Black babies with very low birth weights more likely to be born in hospitals with high neonatal death rates

Mar 4 2008

In New York City, black babies with very low birth weights (less than 1,500 grams, or 3 pounds, 5 ounces) are more likely to be born in hospitals with high risk-adjusted neonatal death rates, according to a Commonwealth Fund-supported study in the March issue of Pediatrics.

White very low birth weight (VLBW) babies are less likely to be born in hospitals with high risk-adjusted neonatal death rates. In fact, only 11 percent of white VLBW babies were born at hospitals with high death rates while 21 percent of black VLBW babies were born at those hospitals.

The study, conducted by researchers at Mount Sinai School of Medicine, found that if black mothers having VLBW babies gave birth at the same hospitals as white mothers of VLBW babies, death rates for black VLBW babies would fall nearly 5 percent, to a rate of 132 deaths for every 1,000 VLBW births in New York City hospitals. This would reduce the disparity that currently exists between black and white VLBW deaths by 34%.

“It is important to understand why black very low birth weight infants in New York City are more likely to die in their first month of life than white infants. This study tells us that a big part of that difference can be attributed to the hospital where the baby is born,” says lead study author Elizabeth Howell, M.D., of the Department of Health Policy at Mount Sinai School of Medicine. “It further tells us that we have an opportunity to save the lives of babies and eliminate a significant portion of the black-white gap.”

In addition to the disparity in where black and white VLBW babies are born, the authors also found a striking variation in the neonatal death rates for VLBW babies in New York City hospitals. The death rates ranged from 9.6 to 27.2 deaths for every 1,000 births and standardized mortality rates (ratio of observed deaths to actual deaths) ranged from 0.70 to 1.97.

Eliminating the wide variation in death rates could substantially improve the difference in death rates between black and white VLBW babies. In fact, 25 percent of the disparity would be eliminated if the hospitals with the highest neonatal death rates could do as well as the hospitals with an average neonatal mortality rate.

“This study clearly shows that hospital quality is a big part of the reason that very low birth weight babies who are black have such poor survival rates in New York City,” said Commonwealth Fund Assistant Vice President Anne Beal, M.D. “These findings hold even when controlling for other factors that contribute to differences in infant mortality. In order to save these babies, we need to find out where the delivery of high quality care breaks down and take steps to make improvements at all hospitals; especially those hospitals with the highest neonatal death rates, which often care for more minority infants.”

Researchers reviewed all live births and deaths of infants born in 45 New York City hospitals between January 1996 and December 2001, measuring very low birth weight neonatal mortality rates, or deaths within 28 days after delivery, for the study. They adjusted for outside risks such as prenatal care and the mother's health.