The information on surgeon outcomes was derived from data on patients diagnosed between 1 April 2011 and 31 March 2012. For most patients, the Audit had information on all aspects of their disease and the care received. This data had been used to produce the National Oesophago-Gastric Cancer Audit 2013 Annual Report.
For O-G cancer patients undergoing curative surgery, the case-ascertainment rate in the original data collection was very high at 89% (see the NOGCA 2013 Annual Report for more details). Nonetheless, for this surgeon-level outcome report, hospitals were able to notify the Audit of additional patients. However, it was not possible to collect the complete dataset on these patients.
Data on surgeon GMC codes were collected retrospectively in April-May 2013 for all curative operations. The Audit provided NHS trusts with the NHS number and other details of patients who received surgical treatment, and the NHS trusts then assigned surgeon GMC codes to these patients.