Accepted for Publication: September 11, 2014.
Published Online: November 24, 2014. doi:10.1001/jamapediatrics.2014.2042.
Study concept and design: All authors.
Acquisition, analysis, or interpretation of data: Anzman-Frasca, Halmo, Economos. Drafting of the manuscript: Anzman-Frasca.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Anzman-Frasca.
Obtained funding: Dolan, Economos.
Administrative, technical, or material support: Djang, Halmo.
Study supervision: Anzman-Frasca, Economos.
Conflict of Interest Disclosures: None reported.
Funding/Support: This study was supported by the JPB Foundation and the Robert Wood Johnson Foundation and included support for design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation of the manuscript.
Role of the Funder/Sponsor: The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and the decision to submit the manuscript for publication.
Additional Contributions: Sisi Wang, MPH, Yale School of Public Health, contributed to data cleaning and management; Bethany Bray, PhD, and Megan Schuler, PhD, Methodology Center, Pennsylvania State University, provided feedback on the propensity score methods; and the individuals at the school district helped make data abstraction and analysis possible.