NBOCA FAQs

The National Bowel Cancer Audit (NBOCA) is a mandatory national audit that has been in place since 2010. Its purpose is to measure the quality of care and patient outcomes for individuals with a new diagnosis of bowel cancer in NHS hospitals throughout England and Wales. The goal is to ultimately improve the quality of care provided. The audit is commissioned by the Healthcare Quality Improvement Partnership (HQIP), funded by NHS England and the Welsh Government, and conducted by the National Cancer Audit Collaborating Centre (NATCAN), which is part of the Royal College of Surgeons of England.

The audit involves a wide range of professionals and organisations that collaborate to ensure its effectiveness. The core group is the NBOCA Project Team, which works in close consultation with its own Clinical Advisory Group and a Patient & Public Involvement Forum to integrate expert and patient perspectives.

Beyond these groups, the audit is a partnership between several key entities. The Healthcare Quality Improvement Partnership (HQIP) commissions the audit, while funding is provided by NHS England and the Welsh Government. The National Cancer Audit Collaborating Centre (NATCAN), which is part of the Royal College of Surgeons of England’s Clinical Effectiveness Unit, is responsible for delivering the audit and managing the data.

NATCAN is part of the Clinical Effectiveness Unit (CEU) in London – a collaboration between the Royal College of Surgeons of England (RCSEng) and the London School of Hygiene & Tropical Medicine (LSHTM). The CEU brings together the best clinicians (the doctors on the front line against cancer who know what the problems are) and the best academics (the data scientists and statisticians who can interpret the results generated by the data in the most effective way). It has already been working on cancer audits for more than 15 years.

The National Cancer Audit Collaborating Centre (NATCAN) is a new national centre of excellence which will shine a spotlight on the care and treatment of patients who are diagnosed with cancer in England and Wales. The Healthcare Quality Improvement Partnership (HQIP), on behalf of NHS England and the Welsh Government, has commissioned the development and establishment of NATCAN, which is part of the National Clinical Audit and Patient Outcomes Programme (NCAPOP). It aims to:

Stimulate improvements in cancer detection, treatment and outcomes including survival

Provide regular and timely evidence to cancer services of where patterns of care in England and Wales vary

Support NHS services to identify the reasons for the variation in care in order to guide quality improvement initiatives

NATCAN delivers six new national cancer audits:

• National Audit of Primary Breast Cancer (NaoPri)
• National Audit of Metastatic Breast Cancer (NaoMe)
• National Ovarian Cancer Audit (NOCA)
• National Pancreatic Cancer Audit (NPaCA)
• National Non-Hodgkin Lymphoma Audit (NNHLA)
• National Kidney Cancer Audit (NKCA)

The following ‘existing’ national cancer audits moved into NATCAN during 2023

National Lung Cancer Audit (NLCA)

National Prostate Cancer Audit (NPCA)

National Bowel Cancer Audit (NBOCA)

National Oesophago-Gastric Cancer Audit [NOGCA])

Work on setting up the new centre began on October 1 2022. NATCAN is funded by NHS England and the Welsh Government, with £5.4m for an initial period of three years.

NATCAN is part of the Clinical Effectiveness Unit (CEU) in London – a partnership between the Royal College of Surgeons of England (RCSEng) and the London School of Hygiene & Tropical Medicine (LSHTM). 

NPCA, NBOCA, NOGCA and NLCA have now moved into NATCAN bringing all cancer audits together under one umbrella for the first time. The aim is to deliver closer collaboration and better results, sharing learning and best practice.

NATCAN is all about effective collaboration. Each audit is led by a multidisciplinary team of clinical experts and senior academics to ensure that we ask the right questions about cancer care and treatment, and then use the right methods to answer those questions. NATCAN collaborates closely with all relevant stakeholders to inform the quality improvement (QI) priorities and goals of each audit. That includes professional groups, patient charities and patients.

In this way, the new audits are produced to the same high standard as those that the CEU has run for years, maintaining the standards of excellence the CEU is renowned for.

The design and delivery of the audits in NATCAN has been informed by our experience of delivering national audits in the Clinical Effectiveness Unit, built up since its inception in 1998. Key features of all audit projects within the CEU include:

• Close clinical-methodological collaboration
• Use of national existing linked datasets as much as possible
• Close collaboration with data providers in England (National Disease Registration Service [NDRS], NHS Digital [NHSD]) and Wales (Wales Cancer Network [WCN], Public Health Wales [PHW])
• A clinical epidemiological approach, informing quality improvement activities.
• “Audit” informed by “research”.

