Table 3.

The efficacy of PCT, CRP and WBC in the diagnosis of bacterial ARTI

Index	AUC (95% confidence interval)	Cut-off	Specificity (%)	Sensitivity (%)	Positive predictive value (%)	Negative predictive value (%)
PCT	0.65 (0.59–0.71)	0.49	74.80	56.5	50.4	79.1
CRP	0.55 (0.48–0.62)	10.63	72.3	46.3	43.1	74.8
WBC	0.58 (0.52–0.65)	11.40	81.1	31.5	43.0	72.3