Table 2.

Basic characteristics of the study population (n = 54,599)

Characteristic	Category	No	%
Health facility	Sardjito hospital	13,726	25.1
	District hospitals	30,574	56.0
	Health centers	10,299	18.9
Gender	Boys	29,112	53.3
	Girls	25,487	46.7
Birth order	First (1st child)	26,189	48.0
	Later (≥2nd child)	28,410	52.0
Admitted to neonatal ward	Born in the hospital/health centre	45,414	83.2
	Referred <24 h	9,185	16.8
Education of mother (years)	≤5	1,803	3.8
	6–12	40,196	82.7
	≥13	6,576	13.5
Age of mother (years)	≤19	1,770	3.3
	20–34	43,737	81.0
	≥35	8,456	15.7
Number of registered infants	Birth weight	54,599	100
	Length	52,261	95.7
	Head circumference	48,109	88.1