All these features will support NATCAN’s focus on the three “Rs”, ensuring that all its activities are clinically relevant, methodologically robust, and technically rigorous.

Each individual cancer audit is jointly led by two clinical leads, representing the most relevant professional organisations, and senior academics with a track record in health services research, statistics, data science and clinical epidemiology, affiliated to the London School of Hygiene and Tropical Medicine.

In addition, each audit will have a clinical fellow, who contributes to all aspects of the audits, reinforcing the audits’ clinical orientation and contributing to capacity building.

The delivery of the audit is coordinated by an audit manager who is supported by NATCAN’s wider infrastructure. Data scientists with experience in data management and statistics, and methodologists with experience in performance assessment and QI, work across audits.

This organisation creates “critical mass” and an audit capacity that is able to respond to the requirements of the funders (NHS England and Welsh Government), and to the wider stakeholder “family”.

In order to reduce the burden on hospital staff, the audits in NATCAN do not ‘collect’ clinical data which aligns with HQIP’s Guidance for Data Burden Reduction. The cancer audits utilise the nationally mandated flows of data from hospitals to the National Disease Registration Service (NDRS) in NHSE and the Wales Cancer Network in Public Health Wales. Each NATCAN audit has published key data items (Cancer Outcomes Services Dataset – COSD) for each cancer site, which hospitals can check are being completed and submitted to NDRS. More information regarding COSD and the COSD submission schedule can be found here: Cancer Outcomes and Services Data set (COSD) – NDRS (digital.nhs.uk).

Using this approach, NATCAN receives clinical information for every patient diagnosed with bowel, breast, lung, oesophago-gastric, ovarian, pancreatic, prostate, non-Hodgkin lymphoma and kidney cancer in England and Wales. Data from Trust/Health Board data submissions are linked to selected items from national datasets to provide information on the diagnosis, management and treatment of all patients newly diagnosed with each cancer type. That includes staging, mode of admission, comorbidities, surgical procedure or intervention.

Therefore, there is no need for NHS organisations to formally register for this audit, or input data on patients through a separate database portal. Additionally there is no audit specific deadline for trusts to submit data.

All audits within NATCAN only use linked national routinely collected datasets for its core outputs. This will make the process of producing relevant and robust performance indicators more efficient.

Rapid cancer registration data, that allows timely (three months following diagnosis) Quarterly reporting to providers, is used alongside more delayed State of the Nation reports based on “gold-standard” cancer registration datasets (data available at least 18 months after diagnosis). Concise State of the Nation reports will be produced annually.

Each audit in NATCAN will carry out a quality improvement initiative using the rapid cancer registration data at least once in the first three years. The aim is to “close the audit cycle”, following an approach commonly referred to as the “plan-do-study-act” method. This will be a first at national level for cancer audits.

All NHS Trusts in England and Health Boards in Wales that provide cancer services.

Yes, all NHS healthcare providers of cancer care are expected to participate in relevant HQIP-funded projects within the National Clinical Audit and Patient Outcomes Programme.

Details of the statutory and mandatory requirements for clinical audit are available on the HQIP website. 

Your local Data Improvement Lead, NDRS, will be able to help you find out information about your Cancer Outcomes Services Dataset (COSD) submissions. The key COSD data requirements for each audit are available here.

Please see below the list of regional contacts.

National
Karen Graham
[email protected]

East Midlands
Simon Cairnes
[email protected]

Eastern
Marianne Mollett
[email protected]

London
Katrina Sung
[email protected]

North West
Paul Stacey
[email protected]

Northern and Yorkshire
Rachel Mann
[email protected]

Oxford
Gemma Feeney
[email protected]

South West
James Withers
[email protected]

West Midlands
Gemma Feeney
[email protected]

All patient identifiable information including name, address, date of birth, address, postcode and NHS number is removed (de-identified) by NHSE in England and WCN in Wales before they are securely transferred to the NATCAN team.

In line with the National data opt-out policy, opt-outs are not applied to the data provided to NATCAN because the data are not Confidential Patient Information as defined in sections 251(10) and (11) of the National Health Service Act 2006.

