Study: Hospital Volume Tied to Care for Premature Babies
Infants born very prematurely are up to twice as likely to survive if treated at a high-volume neonatal intensive care unit in a large hospital, according to a study published Thursday in the New England Journal of Medicine, the AP/Chicago Tribune reports (Stobbe, AP/Chicago Tribune, 5/23).
The study, conducted by researchers from Stanford University, the University of California-San Francisco and VA Palo Alto Health Care System, examined data from 48,000 infants born in California weighing between one and three pounds at birth from 1991 to 2000 (Allday, San Francisco Chronicle, 5/24).
The study excluded newborns who weighed less than 1.1 pounds or had life-threatening congenital defects (Feder Ostrov, San Jose Mercury News, 5/24).
According to the study, infants receiving care in high-level NICUs -- known as Level 3 NICUs -- with more than 100 premature patients treated annually had the lowest mortality rate at 18%. Premature infants in high-level units that saw between 50 and 100 cases annually had a mortality rate of about 20%. As the level designation and patient volume decreased, the mortality rate increased, the study found.
Mid-level NICU units, which lack ventilators and neonatal surgeons, that treated fewer than 10 infants per year had a premature infant mortality rate of about 32%, according to researchers. The effect was consistent across race, size and gender differences (AP/Chicago Tribune, 5/24).
Very premature infants accounted for 1.4% of births and 51% of all newborn deaths from 1991 to 2000 (San Jose Mercury News, 5/24).
Researchers recommended that NICUs in the same regions be consolidated to form larger units with greater volume, which they estimate could prevent 21% of deaths among premature infants (AP/Chicago Tribune, 5/23).
However, smaller community hospitals might be unlikely to close NICUs because they are lucrative and useful for marketing and recruiting top obstetricians (San Francisco Chronicle, 5/24).
In addition, some rural area residents have limited access to larger hospitals and would be harmed by consolidation, according to Debby Rogers, vice president of quality and emergency services for the California Hospital Association. She said, "Is that lower-level NICU ... better than no NICU at all? The answer to that ... is always going to be yes" (San Jose Mercury News, 5/24).
Lead researcher Ciaran Phibbs of Stanford University said that argument was considered when making a recommendation. However, researchers found that 92% of premature births in 2000 occurred in urban areas with more than 100 such cases each year (AP/Chicago Tribune, 5/23). Very few premature births happen so quickly that the mother could not be transported to a busier, more advanced NICU, according to researchers (San Francisco Chronicle, 5/24).
Phibbs said, "We're not saying you shouldn't have NICUs in community hospitals. It's just that they should be dealing with the moderate-risk infants, not the high-risk infants."
Aaron Caughey, a study co-author from the University of California, said, "If your clinical group takes care of a lot of patients year after year, you start to identify trends you would miss with less volume. Experience lends knowledge and wisdom, to not just physicians but the entire team" (AP/Chicago Tribune, 5/23).
Phibbs said, "The community hospitals may be pushing the envelope," adding, "What we've continued to see is not only more hospitals opening [NICUs], but these hospitals trying to care for more and more complex cases and more and more critically ill infants" (San Francisco Chronicle, 5/24).