Submitted for Publication: November 27, 2011; final revision received February 20, 2012; accepted February 29, 2012.
Author Contributions: Drs Berg, Jonsson, and Engström, had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Berg, Jonsson, Kanerva, Hultcrantz, and Engström. Acquisition of data: Berg, Jonsson, Kanerva, and Engström. Analysis and interpretation of data: Berg, Bylund, Marsk, Jonsson, and Engström. Drafting of the manuscript: Berg and Jonsson. Critical revision of the manuscript for important intellectual content: Berg, Bylund, Marsk, Jonsson, Kanerva, Hultcrantz, and Engström. Obtained funding: Jonsson and Engström. Administrative, technical, and material support: Berg, Jonsson, and Kanerva. Study supervision: Jonsson.
Financial Disclosure: None reported.
Funding/Support: This study was supported by Uppsala University and Acta Otolaryngologica Foundation.
Additional Contributions: Anne Pitkäranta, MD, PhD, Anna Stjernquist-Desatnik, MD, PhD, and Sara Axelsson, MD, provided help with the study. Nermin Hadziosmanovic (Biostatistician, Uppsala Clinical Research Centre) provided statistical expertise.