About the Authors

Robert L Davis

To whom correspondence should be addressed. E-mail: robert.l.davis@kp.org

Affiliations Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, United States of America, Department of Epidemiology, University of Washington School of Public Health, Seattle, Washington, United States of America

Jeffrey Wright

Affiliations Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, United States of America, Child Health Institute, University of Washington School of Medicine, Seattle, Washington, United States of America

Francie Chalmers

Affiliation Skagit Pediatrics Medical Group, Skagit Valley, Washington, United States of America

Linda Levenson

Affiliations Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, United States of America, Child Health Institute, University of Washington School of Medicine, Seattle, Washington, United States of America

Julie C Brown

Affiliations Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, United States of America, Child Health Institute, University of Washington School of Medicine, Seattle, Washington, United States of America

Paula Lozano

Affiliations Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, United States of America, Child Health Institute, University of Washington School of Medicine, Seattle, Washington, United States of America

Dimitri A Christakis

Affiliations Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, United States of America, Child Health Institute, University of Washington School of Medicine, Seattle, Washington, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

RLD conceived and designed the study, was involved in data acquisition and interpretation, drafted the article and had final approval. JW helped design the study and acquire the data; he helped revise the article for content, and gave final approval. FC helped acquire and interpret the data and revise the article for content, and gave final approval. LL helped acquire the data and interpret the results and revise the article for content, and gave final approval. JCB helped acquire and interpret the data, made substantial revisions to the article drafts, and gave final approval for publication. PL helped design the study, helped with data acquisition and interpretation, made revisions to article drafts, and gave final approval for publication. DAC was involved in conception and design of the study, was involved with data acquisition and interpretation, helped revise the article, and gave final approval for publication.