The results, researchers say, point to an opportunity to improve how children's hospitals approach the use of antibiotics - and, with hope, help combat the problem of antibiotic resistance. Antibiotics are deployed against bacterial infections.
But when the drugs are used too widely or misused, bacteria can become resistant to the medications. Multi drug-resistant bacteria are a growing problem in hospitals, which have seen the rise of "superbug" infections such as methicillin-resistant Staphylococcus aureus (MRSA).
Drug-resistant infections account for billions of dollars in additional healthcare costs annually, according to the Institute of Medicine.
In response to the issue, professional groups like the Infectious Diseases Society of American (IDSA) have called on hospitals to develop programs aimed at more judicious use of antibiotics.
One ISDA report estimated that half of all antibiotic use in hospitals is unnecessary. Prior research has also found that U.S. hospitals vary substantially in their antibiotic use, but little has been known about the nation's children's hospitals.
For the new study, published in the journal Pediatrics, investigators looked at antibiotic prescribing in 2008 at 40 children's hospitals nationwide. Based on records from more than 550,000 children discharged during that year, 60 percent received at least one antibiotic during their stay.
But that rate varied widely from hospital to hospital, ranging from 38 percent to 72 percent. And the researchers could not find specific factors that explained the variance, such as high-prescribing hospitals having sicker patients or a higher number of surgeries that would require preventive use of antibiotics.
"Even when we adjusted for those factors, we still saw a really wide range in antibiotic use," said lead researcher Dr. Jeffrey S. Gerber, of Children's Hospital of Philadelphia.
"It's surprising how significant (the variation) is, considering they're all children's hospitals," Gerber noted in an interview. The reasons for the differences remain unclear for now, according to Gerber.
But he said these findings provide an "important call" to identify the factors that lead some hospitals to prescribe antibiotics more often than others do. It's not possible to tell from this study whether the high-prescribing children's hospitals were giving antibiotics too often, or whether the low-prescribing ones were underusing the drugs, Gerber said.
However, he and his colleagues note in the report, it is more likely that some hospitals excessively prescribe antibiotics.
Gerber did point out that most U.S. children's hospitals do not yet have the "antimicrobial stewardship programs" recommended by the IDSA and other groups for driving down inappropriate antibiotic use. It's possible that wider implementation of such programs would reduce antibiotic use at some hospitals, Gerber noted.
He said future studies need to look in more detail at the factors driving antibiotic use at children's hospitals, and how those prescribing practices may ultimately affect children's outcomes.