VITAL DX v4.0 • VERIFIED QUANTITATIVE BRIEFING

Bayesian Positive Predictive Value: 82% Sens / 80% Spec / 10% Prevalence

With 82% sensitivity, 80% specificity, and 10% disease prevalence, the Positive Predictive Value (PPV) of a positive test is 31.3%.

Bayes Theorem: PPV = TP / (TP + FP) = (82% × 10%) / [(82% × 10%) + (20% × 90%)] = 31.3%.
FAQ: What is the PPV when sensitivity is 82%, specificity is 80%, and prevalence is 10%?

The Positive Predictive Value (PPV) is 31.3%, meaning 68.7% of positive results at 10% prevalence are false positives.