Patient inclusion and data sources
The majority of these results are for patients in England and Wales diagnosed with bowel cancer 1 Apr 2015 – 31 Mar 2016. The exceptions are for 2-year mortality and 18-month stoma rate. Two-year mortality estimates include patients undergoing a major resection between 1 April 2013 and 31 March 2014. 18-month stoma rates include rectal cancer patients undergoing a major resection between 1 April 2012 and 31 March 2015.
The Audit dataset is linked to Hospital Episode Statistics (HES) and Patient Episode Database for Wales (PEDW) at the patient level to obtain further information on patient care and follow-up such as stoma reversal and emergency readmissions in England/Wales, and to the National Radiotherapy Dataset (RTDS) for information on radiotherapy treatment in England.
Data Quality
Data completeness
% of relevant patient group with useable value of data item.
Case ascertainment
Number of patients reported to the Audit as a percentage of the number of patients admitted for the first time to the trust/network with a diagnosis of bowel cancer within the audit period according to HES/PEDW. This can be larger than 100 if more patients are reported to the Audit than identified in HES/PEDW.
7 audit items for risk-adjustment
The per cent of patients with complete data items on all of age, sex, ASA grade, pathological T-stage, pathological N-stage, distant metastases and site of cancer.
Management of all patients
No major resection: too little cancer
Those undergoing a local resection of polypectomy.
No major resection: too much cancer
No excision and reason for no treatment includes advanced stage cancer OR no excision and non-curative intent and metastatic disease.
No major resection: too frail
not in too much cancer group AND no excision and reason for no treatment includes significant co-morbidity OR no excision and performance status 3 or 4.
No major resection: unknown/other reason:
no excision and does not meet any of the above criteria.
Compare trust outcomes
Funnel plots display trust risk-adjusted outcomes for 90-day mortality, 30-day unplanned readmission, 2-year mortality and, for rectal cancer patients, 18-month stoma rate. The funnel regions represent the 95 per cent limit and the 99.8 per cent limit for trusts compared to the national average. Those trusts with results outside the outer (99.8 per cent) limit are considered potential outliers.
Risk adjustment is performed using the seven items listed under Data Quality as well as mode of admission (elective/emergency) and number of co-morbidities according to HES/PEDW, and an interaction between age and distant metastases. Missing values are imputed using Multiple Imputation. The model for two-year mortality additionally includes interactions between follow-up time (0-3 months after surgery vs. 3-24 months after surgery) and all of the risk factors.
A stoma is considered to be reversed if a HES/PEDW record with relevant code is identified with 18 months of the initial surgical procedure.
See FAQs for more details.