Table IV.

Stratified receiver-operator characteristic analysis for defining serum procalcitonin (PCT) cut-off for predicting bacteraemia

Disease group	Serum PCT (ng/ml) cut-off for predicting bacteraemia	Sensitivity (%) (95% CI)	Specificity (%) (95% CI)
Age >65 yr (n=121)	>3.2	88.9 (51.8-99.7)	66.1 (56.5-74.7)
Age <65 yr (n=359)	>3.17	79.6 (64.7-90.2)	62.7 (57.1-68.1)
Males (n=268)	>3.2	82.1 (63.1-93.9)	60.4 (53.9-66.6)
Females (n=212)	>3.17	80.0 (59.3-93.2)	67.7 (60.5-74.4)
Patients with community acquired infection (n=450)	>3.2	81.8 (67.3-91.8)	65.0 (60.2-69.7)
Overall (n=480)	>3.2	81.1 (68.0-90.6)	63.6 (58.8-68.2)