Fig. 3

C-reactive protein ROC curves predicting definite community-acquired pneumonia diagnosis. AUC = 0.787. 95 % CI = 0.717 to 0.857. Youden’s index = 0.501 for an optimal CRP cut-off point at 45.9 mg/L ROC receiver operating characteristic, AUC area under the curve, CI confidence interval, CRP C-reactive protein