To the Editor: In their meta-analysis of studies published between 1979 and 2008, Ms Lasswell and colleagues1 determined that very low-birth-weight (VLBW) infants (<1501 g) or very preterm (VPT) infants (<33 weeks) born outside level III perinatal hospitals had significantly higher mortality rates than those born in level III centers. It was initially not clear why several publications from the Victorian Infant Collaborative Study Group2- 4 were not included among the meta-analyzed studies. However, based on the inclusion criteria, perhaps the explanation was that the major outcome had to be either neonatal mortality (first 28 days of life) or mortality before hospital discharge. The Victorian Infant Collaborative Study Group had reported mortality rates to 2 years of age to ensure that the occasional death after discharge related to complications of prematurity was not missed.
Doyle LW. Regionalized Perinatal Care Systems and Very Low-Birth-Weight and Very Preterm Infants. JAMA. 2010;304(24):2696-2697. doi:10.1001/jama.2010.1856