VITAL DX v4.0 • VERIFIED QUANTITATIVE BRIEFING
Bayesian Positive Predictive Value: 90% Sens / 92% Spec / 10% Prevalence
With 90% sensitivity, 92% specificity, and 10% disease prevalence, the Positive Predictive Value (PPV) of a positive test is 55.6%.
Bayes Theorem: PPV = TP / (TP + FP) = (90% × 10%) / [(90% × 10%) + (8% × 90%)] = 55.6%.
FAQ: What is the PPV when sensitivity is 90%, specificity is 92%, and prevalence is 10%?
The Positive Predictive Value (PPV) is 55.6%, meaning 44.4% of positive results at 10% prevalence are false positives.