Accepted for Publication: July 14, 2012.
Author Contributions: Drs Lloyd-Lavery and Taghipour 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: Wojnarowska and Taghipour. Acquisition of data: Lloyd-Lavery and Taghipour. Analysis and interpretation of data: Lloyd-Lavery, Chi, Wojnarowska, and Taghipour. Drafting of the manuscript: Lloyd-Lavery, Chi, and Taghipour. Critical revision of the manuscript for important intellectual content: Lloyd-Lavery, Chi, Wojnarowska, and Taghipour. Statistical analysis: Chi. Obtained funding: Taghipour. Administrative, technical, or material support: Lloyd-Lavery and Taghipour. Study supervision: Wojnarowska and Taghipour.
Conflict of Interest Disclosures: None reported.
Funding/Support: This study was supported in part by the Dunhill Medical Trust.
Role of the Sponsors: The Dunhill Medical Trust had no role in the design and conduct of the study; in the collection, analysis, and interpretation of data; or in the preparation, review, or approval of the manuscript.
Additional Contributions: Richard Mayon-White, MBBS, FRCP, FFPH, of the Department of Primary Health Care Sciences, University of Oxford, provided epidemiological advice.