Preemies Not Born in Specialized Level III Hospitals More Likely to Die

From Medscape Medical News

Fran Lowry

August 31, 2010 — Very low birth weight (VLBW) and very preterm (VPT) infants who are born in centers that are not specially equipped or experienced to manage such births have higher rates of neonatal and predischarge death compared with similar infants who are born in highly specialized level III hospitals.

The finding, from an analysis of data from previously published studies, appears in the September issue of the Journal of the American Medical Association.

"For more than 30 years, guidelines for perinatal regionalization have recommended that [VLBW] infants be born at highly specialized hospitals, most commonly designated as level III hospitals," write Sarah Marie Lasswell, MPH, from the Centers for Disease Control and Prevention, Atlanta, Georgia, and colleagues. "Despite these recommendations, some regions continue to have large percentages of VLBW infants born in lower-level hospitals."

The aim of this study was to evaluate the relationship between hospital level and care at birth and neonatal (the first 4 weeks after birth) and predischarge mortality for VLBW infants weighing 1500 g (53 ounces) or less and for VPT infants of 32 weeks' or less gestation.

In analyzing data from 37 VLBW studies comprising 104,944 infants, the investigators found that there was a 62% increase in odds of neonatal and predischarge death for infants born in non–level III hospitals compared with those born in level III hospitals (38% vs 23%; adjusted odds ratio [OR], 1.62; 95% confidence interval [CI], 1.44 - 1.83).

When the investigators restricted their analysis to 9 studies with higher-quality evidence comprising 46,318 infants, they noted similar results. There was a 60% increase in the odds of neonatal or predischarge mortality for VLBW infants born at non–level III hospitals compared with infants born in level III hospitals (36% vs 21%; adjusted OR, 1.60; 95% CI, 1.33 - 1.92).

Results were even worse for extremely low birth weight infants — weighing 1300 g (35 ounces) or less — born in non–level III hospitals. Those infants had an estimated 80% increase in odds of neonatal or predischarge mortality compared with infants born at level III hospitals (59% vs 32%; adjusted OR, 1.80; 95% CI, 1.31 - 2.46.)

Data from an analysis of 4 studies comprising 9300 infants showed that VPT infants born in lower-level hospitals had a 55% increase in odds of neonatal or predischarge mortality compared with infants born in level III hospitals (15% vs 17%). When only the 3 studies that were ranked as adequate and high quality were analyzed, the estimate of death was reduced to a 42% increased odds of death (7% vs 12%; adjusted OR, 1.42; 95% CI, 1.06 - 1.88).

The researchers add that meta-regression by year of publication did not reveal a change over time (slope, 0.00; P = .87).

Among the study limitations, the authors note that they excluded non-English studies and unpublished data from their meta-analysis and suggest this might be a potential source of bias in their study selection. Other potential causes of bias include inadequate definitions of hospital levels, inadequate descriptions of hospital capabilities, and variability of confounding factors among the studies.

"The results of this review confirm a primary premise on which perinatal regionalization systems are based: high risk infants have higher mortality rates when born outside hospitals with the most specialized levels of care," the authors conclude. "Although they represent less than 2% of U.S. births, 55% of infant deaths occur among VLBW infants. Strengthening perinatal regionalization systems in states with high percentages of VLBW and VPT infants born outside of level III centers could potentially save thousands of infant lives every year."

JAMA. 2010;304:992-1000.