Where individuals have opted out of disease registration by the National Disease Registration Service (NDRS), their data has been permanently removed from the registry and is not provided. More information can be found here.

The first year was a period of development – building organisational structures, recruiting staff, mapping the cancer service configuration in England and Wales, creating common data access channels with our data providers, developing performance indicators, and designing quality improvement (QI) plans.

Each audit completed a scoping exercise during Summer 2023, in consultation with key stakeholders, to determine the QI priorities and goals.  Scoping documents outlining the key QI priorities for each audit were published in November 2023. The performance indicators underpinning these QI goals will be reported from 2024 in a State of the Nation report which will be published in September 2024 for the six new audits. The existing audits published their first State of the Nation reports in January 2024 (prostate, oesophageal and bowel cancer).

Each audit will also report key performance indicators on a quarterly basis and on an interactive, web-based dashboard updated quarterly.

The current NATCAN reporting schedule is available here.

Patients and patient charities are involved in all aspects of the delivery of the cancer audits. For each audit, there will be a Patient and Public Involvement Forum to provide insight from a patient perspective on strategic aims and specific audit priorities. This will include shaping the development of each audit’s QI initiatives by ensuring this work is relevant from a patient perspective.

A key activity of the PPI Forums will be to participate actively in the production of patient-focussed audit outputs (including patient and public information, patient summaries of reports, infographics, and design and function of the NATCAN website). This will help guide us on how best to make this information accessible.

The chair of each audit’s PPI Forum will be a member of that audit’s Clinical Reference/Advisory Group to further strengthen the patient voice in the audits.

A priority for each audit in NATCAN is the development of a quality improvement strategy that includes explicit quality improvement (QI) goals aiming to improve cancer care and outcomes. Working closely with key stakeholders,  including people with lived experience of cancer, each audit designed the scope of the audits and identified key QI goals that will lead to significant patient benefits.

Quality improvement plans for each audit were published in September 2024. These plans define ten performance indicators, and how they map to the key QI goals, national guidelines, and standards. The performance indicators will be used by the audits to monitor progress towards its improvement goals and to provide a better understanding of the determinants of variation in the treatment of people with cancer and the outcomes they experience. In addition, the QI plans set out the improvement methods and activities that will support implementation of the plans, including strategies for reporting and disseminating results, in addition to describing the approaches to evaluation.

NATCAN will ensure that its quality improvement programme will be closely aligned with related activities implemented by other relevant organisations (for example CQC and Getting it Right First Time in England, and NHS Quality Improvement and Patient Safety in Wales).

Each audit within NATCAN will design and implement a national QI initiative in 2025. Again, NATCAN will build on the CEU’s longstanding experience in targeting and designing QI implementation approaches. This will ensure that the audit feedback information and recommendations truly reach the clinicians who can act on it, and will also incorporate specific action plans.

NAoPri and NAoMe are included in the Quality Accounts list from 2023/24.

NKCA, NPaCA, NOCA and NNHLA will be included from 2024/25.

For the first State of the Nation (SotN) reports in 2024, the new audits will not implement HQIP’s formal “outlier process” (i.e., a formal process to assess the performance of healthcare providers with results that are outside the expected range). This is because, although there is sufficient confidence to report the results publicly, it is the first time that provider-specific results are being provided with untested data completeness and quality, and risk adjustment methods are in development. Instead, where results highlight a potential cause for clinical concern, the audit team will contact the providers within one month following publication of the SotN Report, and work with them to explore factors that may explain their results, according to HQIP’s formal guidance. This process is with a view to being able to adopt the formal outlier process in 2025.

The National Cancer Audit Collaborating Centre (NATCAN) is a new national centre of excellence which will shine a spotlight on the care and treatment of patients who are diagnosed with cancer in England and Wales. It will bring all cancer audits together under one umbrella for the first time. The aim is to strengthen NHS cancer services by examining data on treatment and patient outcomes, in order to improve quality and results. It has been commissioned to produce new cancer audits by the Healthcare Quality Improvement Partnership (HQIP), on behalf of NHS England and the Welsh Government.

