Table 4.

Mortality rates of very low birth weight infants (≤1,500 g).

Author	Country	Year(s)	Methods	Age of infants	Mortality outcome	Reasons for death
Shim et al. (30)	Korea	2009	Data for 2,584 very low birth weight infants admitted to NICUs in 76 hospitals	Not listed	Mortality rate for infants with birth weight of <750 g: 44.8% Mortality rate for infants with birth weight of 750–999 g: 20.4% Mortality rate for infants with birth weight of 1,000–1,499 g: 6.5%	Not listed
Battin et al. (32)	New Zealand	1959–2009	Data for very low birth weight (≤1,500 g) infants born at a single tertiary neonatal unit	Not listed	Mortality rate of infants with birth weight of 501–1,000 g in 2009: 30% Mortality rate of infants with birth weight of 1,001–1,500 g in 2009: 5%	2008: prematurity and early cardiorespiratory problems (predominantly RDS) (33%), infection (29%), congenital anomalies (12%), NEC (12%)
Lake et al. (39)	United States of America	2007–2008	Data for 72,235 very low birth weight (501–1,500 g) infants born at 558 Vermont Oxford Network hospital NICUs	Mean GA: 28.2 weeks (n = 72,235)	12.9% (9,278/71,936)	Not listed

g, grams; GA, gestational age; n, number; NEC, necrotizing enterocolitis; NICU, neonatal intensive care unit; RDS, respiratory distress syndrome.