Table 1.

Descriptive statistics for the development (N = 23747) and test (N = 5810) datasets.

Characteristics	Levels	DEVELOPMENT		TEST
		n	%	n	%
Birth weight (grams)	<1000	8801	37.06	2142	36.87
	1000–1500	14650	61.69	3616	62.24
	>1500	296	1.25	52	0.89
GA (weeks)	<26	3423	14.41	867	14.92
	26–30	12934	54.47	3204	55.15
	31–35	7218	30.40	1693	29.14
	>35	172	0.72	46	0.79
Apgar score (1 min.)	0–3	4206	17.71	950	16.35
	4–6	8355	35.18	2209	38.02
	7–10	11186	47.11	2651	45.63
Apgar score (5 min.)	0–3	760	3.20	149	2.56
	4–6	3096	13.04	754	12.98
	7–10	19891	83.76	4907	84.46
Sex	male	12006	50.56	2962	50.98
	female	11741	49.44	2848	49.02
Mode of Delivery	cesarean	19316	81.34	4689	80.71
	vaginal	4431	18.66	1121	19.29
Maternal race	black	1139	4.80	314	5.40
	hispanic	1561	6.57	374	6.44
	white	19705	82.98	4809	82.77
	asian	882	3.71	252	4.34
	other	460	1.94	61	1.05
Chorioamnionitis	no	20707	87.20	4951	85.22
	yes	3040	12.80	859	14.78
Prenatal care	no	1924	8.10	320	5.51
	yes	21823	91.90	5490	94.49
Antenatal steroids	no	4434	18.67	753	12.96
	yes	19313	81.33	5057	87.04
Maternal hypertension	no	17635	74.26	4365	75.13
	yes	6112	25.74	1445	24.87
Multiple birth	no	15780	66.45	3801	65.42
	yes	7967	33.55	2009	34.58
Died before discharge	no	20840	87.76	5147	88.59
	yes	2907	12.24	663	11.41

The development set refers to data from 2008 to 2014, the test set refers to data from 2015 to 2016.