Table 6.

Performance of procalcitonin at birth, at 12–24 h, and 36–48 h of life for the diagnosis of neonatal sepsis of vertical transmission (cutoff points selected to achieve 90% sensitivity).

	At birth n = 205	12–24 h of life n = 212	36–48 h of life n = 193
Cutoff, ng/ml	≥0.15	≥1.2	≥0.75
Sensitivity, % (95% CI)	91.2 (81.1 – 96.2)	90.2 (80.2 – 95.4)	91.8 (80.8 – 96.8%)
Specificity (95% CI)	10.8 (6.8 – 16.8)	43.0 (35.4 – 51.0)	51.4 (43.3 – 59.4)
Youden's index	0.02	0.33	0.43
PPV (95% CI)	28.3 (22.3 – 35.2)	39.0 (31.3 – 47.2)	55.9 (44.1 – 67.1)
NPV (95% CI)	76.2 (54.9 – 89.4)	91.5 (82.8 – 96.1)	91.2 (84.9 – 95.0)
LR+ (95% CI)	1.02 (0.93 – 1.13)	1.58 (1.35 – 1.86)	1.89 (1.57 – 2.28)
LR- (95% CI)	0.81 (0.32 – 2.07)	0.23 (0.10–0.50)	0.16 (0.06 – 0.41)

PPV: positive predictive value, NPV: negative predictive value, LR+: likelihood ratio of a positive result, LR-: likelihood ratio of a negative result.