NATCAN is part of the Clinical Effectiveness Unit (CEU) in London – a collaboration between the Royal College of Surgeons of England (RCSEng) and the London School of Hygiene & Tropical Medicine (LSHTM). The CEU brings together the best clinicians (the doctors on the front line against cancer who know what the problems are) and the best academics (the data scientists and statisticians who can interpret the results generated by the data in the most effective way). It has already been working on cancer audits for more than 15 years.

NATCAN includes six new national cancer audits in breast cancer (primary and metastatic), ovarian, pancreatic, non-Hodgkin lymphoma and kidney cancer. These audits will cover roughly 90,000 newly diagnosed patients each year. The CEU has already delivered clinical audits in prostate, lung, bowel, oesophageal and stomach cancer, and it recently completed an audit of breast cancer in older patients. Over the next few years all these audits will become part of NATCAN. The aim is to deliver closer collaboration and better results, sharing learning and best practice.

NATCAN, comprising six new audits, is funded by NHS England and the Welsh Government, with £5.4m for an initial period of three years.

NATCAN is all about effective collaboration. Bringing senior doctors and academics together will ensure that we ask the right questions about cancer care and treatment, and then use the right methods to answer those questions. We’ll also work closely with different stakeholders including patient groups, to try to ensure that more people recover from cancer and lead longer healthier lives.

Clinical audit is a method that healthcare professionals use to look at and improve patient care. They compare how patients are treated, and the outcomes of the care they receive, against set standards and guidelines.

The audits in NATCAN use information on the care received by patients diagnosed with cancer in hospitals across England and Wales. They examine this data in order to make  valid comparisons, and identify improvements where they are needed. The audits which have already been delivered have helped provide a wider understanding of cancer treatments, and created better results for patients. They have also promoted improvement initiatives within NHS cancer services, and identified areas of best practice.

It’s important to remember that not all cancers are the same. So, we need to focus on each type of cancer individually. For example, over 70% of patients diagnosed with primary breast cancer will still be alive after ten years, but only 5% of patients diagnosed with pancreatic cancer will survive for ten years. We need to try to improve that.

We use information about patients that is collected by national organisations in England and Wales. These organisations include the National Cancer Registration and Analysis Service (NCRAS) in England and the Wales Cancer Network. They are allowed to collect data on patients diagnosed with cancer, the treatments they receive, and the results of these treatments.

No. All the data we use is anonymised, and doesn’t include the names of any individual patients or information such as an NHS number.

Yes. We now have access to more rapid cancer data, which is available three months after diagnosis. More traditional cancer data is only available eighteen months after diagnosis. This is a key innovation, which means NATCAN can feed results back to hospitals more frequently, to enable them to improve their cancer services. We can also measure whether these improvements are having the desired results.

The emergence of rapid data was driven by the Covid pandemic, and we are already using it to good effect in existing audits, to improve the diagnosis and treatment of patients.

In general terms, what we call the gold standard data is a much richer dataset which gives more detailed information about cancer. It might for example provide data on what particular cancer cells look like under a microscope, which may tell us whether they are likely to be more aggressive.

The rapid data has information about the patient, their diagnosis and their treatments. It has more limited information about the tumour – it only gives us information on staging, which is how medical experts determine the extent to which a cancer has grown and spread. So it can be really useful because it is available so quickly, but we still need the gold standard data to give us a more sophisticated analysis.

Our audits don’t just examine data about the cancers themselves, they also look at different hospitals and different methods of treatment. That means NATCAN will  focus on how cancer care varies from one hospital to another, with the aim of learning lessons and identifying how we can fight different cancers most effectively.

We will make recommendations to hospitals based on our findings, which will include:

• How patients are diagnosed
• The treatments patients receive such as the use of surgery, radiotherapy and/or chemotherapy
• Outcomes following treatment

To make fair comparisons, we also take account of the facts that all patients are different and have different characteristics. Among the factors we consider are age, whether a patient has pre-existing conditions, and the social or economic circumstances that patients find themselves in. When the data tells us where improvements are needed, NATCAN will lead the drive to deliver change.

Yes, patient involvement is central to everything we do. We are determined to give patients and carers a greater voice at every stage of the process. NATCAN will work with various patient charities, to create a patient forum for each cancer audit. These patients will help ensure that the questions we ask in the audits are appropriate, and that we are reporting information in ways that are useful to the public as well as to health care professionals and hospitals.

