VITAL DX v4.0 • VERIFIED QUANTITATIVE BRIEFING
Bayesian Positive Predictive Value: 90% Sens / 86% Spec / 2% Prevalence
With 90% sensitivity, 86% specificity, and 2% disease prevalence, the Positive Predictive Value (PPV) of a positive test is 11.6%.
Bayes Theorem: PPV = TP / (TP + FP) = (90% × 2%) / [(90% × 2%) + (14% × 98%)] = 11.6%.
FAQ: What is the PPV when sensitivity is 90%, specificity is 86%, and prevalence is 2%?
The Positive Predictive Value (PPV) is 11.6%, meaning 88.4% of positive results at 2% prevalence are false positives.