The Role of Albumin in the Diagnosis of Neonatal Sepsis Over the Last 11 Years: A Retrospective Study

Figures & data

Table 1 Baseline Characteristics of the Infection and Sepsis Group

Variables	Infection (n=1317)	Sepsis (n=732)	P
Gestational age (weeks)	39 (38, 40)	38 (33.5, 39)	<0.001
Age (days)	2.00 (1.00, 3.00)	4.00 (2.00, 16.00)	<0.001
Male, n (%)	819 (62.19%)	455 (62.16%)	1.000
Weight (kg)	3.12±0.82	2.69±0.92	<0.001
Temperature (°C)	36.92±9.14	37.23 ± 0.92	0.361
Respiratory (rate/minute)	47.78±7.20	53.38 ± 10.98	<0.001
Heart rate (bpm)	137.99±11.08	144.6 ± 19.82	<0.001
SBP (mm Hg)	71.52±5.95	70.22 ± 8.64	<0.001
DBP (mm Hg)	41.02±6.19	39.86 ± 8.08	<0.001
CRP (ng/mL)	11.25 (2.20, 19.85)	34.00 (12.35, 58.10)	<0.001
PCT (ng/mL)	0.92 (0.30, 2.47)	5.40 (0.76, 23.18)	<0.001
Biochemical parameters
TBIL (μmol/L)	209.00 (143.00, 263.20)	106.00 (45.35, 164.55)	<0.001
ALT (U/L)	11.00 (8.00, 14.60)	9.00 (6.00, 13.20)	<0.001
AST (U/L)	43.00 (32.40, 57.90)	36.00 (24.00, 55.00)	<0.001
TP (g/L)	52.70 (49.60, 56.00)	50.00 (44.45, 54.00)	<0.001
ALB (g/L)	36.00 (34.00, 38.30)	35.00 (31.00, 37.35)	<0.001
UREA (mmol/L)	3.03 (2.27, 4.00)	3.70 (2.70, 5.00)	<0.001
CREA (μmol/L)	55.00 (44.00, 66.00)	52.00 (33.00, 70.00)	0.003
UA (μmol/L)	270.00 (194.00, 349.00)	248.00 (165.00, 369.00)	0.007
Haematologic parameters
WBC (10^9 cells/L)	14.14 (10.86, 18.88)	11.91 (7.37, 18.19)	<0.001
Platelet (10^9/L)	267 (225, 319)	231 (172, 305)	<0.001
Neutrophil count (10^9 cells/L)	9.00 (6.14, 13.20)	7.24 (3.61, 12.40)	<0.001
Lymphocyte count (10^9 cells/L)	3.26 (2.59, 4.15)	2.83 (1.72, 4.20)	<0.001

Abbreviations: SBP, systolic blood pressure; DBP, diastolic blood pressure; CRP, C-reactive protein; PCT, procalcitonin; TBIL, total bilirubin; AST, aspartate aminotransferase; ALT, alanine aminotransferase; TP, total protein; ALB, albumin; UREA, urea nitrogen; CREA, creatinine; UA, uric acid; WBC, white blood cell.

Table 2 Multivariate Logistic Regression Analysis for Prediction of Neonatal Sepsis

