How much variation in use is too much?

Vancomycin is indicated for the treatment of serious or severe infections caused by susceptible strains of methicillin-resistant (beta-lactam-resistant) staphylococci.  Because of concerns about the development of drug-resistant bacteria, recommendations to prevent the spread of vancomycin resistance have been in place since 1995 and include guidelines for inpatient pediatric use of vancomycin.  With such guidelines in place, it is of special interest to compare inpatient pediatric vancomycin administration across hospitals.

Our recent publication, “Pediatric Vancomycin Use in 421 Hospitals in the United States 2008” published in PLOS ONE on 8/16/2012 (Lasky T, Greenspan J, Ernst FR, and Gonzalez L), compares vancomycin use in all pediatric hospitalizations (hospitalizations of children under age 18) in 421 hospitals in the Premier database.

Key Findings

• Vancomycin was administered to children at 374 hospitals in the Premier hospital database.
• Another 47 hospitals with 17,271 pediatric hospitalizations (13,233 under age 2) reported no vancomycin use during 2008.
• The number of pediatric hospitalizations with vancomycin use ranged from 0 to 1225 at individual hospitals.
• Most hospitals (221) had fewer than 10 pediatric hospitalizations with vancomycin use in the study period.
• 21 hospitals (5.6% of hospitals) each had over 200 hospitalizations with vancomycin use, and together, accounted for more than 50% of the pediatric hospitalizations with vancomycin use.
• Percentage of hospitalizations with vancomycin use ranged up to 33.3% when hospitals with few pediatric hospitalizations were kept in the sample, the high percenetages being an artifact of the small number of hospitalizations in the denominator. For this reason, percentage, by itself, may not be a useful indicator in small hospitals.
• In hospitals with more than 100 pediatric hospitalizations with vancomycin use, the percentage with vancomycin use ranged from 1.26 to 12.90, a 10 fold range in the prevalence of vancomycin use.
• Our stratified analyses and logistic modeling showed variation in vancomycin use by individual hospital that was not explained by hospital or patient characteristics including: bed size, teaching status, region of the country, rural or urban geography, and patient sex, race, APR-DRG risk of mortality and APR-DRG severity of illness.

For Discussion and Further Investigation

Until recently, few studies have compared pediatric antibiotic use across large numbers of hospitals or geography, and it was not possible to assess variation in use across institutions. Hospital variation in care of adults has been studied for several decades, much of it made possible by large Medicare claims databases. With the availability of aggregated data for pediatric hospitalizations we can begin describing and attempting to understand variation in pediatric practice. This first study of hospital variation in pediatric vancomycin use raises questions for further research.