Derivation and Validation of a Risk Score to Predict Mortality of Early Neonates at Neonatal Intensive Care Unit: The END in NICU Score

Figures & data

Table 1 Simple and Multiple Binary Logistic Regression Between Predictor Variables and Discharge Status for Derivation and Validation of a Risk Score of Early Neonatal Death Among Early Neonates in Neonatal Intensive Care Unit, 2021

Variables	Discharge Status		COR (95% CI)	AOR(95% CI)	B-Coefficients of AOR	Score
	Died	Not Died
Birth APGAR score
0–3	32	10	27.27(12.82, 58.04)**	6.20(2.36, 16.30)**	1.824	4
4–6	119	320	3.17(2.27, 4.42)**	1.62 (1.05, 2.51)*	0.483	1
7–10	65	554	1	1		0
Presence of perinatal asphyxia
Yes	61	117	2.58(1.81, 3.68)**	5.23 (2.86, 9.59)**	1.655	3
No	155	767	1	1		0
Modes of delivery
Cesarean section	77	238	1.50(1.10, 2.06)*	3.89 (2.26, 6.70)**	1.357	3
Spontaneous delivery	139	646	1	1		0
Presence of respiratory distress syndrome
Yes	77	67	6.76(4.65, 9.81)**	4.67 (2.72, 8.03)**	1.542	3
No	139	817	1	1		0
Admission weight (gram)
<1500	105	64	11.88(7.94,17.76)**	3.96 (1.77, 8.88)**	1.377	3
1500–2499	44	335	0.95(0.63,1.43)	1.80 (1.32, 2.65)*	0.589	1
≥2500	67	485	1	1		0
Age of mother
≤20	15	129	1
21–29	48	312	1.32(0.72, 2.45)	1.43(0.65, 3.16)
≥30	153	443	2.97(1.69, 5.23)**	1.81(0.89,3.68)
Gestational age (weeks)
<32	148	124	14.60(10.07, 21.19)**	10.21 (5.23, 19.94)**	2.324	5
32–36	17	136	1.53(0.86, 2.73)	2.32 (1.07, 5.03)*	0.842	2
≥37	51	624	1	1		0
Sepsis
Yes	69	52	3.74(2.52, 5.57)**	5.38 (3.06, 9.45)**	1.683	4
No	815	164	1	1		0
Total score						29

Notes: **P-value<0.001, *P-value<0.05.

Abbreviations: APGAR, appearance, pulse, grimace, activity, and respiration; AOR, adjusted odds ratio; COR, crude odds ratio; CI, confidence interval.

Figure 1 The receiver operating curves with the area under the curve of the derivation datasets of the final multiple logistic regression model. (The solid green color shows the area under the curve with surrounding 95% CI. While the dotted line at the middle (a ROC curve close to the y = x or 45-degree line) is an reference line for poor model with no predictive).

Figure 2 The density plots of the derivation datasets of the final multivariate model. (The red one represents early neonates who are at low risk of death and the blue one those who are at high risk of death).

Table 2 Baseline Characteristics of Study Participants for Derivation and Validation of a Risk Score of Early Neonatal Death Among Early Neonates in Neonatal Intensive Care Unit 2021 (N= 1100)

Variables	Response	Frequency	Percent
Sex of the neonate	Male	617	56.1
	Female	483	43.9
Age at admission	≤24 hours	793	72.1
	24–72 hours	158	14.4
	≥ 72 hours	149	13.5
Admission weight (gram)	<1500	169	15.4
	1500–2499	379	34.5
	≥2500	552	50.2
Admission temperature	<36	563	51.2
	36–36.4	113	10.3
	36.5–37.5	278	25.3
	>37.5	146	13.3
Admission heart rate	<100	38	3.5
	100–160	849	77.2
	>160	213	19.4
Admission respiratory rate	<30	53	4.8
	30–60	710	64.5
	60	337	30.6
Gestational age (weeks)	<32	272	24.7
	32–36	153	13.9
	≥37	675	61.4
Mode of delivery	Cesarean section	315	28.6
	Spontaneous delivery	785	71.4
Place of delivery	Home delivery	102	9.3
	Same facility	998	90.7
APGAR score at birth	0–3	42	3.8
	4–6	439	39.9
	7–10	619	56.3
Birth weight (gram)	<1500	158	14.4
	1500–2499	381	34.6
	≥2500	561	51.0
Prematurity	Yes	425	38.6
	No	675	61.4
Low birth weight	Yes	539	49.0
	No	561	51.0
Sepsis	Yes	121	11.0
	No	979	89.0
RDS	Yes	144	13.1
	No	956	86.9
Perinatal asphyxia	Yes	178	16.2
	No	922	83.8
Congenital malformation	Yes	37	3.4
	No	1063	96.6
Age of mother	≤20	144	13.1
	21–29	360	32.7
	≥30	596	54.2
Residence of mother	Urban	523	47.5
	Rural	577	52.5
Gravidity	1	130	11.8
	2–4	811	73.7
	≥5	159	14.5
Parity	1	60	5.5
	2–4	923	83.9
	≥5	117	10.6
TT vaccination status	No not vaccinated	76	6.9
	Unknown	4	0.4
	Yes vaccinated	690	62.7
	Missing data	330	30.0
Number ANC attended	1–3	570	51.8
	≥4	200	18.2
	Missing data	330	30.0
Discharge status	Not died	884	80.4
	Died	216	19.6

Abbreviations: PICT, Provider Initiated Counseling and Testing; APGAR, appearance, pulse, grimace, activity, and respiration; VDRL, The Venereal Disease Research Laboratory test; TT, tetanus toxoid; RDS, respiratory distress syndrome; ANC, antenatal care.

Figure 3 Decision curve for a model to predict early neonatal death in early neonates admitted to neonatal intensive care unit. (The apparent curve model (red broken line in the middle) show a curve with variables in the final model; red small broken line in two sides show 95% CI of the apparent curve; Blue line show the cross validated model. Black horizontal line at the bottom is null model without independent variables. While three black line falling from left to right show all model).

Figure 4 Calibration plots of derivation datasets. Calibration plots demonstrating observed versus predicted probability of early neonatal intensive care unit mortality in the derivation dataset from the multiple regression models. (Red line show the calibration of predicted versus the observed probabilities; black area around the red show the 95% CI of the calibration).