MD Professor of Colorectal Surgery and Chair Colorectal Cancer Clinical Reference Group Michel P Coleman FFPH Professor of Epidemiology and Vital Statistics

Objectives: To assess the variation in risk-adjusted 30-day post-operative mortality for colorectal cancer patients between Hospital Trusts within the English NHS. Setting: All providers of major colorectal cancer surgery within the English NHS Participants: All 160,920 individuals who underwent a major resection for a colorectal cancer diagnosed between 1998 and 2006 in the English NHS Main outcome measures: National patterns of 30-day post-operative mortality were examined and logistic binary regression used to study factors associated with death within 30 days of surgery. Funnel plots were used to show variation between Trusts in risk-adjusted mortality. Results: Overall 30-day mortality was 6.7% but decreased over time from 6.8% in 1998 to 5.8% in 2006. The biggest reduction in mortality was seen in 2005 and 2006. Post-operative mortality increased with age (15.0% (95%CI 14.1-15.9%) for those aged over 80), co-morbidity (24.2% (95%CI 22.0-26.5) for those with a Charlson co-morbidity score of 3 or more), stage of disease (9.9% (95%CI 9.3-10.6%) for Dukes' D patients), socioeconomic deprivation (7.8% (95%CI 7.2-8.4%) for residents of the most deprived quintile) and operative urgency (14.9% (95%CI 14.2-15.7%) for patients undergoing emergency resection). Risk-adjusted control charts demonstrated that one Trust had consistently significantly better outcomes and three significantly worse outcomes than the population mean. Conclusions: Significant variation in 30-day post-operative mortality following major colorectal cancer surgery existed between NHS hospitals in England throughout the period 1998 to 2006. Understanding the underlying causes of this variation between surgical providers will make it possible to identify and spread best practice, improve outcomes and, ultimately, reduce 30-day post-operative mortality following colorectal cancer surgery 4 What this paper adds What is already known about this subject • There is increasing demand for the NHS to publish clinical outcomes, such as post-operative mortality, to inform patient choice and improve standards. • To be robust and informative such figures must take into account differences in the casemix of patient populations, hospital surgical workloads and be population-based. • Previously such data have not been available. What are the new findings? • This study has demonstrated a method via which it is possible to assess variation in the risk-adjusted 30-day post-operative mortality for colorectal cancer patients across all hospital trusts within the English NHS. • The study has demonstrated significant variation in this outcome between hospital Trusts. How might it impact on clinical practice in the foreseeable future? • Understanding the underlying causes that have lead to …