Submitted for Publication: March 19, 2013; final revision received May 28, 2013; accepted June 10, 2013.
Published Online: November 14, 2013. doi:10.1001/jamaophthalmol.2013.5696.
Study concept and design: Keenan, M. J. Goldacre.
Acquisition of data: M. J. Goldacre.
Analysis and interpretation of data: All authors.
Drafting of the manuscript: Keenan, M. J. Goldacre.
Critical revision of the manuscript for important intellectual content: R. Goldacre, M. J. Goldacre.
Statistical analysis: R. Goldacre, M. J. Goldacre.
Obtained funding: M. J. Goldacre.
Study supervision: M. J. Goldacre.
Conflict of Interest Disclosures: None reported.
Funding/Support: This study was supported by the English National Institute for Health Research to analyze the linked data and by Fight For Sight through a clinical fellowship (Dr Keenan). No other disclosures were reported.
Role of the Sponsor: English National Institute for Health Research and Fight For Sight had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Additional Contributions: Leicester Gill, BSc, Myfanwy Griffith, MSc, Matt Davidson, BSc, and David Yeates, PhD, built the linked data files and associated analytical software.