VITAL DX v4.0 • VERIFIED QUANTITATIVE BRIEFING
Bayesian Positive Predictive Value: 88% Sens / 80% Spec / 2% Prevalence
With 88% sensitivity, 80% specificity, and 2% disease prevalence, the Positive Predictive Value (PPV) of a positive test is 8.2%.
Bayes Theorem: PPV = TP / (TP + FP) = (88% × 2%) / [(88% × 2%) + (20% × 98%)] = 8.2%.
FAQ: What is the PPV when sensitivity is 88%, specificity is 80%, and prevalence is 2%?
The Positive Predictive Value (PPV) is 8.2%, meaning 91.8% of positive results at 2% prevalence are false positives.