Based on these AUCs, we further assessed the sensitivity, specificity, PPV and NPV at CRP cut-offs of ≥ 40 mg/L, ≥ 60 mg/L and ≥ 100 mg/L, for differentiating bacterial from presumed viral plus other pneumonias, and definite bacterial from presumed viral pneumonias (Additional file 1: Table S3). Here, CRP is linked to viral pneumonia.