Quartile	Range of Values	Basic Model			Adjusted Model
		n/N (%)	OR (95% CI)	P	n/N (%)	OR (95% CI)	P
	CRP (ng/mL)	732/2000 (36.60)	1.05 (1.05, 1.06)	<0.001	724/1953 (37.00)	1.06 (1.06, 1.07)	<0.001
Q1	≤4.1	87/501 (17.37)	1		86/478 (17.99)	1
Q2	4.1~14.6	115/500 (23.00)	1.42 (1.04, 1.94)	0.027	112/490 (22.86)	2.08 (1.42, 3.04)	0.001
Q3	14.6~31.3	148/500 (29.60)	2.00 (1.48, 2.70)	<0.001	147/493 (29.82)	3.54 (2.45, 5.13)	<0.001
Q4	>31.3	382/499 (76.55)	15.54 (11.39, 21.19)	<0.001	379/492 (77.03)	26.97 (18.28, 39.79)	<0.001
	PCT (ng/mL)	724/2018 (35.88)	1.11 (1.09, 1.13)	<0.001	716/1971 (36.00)	1.11 (1.09, 1.13)	<0.001
Q1	≤0.40	128/538 (23.79)	1		126/516 (24.42)	1
Q2	0.40~1.34	95/472 (20.13)	0.81 (0.60, 1.09)	0.162	95/464 (20.47)	0.94 (0.66, 1.35)	0.754
Q3	1.34~5.62	143/503 (28.43)	1.27 (0.96, 1.68)	0.089	141/493 (28.60)	2.08 (1.50, 2.90)	<0.001
Q4	>5.62	358/505 (70.89)	7.80 (5.92, 10.28)	<0.001	354/498 (71.08)	10.75 (7.76, 14.90)	<0.001
	ALB (g/L)	699/1924 (36.33)	0.88 (0.86, 0.90)	<0.001	691/1878 (37.00)	0.93 (0.90, 0.95)	<0.001
Q1	≤33.0	287/491 (58.45)	3.14 (2.40, 4.11)	<0.001	139/440 (31.59)	2.13 (1.54, 2.95)	<0.001
Q2	33.0~35.9	121/473 (25.58)	0.77 (0.58, 1.02)	0.071	285/481 (59.25)	0.80 (0.58, 1.10)	0.175
Q3	35.9~38.0	150/504 (29.76)	0.95 (0.72, 1.25)	0.696	121/464 (26.08)	1.03 (0.76, 1.40)	0.837
Q4	>38.0	141/456 (30.92)	1		146/493 (29.61)	1
	WBC (10^9 cells/L)	732/2047 (35.76)	0.97 (0.96, 0.98)	<0.001	724/1998 (36)	1.00 (0.99, 1.01)	0.979
Q1	≤9.93	279/514 (54.28)	1		279/508 (54.92)	1
Q2	9.93~13.62	145/510 (28.43)	0.33 (0.26, 0.43)	<0.001	143/499 (28.66)	0.56 (0.41, 0.75)	<0.001
Q3	13.62~18.60	136/511 (26.61)	0.31 (0.24, 0.40)	<0.001	132/494 (26.72)	0.57 (0.42, 0.77)	<0.001
Q4	>18.60	172/512 (33.59)	0.43 (0.33, 0.55)	<0.001	170/497 (34.21)	0.88 (0.65, 1.19)	0.411

Note: Basic model: unadjusted; adjusted model: adjusted for gestational age, age, sex, and weight.

Abbreviations: CRP, C-reactive protein; PCT, procalcitonin; ALB, albumin; WBC, white blood cell.

Table 3 Cut-off Values of Inflammatory Biomarkers for Neonatal Sepsis Diagnosis

Indicator	Cut-off Values	AUC (95% CI)	Sensitivity (95% CI), %	Specificity (95% CI), %	Accuracy, %	PPV/NPV, %	PLR/NLR, %
CRP	25.35	0.767 (0.744, 0.789)	59.6 (56, 63.1)	84.6 (82.6, 86.6)	75.4	69.1/78.4	3.873/0.478
PCT	5.955	0.725 (0.700, 0.750)	48.3 (44.7, 52.0)	90.1 (88.5, 91.7)	75.1	73.2/75.7	4.887/0.573
WBC	10.305	0.598 (0.571, 0.626)	41.1 (37.6, 44.7)	79.6 (77.4, 81.8)	65.9	52.9/70.8	2.018/0.740
ALB	33.05	0.625 (0.598, 0.652)	41.1 (37.4, 44.7)	83.3 (81.3, 85.4)	68	58.5/71.2	2.466/0.707
CRP+PCT	—	0.826 (0.805, 0.847)	63.8 (60.3, 67.3)	91.8 (90.3, 93.3)	81.6	81.8/81.5	7.788/0.394
CRP+ALB	—	0.795 (0.773, 0.817)	62.7 (59.1, 66.2)	84.8 (82.7, 86.8)	76.6	70.6/79.5	4.111/0.441
PCT+ALB	—	0.749 (0.724, 0.774)	57.4 (53.8, 61.1)	86.9 (85.0, 88.8)	76.2	71.5/78.2	4.389/0.490
CRP+PCT+ALB	—	0.834 (0.813, 0.855)	64.6 (61.1, 68.2)	92.9 (91.5, 94.4)	82.5	84.2/81.8	9.127/0.380
CRP+PCT+ALB+WBC	—	0.837 (0.816, 0.857)	68.8 (65.4, 72.3)	89.5 (87.8, 91.3)	81.9	79.4/83.1	6.583/0.348

Abbreviations: CRP, C-reactive protein; PCT, procalcitonin; ALB, albumin; WBC, white blood cell; CI, confidence interval; NLR, negative likelihood ratio; NPV, negative predictive value; PLR, positive likelihood ratio; PPV, positive predictive value.

Figure 1 Receiver operating characteristic (ROC) curves of ALB, PCT, and CRP levels and the WBC count as inflammatory biomarkers of neonatal sepsis.

Table 4 Test for a Difference in Two ROC Curves

	CRP+PCT+ALB
	Z value	P
CRP+PCT	−2.18	0.029
CRP+ALB	−7.01	<0.001
PCT+ALB	−8.26	<0.001
CRP+PCT+ALB+WBC	1.31	0.19

Abbreviations: CRP, C-reactive protein; PCT, procalcitonin; ALB, albumin; WBC, white blood cell.