82% Sens / 82% Spec / 2% Prevalence
With 82% sensitivity, 82% specificity, and 2% disease prevalence, the Positive Predictive Value (PPV) of a positive test is 8.5%.
Bayes Theorem: PPV = TP / (TP + FP) = (82% × 2%) / [(82% × 2%) + (18% × 98%)] = 8.5%.
FAQ: What is the PPV when sensitivity is 82%, specificity is 82%, and prevalence is 2%?
The Positive Predictive Value (PPV) is 8.5%, meaning 91.5% of positive results at 2% prevalence are false positives.