VITAL DX v4.0 • VERIFIED QUANTITATIVE BRIEFING

Bayesian Positive Predictive Value: 98% Sens / 84% Spec / 10% Prevalence

With 98% sensitivity, 84% specificity, and 10% disease prevalence, the Positive Predictive Value (PPV) of a positive test is 40.5%.

Bayes Theorem: PPV = TP / (TP + FP) = (98% × 10%) / [(98% × 10%) + (16% × 90%)] = 40.5%.
FAQ: What is the PPV when sensitivity is 98%, specificity is 84%, and prevalence is 10%?

The Positive Predictive Value (PPV) is 40.5%, meaning 59.5% of positive results at 10% prevalence are false positives.