Thousands of sickly newborns could be saved each year if officials closed some of the nation's smaller neonatal intensive care units, according to a new study that suggests larger hospitals are better able to treat the infants.
Extremely premature babies were up to twice as likely to survive when treated at a busy, advanced-care center instead of one of the many community hospitals that have opened NICUs in recent years.
Even among the most advanced centers, those that handled the most babies had the best survival records, said Ciaran Phibbs, lead author of the study appearing in Thursday's New England Journal of Medicine.
"Size really matters," said Phibbs, a Stanford University health economist.
Earlier studies found conflicting results when reviewing the relationship between neonatal deaths and number of infants treated by a hospital. But Phibbs' study is the largest and best of its kind, experts said.
"It's quite persuasive," said Dr. David Goodman, a Dartmouth Medical School neonatal care specialist who was not involved in the study.
The study reviewed nearly 48,000 premature births and fetal deaths in California from 1991 through 2000, using birth and death certificates and hospital records. Researchers focused on babies with very low birth weights of 1 to 3 pounds.
California's top neonatal intensive care units -- called Level 3 NICUs -- offer the full range of neonatal care and surgery. They had the best survival rates. Those that treated more than 100 premature babies each year had the lowest death rate -- about 18 per cent. In similar facilities that treated 50 to 100 infants a year, about 20 per cent died.
The trend continued in less comprehensive neonatal units. The lower the level of care and the smaller the number of babies, the higher the death rate. In Level 2 NICUs that saw 10 or fewer tiny babies a year, more than 31 per cent died.
The effect was seen across race and size differences in the infants studied, and in both genders.
Based on the results, researchers estimated that consolidating intensive care units could prevent 21 per cent of deaths among especially small infants.
Why the difference? Hospitals with busy neonatal units also have advanced obstetrics care, including around-the-clock anesthesiology and other services to quickly handle emergencies, Phibbs said. They also have more practice.
"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," said Dr. Aaron Caughey, a study co-author from the University of California at San Francisco.
Phibbs said the issue is apparent in metropolitan areas such as Stockton, Calif., which has 100 to 150 extremely premature births each year. Most of those cases are distributed among three hospital NICUs, all within a few miles of each other.
"It's certainly feasible there, if they worked out the agreement, for all those high-risk deliveries to be done in one place," he said.
Historically, the expertise and technology needed to run an NICU have been scarce, and care was concentrated at academic medical centers. In some states, laws or regulations confined services to a few hospitals.
But in the last 20 years, the number of NICUs boomed -- from 578 in 1985 to 838 in 2004, one industry survey found. In California, the number rose from 156 in 1991 to 168 in 2000.
One reason is more doctors specializing in neonatal care, Goodman said. Hospitals have also recognized that such care can be lucrative. Virtually all NICU patients have public or private insurance, and hospitals charge a lot for this kind of care. "NICUs make money for hospitals," Caughey said.
Operating an NICU is a source of pride -- and a focus of marketing -- for hospitals interested in attracting obstetrics business, experts said.
Marketing materials are some of the only information expectant parents have available when choosing a birthing center, because hospital-specific infant mortality data is not available to the public.
"They may never know they're potentially putting their kids at risk" by choosing hospitals with lower-volume, less-comprehensive neonatal care, said Dr. Kevin Schulman, director of the health sector management program at Duke University's business school.
Hospital industry officials acknowledged that such information is not available, but new Web sites such as http://www.hospitalcompare.hhs.gov and http://www.calhospitalcompare.org may help.
Debby Rogers, vice president of quality and emergency services for the California Hospital Association, said closing NICUs carries some risk.
Residents of some rural areas have limited access to advanced medical services, and it's better for them to have limited NICU care than no such care at all, she said.
Phibbs said his team considered that argument, and found 92 per cent of the births in 2000 occurred in urban areas with more than 100 such deliveries each year.
