U.S. News & World Report has ranked hospitals in pediatrics since launching the annual “Best Hospitals” rankings in 1990. Until 2007, however, the pediatric rankings were based solely on reputation, determined by an annual survey of board-certified pediatricians and adolescentmedicine specialists.<br><br>The obstacle to data-driven rankings was the absence of quantitative measures comparable to those used to rank most Best Hospitals specialties. For example, Medicare data (i.e., MedPAR) are used to determine mortality in 12 adult specialties. No such large pediatric mortality database was or currently is available. (A relatively small number of children, under narrowly defined conditions of eligibility, receive care under Medicare because of legislatively mandated changes in coverage over time.) Reliable structural measures were also absent. Available data sources generally reported volume, advanced technologies, and patient services across a hospital and did not break out pediatric-specific information.