Accepted for Publication: August 12, 2011.
Published Online: November 21, 2011. doi:10.1001/archsurg.2011.311
Author Contributions:Study concept and design: Mamidanna, Burns, Hanna, and Faiz. Acquisition of data: Burns, Bottle, and Aylin. Analysis and interpretation of data: Mamidanna, Bottle, and Stonell. Drafting of the manuscript: Mamidanna. Critical revision of the manuscript for important intellectual content: Burns, Bottle, Aylin, Stonell, Hanna, and Faiz. Statistical analysis: Bottle and Faiz. Administrative, technical, and material support: Mamidanna. Study supervision: Aylin and Faiz.
Financial Disclosure: The Dr Foster Unit at Imperial College is affiliated with the Centre for Patient Safety and Service Quality at Imperial College Healthcare NHS Trust, which is funded by the National Institute for Health Research.
Funding/Support: The Dr Foster Unit is largely funded by a research grant from Dr Foster Intelligence (an independent health service research organization).
Previous Presentations: The abstract was presented at The Association of Coloproctology of Great Britain and Ireland meeting; June 22, 2011; Birmingham, England, and the Tripartite Colorectal Meeting; July 4, 2011; Cairns, Australia.
Additional Information: We have ethics approval under Section 251 (formerly Section 60) granted by the National Information Governance Board for Health and Social Care (formerly the Patient Information Advisory Group). We have approval for using these data for research from the South East Research Ethics Committee.
Additional Contributions: We are grateful for support from the National Institute for Health Research Biomedical Research Centre funding scheme.