Table 2

Test characteristics of procalcitonin (PCT) in the diagnosis of neonatal sepsis

PCT cut point (ng/mL), ≥	Sensitivity (95% CI)	Specificity (95% CI)	Youden’s index	Area under the curve	Reference standard(s)	Total Patients, n	Disease, n*	Studies, n	I²
All included studies
0.5	0.81 (0.75 to 0.86)	0.66 (0.53 to 0.77)	0.47	0.82 (0.74, 0.85)	Blood culture and clinical sepsis	3963	444	15	3.5–5.5
1.0	0.67 (0.46 to 0.83)	0.85 (0.63 to 0.95)	0.52	0.79 (0.55, 0.90)	Blood culture and clinical sepsis	567	66	5	3.4–4.2
1.7	0.81 (0.72 to 0.87)	0.71 (0.50 to 0.85)	0.52	0.83 (0.71, 0.88)	Blood culture and clinical sepsis	433	152	3	0
2.0	0.75 (0.69 to 0.81)	0.75 (0.59 to 0.86)	0.50	0.78 (0.69, 0.81)	Blood culture and clinical sepsis	3133	312	13	5.8–6.7
0.5	0.83 (0.76 to 0.88)	0.65 (0.52 to 0.77)	0.48	0.83 (0.73, 0.86)	Blood culture	3777	399	14	4.2–6.4
2.0	0.75 (0.68 to 0.80)	0.73 (0.56 to 0.85)	0.48	0.77 (0.68, 0.82)	Blood culture	2974	258	11	7.3–8.7
High-income countries only
0.5	0.75 (0.69 to 0.80)	0.71 (0.58 to 0.82)	0.46	0.75 (0.70, 0.82)	Blood culture and clinical sepsis	3346	244	8	0.3–0.4
0.5	0.75 (0.68 to 0.80)	0.71 (0.55 to 0.83)	0.46	0.75 (0.69, 0.82)	Blood culture	3160	199	7	0.7–0.9
1.0	0.71 (0.46 to 0.87)	0.84 (0.54 to 0.96)	0.55	0.81 (0.56, 0.92)	Blood culture	500	62	4	5.6–6.6
2.0	0.74 (0.59 to 0.85)	0.67 (0.36 to 0.88)	0.41	0.77 (0.63, 0.83)	Blood culture	2405	85	5	0.5–0.7
Low- and middle-income countries only
2.0	0.77 (0.71 to 0.83)	0.78 (0.60 to 0.90)	0.55	0.79 (0.71, 0.86)	Blood culture and clinical sepsis	728	227	8	8.7–9.2
0.5	0.89 (0.80 to 0.95)	0.58 (0.36 to 0.78)	0.47	0.87 (0.70, 0.92)	Blood culture	617	200	7	10.7–15.6
2.0	0.77 (0.68 to 0.84)	0.75 (0.56 to 0.88)	0.52	0.80 (0.69, 0.88)	Blood culture	569	173	6	12.5–13.7

*Defined as positive for disease using reference standard.