Table 1

Descriptive statistics of the original and bootstrap data sets

Variable(s)*	Original sample				Bootstrap sample
Variable(s)*	N	ANR no, n=784†	ANR yes, n=196†	P value‡	N	ANR no, n=52 777†	ANR yes, n=196†	P value‡
Gestational age 34–37 weeks	980	130 (17%)	63 (32%)	<0.001	52 973	8790 (17%)	63 (32%)	<0.001
Growth restriction	980	12 (1.5%)	11 (5.6%)	0.002	52 973	788 (1.5%)	11 (5.6%)	<0.001
Gestational diabetes	975	13 (1.7%)	4 (2.1%)	0.8	52 769	849 (1.6%)	4 (2.1%)	0.6
Meconium stained amniotic fluid	980	38 (4.8%)	72 (37%)	<0.001	52 973	2598 (4.9%)	72 (37%)	<0.001
Forceps or vacuum delivery	980	10 (1.3%)	13 (6.6%)	<0.001	52 973	673 (1.3%)	13 (6.6%)	<0.001
Chorioamnionitis	980	4 (0.5%)	6 (3.1%)	0.006	52 973	301 (0.6%)	6 (3.1%)	0.001
Fetal bradycardia	980	14 (1.8%)	54 (28%)	<0.001	52 973	1004 (1.9%)	54 (28%)	<0.001
Placental abruption	980	5 (0.6%)	24 (12%)	<0.001	52 973	323 (0.6%)	24 (12%)	<0.001
General anaesthesia	980	6 (0.8%)	23 (12%)	<0.001	52 973	465 (0.9%)	23 (12%)	<0.001
Emergency caesarean section	980	26 (3.3%)	64 (33%)	<0.001	52 973	1816 (3.4%)	64 (33%)	<0.001
Fetal bradycardia*Emergency c-section	980	7 (0.9%)	31 (16%)	<0.001	52 973	524 (1.0%)	31 (16%)	<0.001
Abruption*Emergency c-section	980	2 (0.3%)	22 (11%)	<0.001	52 973	131 (0.2%)	22 (11%)	<0.001

*Ten covariates from the original cohort including three antepartum and seven intrapartum factors, along with last two interaction terms which were not included in the original cohort.
†n (%).
‡Pearson’s χ² test; Fisher’s exact test.
ANR, advanced neonatal resuscitation.