Use of Palivizumab May Shorten Infant Hospital Stay
Major Finding: The average length of stay for RSV fell 12.9% after the introduction of palivizumab, versus a decrease of 3.4% for other causes of infant hospitalization.
Data Source: Retrospective cross-section comparison of two time periods.
Disclosures: Dr. Racine reported no conflicts or external study support.
VANCOUVER, B.C. — The introduction of palivizumab as a preventative treatment for respiratory syncytial virus appears to be associated with a shorter length of hospital stay for the disease, one California study showed.
Hospital charges for respiratory syncytial virus (RSV) also increased at a slower pace than for other causes of infant hospitalization, according to a retrospective analysis of California discharges among 3,443,918 infants less than 1 year of age.
The data provide real-world evidence about the impact of palivizumab (Synagis) in the community since its approval in 1998 based on one company-sponsored study, said Dr. Andrew Racine, chief of the general pediatrics section at Albert Einstein College of Medicine in New York City<
“This is important for the following reason: The U.S. sales of palivizumab have gone from about $225 million dollars in 1998 to over $1.5 billion dollars in 2007,” he said. “We're using a lot of this; we might as well know if it's effective.”
Palivizumab costs about $900 a dose, with most at-risk children receiving five doses as prophylaxis. There is no treatment for RSV.
Dr. Racine cautioned that the data are from a single state and were not stratified by risk categories for RSV. In addition, the findings were based on an intent-to-treat analysis and thus may not reflect whether patients actually received the medication. There are plans to link the birth certificate to the hospitalization and to identify gestational age and congenital illnesses.
The researchers used data from the California Patient Discharge Database and individual level hospitalization records to compare length of stay and hospitalization costs among infants less than 1 year of age during two time periods—before (1995-1997) and after (2005-2007) palivizumab.
The mean length of stay for RSV hospitalizations fell 12.9% from 3.95 days before palivizumab to 3.43 days after the drug. This compares with a decrease of 3.4% for non-RSV hospitalizations, which went from 3.2 days to 3.09. The difference was statistically significant at a P value less than .001, Dr. Racine said at the meeting.
Median hospital charges in constant 2007 dollars for an RSV diagnosis increased 20.1% from $16,060 to $19,390 after palivizumab, while non-RSV charges rose 58.6% from $11,901 to $18,857 over the two periods. Again the difference was significant at a P value equal to .001.
Session moderator Dr. Esther Chung, a pediatrician with Thomas Jefferson University Hospitals in Philadelphia, suggested that factors besides length of stay could be driving down RSV hospitalization costs.
Dr. Racine said that lower use of albuterol, corticosteroids, and imaging studies also may have occurred during the second time period, but that these data were not examined and that his own “heartbreaking” experience suggests that these practices continue.
“There are a lot of things we are still doing to these children with this condition that are completely unnecessary and costly,” he said.
A study led by Dr. Caroline B. Hall, whose earlier work led to the approval of palivizumab, reported that only 3% of 355 outpatients with confirmed RSV infection received an RSV diagnosis, with 20% of these children diagnosed with bronchiolitis. Dr. Hall and her associates estimated that RSV infection results in 1 of 334 hospitalizations among children under the age of 5 years (N. Engl. J. Med. 2009;360:588-98).