Accepted for Publication: January 7, 2015.
Published Online: March 2, 2015. doi:10.1001/jamapediatrics.2015.25.
Study concept and design: Saari, Harju, Mäkitie, Dunkel, Sankilampi.
Acquisition, analysis, or interpretation of data: Saari, Harju, Mäkitie, Saha, Dunkel, Sankilampi.
Drafting of the manuscript: Saari, Harju, Mäkitie, Dunkel, Sankilampi.
Critical revision of the manuscript for important intellectual content: Mäkitie, Saha, Dunkel, Sankilampi.
Statistical analysis: Saari, Harju, Sankilampi.
Obtained funding: Dunkel, Sankilampi.
Administrative, technical, or material support: Mäkitie, Dunkel.
Study supervision: Mäkitie, Saha, Dunkel, Sankilampi.
Conflict of Interest Disclosures: None reported.
Funding/Support: This study was supported by the Finnish Funding Agency for Technology (Drs Saari, Sankilampi, Dunkel, and Harju), the National Graduate School of Clinical Investigation (Dr Saari), Kuopio University Hospital (Dr Sankilampi), the Sigrid Juselius Foundation (Dr Mäkitie), the Foundation for Pediatric Research (Dr Mäkitie), the Academy of Finland (Dr Mäkitie), and the Folkhälsan Research Foundation (Dr Mäkitie).
Role of the Funder/Sponsor: The funders 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 decision to submit the manuscript for publication.
Additional Contributions: Marja-Leena Lamidi, MSc, University of Eastern Finland, assisted with statistics and did not receive financial compensation.