Title: Constructing the entire care pathway of bowel cancer patients undergoing emergency surgery to improve their quality of care
Funder: Department of Health and Social Care

Abstract: Background: Over 30,000 people are diagnosed with bowel cancer each year in England alone. One in five patients is diagnosed after being admitted to hospital in an emergency. In most of these patients, their cancer has grown so large that it is blocking their bowel and this is a life-threatening situation. The main treatment for these patients is emergency surgery, but the surgery itself is high risk with one in eight patients dying from the procedure. _x000D_ _x000D_ There are national guidelines on the care these patients should receive, for example having a consultant in the operating theatre, getting to theatre quickly, and being taken to intensive care after their operation. There is, however, only limited evidence that following these guidelines improves patient survival or reduces the chance of complications. The aim of this project is to discover which aspects of care affect patient outcomes. Our findings will help hospitals and clinicians to improve patient care, and will add to the evidence for new guidelines. _x000D_ _x000D_ Data: Data is collected on bowel cancer patients having emergency surgery in national clinical datasets. These datasets collect details about the patients, their cancer, the care they receive before, during and after surgery, and the outcomes of their treatment. But the information is collected in several separate datasets. All of these datasets need to be linked so that we can find out which parts of care affect patient outcomes._x000D_ _x000D_ Planned work:_x000D_ 1. Linking several databases together is not straightforward. Information has to be passed between organisations, with a risk to the security of this information. We will assess a new approach to linking databases, which makes use of links that have already been made between each National Clinical Audit and a database of all admissions to hospital, the Hospital Episode Statistics data. If this new approach proves to be valid it will offer a potential new way of linking databases in which no additional transfer of information between organisations is needed._x000D_ 2. Methods are needed to link records in the different databases that belong to the same patient. The methods used at the moment look for an exact match on patient identifiers such as NHS number, date of birth and postcode. Small data entry errors on just one identifier can mean that data belonging to the same patient cannot be linked. We aim to improve this approach by making use of a wider set of information to link the databases, and allowing records which match on most information but have small differences on some items to be linked._x000D_ 3. Some information, such as whether the cancer has spread, and whether the patient went to intensive care, is collected in more than one database. This part of the work is to develop methods to bring together the information from different sources and make sure the most accurate information is used._x000D_ 4. With the linked databases we will study which aspects of patient care are the most important for improving survival and reducing complications in bowel cancer patients having emergency surgery._x000D_ 5. The methods chosen to link the databases may give slightly different results. We will assess how much the answers to our research question differ when we use the different methods. If the findings are very similar for the different methods then we will know that our findings are reliable.

Lay abstract: Background: Bowel cancer is common with over 30,000 new cases per year in England. It has a high rate of acute presentation with around one in five patients diagnosed after an emergency hospital admission. Emergency surgery to remove the tumour is usually necessary because the patient’s condition is life threatening. However, it is a high-risk procedure, with one in eight patients dying within 90 days._x000D_ _x000D_ There are guidelines recommending the care that should be given to patients having emergency bowel surgery, including having a consultant anaesthetist and surgeon present in theatre, and transfer of patients from theatre to critical care. The evidence supporting these guidelines is limited. National clinical datasets collect information on bowel cancer patients, their tumour pathology, the care received, and the outcomes of care, but the information is collected in several separate datasets._x000D_ _x000D_ By linking these national datasets together the entire care pathway can be constructed so that the factors which have the greatest impact on the outcomes of care can be identified. In order to do this, methodology must be developed to minimise bias from data linkage errors, incomplete capture of patients in each dataset, and confounding due to patient selection._x000D_ _x000D_ Aims and anticipated impact: The aim of this project is to identify which processes of care reduce mortality and complications in bowel cancer patients undergoing emergency surgery. In order to do this, methods will be developed to minimise bias from data linkage errors, incomplete capture of patients into each audit, and confounding due to patient selection. This will ensure that funding and efforts are directed towards the interventions with the greatest impact on patient outcomes. _x000D_ _x000D_ Research plan: Firstly, we will develop methods for linking patients across datasets by improving the existing techniques used to link national datasets in order to reduce linkage errors. This will include developing probabilistic linkage methods, and assessing the benefit of using additional “indirect identifiers” to link datasets._x000D_ _x000D_ Secondly, we will evaluate a new “spine” approach to data linkage that makes use of existing linkages between Hospital Episode Statistics data (HES) and national clinical datasets so that no further data linkages are required. This approach is potentially more secure and efficient than linking each dataset in turn, but will miss patients not identified in HES, potentially introducing selection bias. _x000D_ _x000D_ Third, we will develop coding strategies to deal with multiple sources of the same information across datasets, some of which will be conflicting. _x000D_ _x000D_ Finally, we will identify the components of care which have the greatest impact on patient outcomes, using carefully developed risk-adjustment methods to deal with confounding by patient selection. We will assess the sensitivity of our findings to the methods that we have developed.

Research activity codes: 8.1 ORGANISATION AND DELIVERY OF SERVICES
Health categories: CANCER AND NEOPLASMS