Author Contributions: As principal investigator of the study, Dr Spiro had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Spiro, Arnold, Baker, Shapiro.
Acquisition of data: Tay.
Analysis and interpretation of data: Spiro, Tay, Dziura, Shapiro.
Drafting of the manuscript: Spiro, Tay.
Critical revision of the manuscript for important intellectual content: Spiro, Tay, Arnold, Dziura, Baker, Shapiro.
Statistical analysis: Spiro, Dziura, Shapiro.
Obtained funding: Spiro, Dziura, Shapiro.
Administrative, technical, or material support: Tay.
Study supervision: Spiro, Baker, Shapiro.
Financial Disclosures: None reported.
Funding/Support: This work was supported in part by grant AI01703 from the National Institutes of Health, grant M01-RR00125 from the General Clinical Research Center, Yale University School of Medicine, and the Friends of Yale-New Haven Children's Hospital, who provided material support for this research.
Role of the Sponsor: The funding organizations played no role in the design, conduct, analysis, or interpretation of the research or in any aspect of preparation or approval of the manuscript.
Acknowledgment: We thank John Leventhal, MD, Department of Pediatrics, Yale University School of Medicine, for his careful review of the manuscript. Dr Leventhal received no compensation for his contribution.