VITAL DX v4.0 • VERIFIED QUANTITATIVE BRIEFING

Bayesian Positive Predictive Value: 94% Sens / 84% Spec / 2% Prevalence

With 94% sensitivity, 84% specificity, and 2% disease prevalence, the Positive Predictive Value (PPV) of a positive test is 10.7%.

Bayes Theorem: PPV = TP / (TP + FP) = (94% × 2%) / [(94% × 2%) + (16% × 98%)] = 10.7%.
FAQ: What is the PPV when sensitivity is 94%, specificity is 84%, and prevalence is 2%?

The Positive Predictive Value (PPV) is 10.7%, meaning 89.3% of positive results at 2% prevalence are false positives.