We now have our teams in place, and the next steps are to work with professionals and patients to make sure we ask the right questions and the quality improvement goals for each of the new audits are clear. Once the audit questions have been finalised, and the data has been gathered and analysed, we hope to be publishing results beginning in early 2024. We will also prepare short state-of-the-nation reports for each cancer audit, which will each include five specific recommendations. We aim to publish these reports by September 2024.

The National Bowel Cancer Audit (NBOCA) was established to describe and compare the diagnosis, care and outcomes of patients diagnosed with bowel cancer in England and Wales; it is now well established and each annual State of the Nation Report includes data on over 30,000 patients. The Audit’s overall aim is to measure the quality of care and survival of patients with bowel cancer in England and Wales.

The audit is commissioned by the Healthcare Quality Improvement Partnership (HQIP) and has been developed by the Association of Coloproctology of Great Britain and Ireland (ACPGBI). It is managed by the National Cancer Audit Collaborating Centre (NATCAN) on behalf of the Clinical Effectiveness Unit (CEU) of the Royal College of Surgeons of England.

No. If you are representing a devolved nation and wish to submit data to NBOCA please contact HQIP who will be able to advise.

The Audit receives an upload of colorectal cancers diagnosed and managed in Wales centrally from the Cancer Network Information System Cymru (CaNISC) system.

NBOCA has moved into the National Cancer Audit Collaborating Centre (NATCAN) at the Clinical Effectiveness Unit of the Royal College of Surgeons of England (RCSEng).

NBOCA retains the same core team and now resides within NATCAN. NATCAN includes four established cancer audits and six newly commissioned cancer audits.

NBOCA continues to focus on robust reporting of data for all people with bowel cancer, earlier availability in reporting outcomes, and a major ongoing emphasis on implementation of quality improvement initiatives.

The National Cancer Audit Collaborating Centre (NATCAN) is a national centre of excellence which shines a spotlight on the care and treatment of people who are diagnosed with cancer in England and Wales. The Healthcare Quality Improvement Partnership (HQIP), on behalf of NHS England and the Welsh Government, has commissioned the development and establishment of NATCAN, which is part of the National Clinical Audit and Patient Outcomes Programme (NCAPOP). It aims to:
• Provide regular and timely evidence to cancer services of where patterns of care in England and Wales vary
• Support NHS services to identify the reasons for the variation in care in order to guide quality improvement initiatives
• Stimulate improvements in cancer detection, treatment and outcomes including survival

Work on setting up the new centre began on October 1 2022. NATCAN is funded by NHS England and the Welsh Government.

• All audits within NATCAN will only use linked national routinely collected datasets for its core outputs. This will make the process of producing relevant and robust performance indicators more efficient.
• Rapid cancer registration data, that allow timely (three months following diagnosis) Quarterly reporting to providers, will be used alongside annual State of the Nation reports based on “gold-standard” cancer registration datasets (data available at least 18 months after diagnosis).
• Each audit in NATCAN will carry out a quality improvement initiative using the rapid cancer registration data at least once in the first three years. The aim is to “close the audit cycle”, following an approach commonly referred to as the “plan-do-study-act” method. This will be a first at national level for cancer audits.

In order to reduce burden on hospital staff, the audits in NATCAN, similar to the existing audits in prostate and lung cancer, no longer ‘collect’ clinical data. The cancer audits utilise the nationally mandated flows of data from hospitals to the National Disease Registration Service (NDRS) in NHSE and the Wales Cancer Network in Public Health Wales. Each NATCAN publishes a minimum dataset [NBOCA Key COSD Data Items 2025], comprising relevant data items for each cancer site, which hospitals can check are being completed and submitted to NDRS or the Wales Cancer Network.

NBOCA still encourages clinicians to engage with coders and data administrators to ensure data accuracy, especially on staging information provided to NDRS and the Welsh Cancer Network.

Using this approach, NBOCA will receive clinical information for every person diagnosed with bowel cancer in England and Wales. Data from Trust/MDT data submissions are linked to selected items from national datasets to provide information on the diagnosis, management and treatment of all patients newly diagnosed with each cancer type. That includes patient and tumour characteristics, diagnostic tests and imaging, hospitals appointments and admissions, procedures, treatments, interventions and outcomes.

For 2024 reporting onwards (people diagnosed since April 2022), NBOCA will use cancer registry data which includes multiple data sources submitted by trusts, one of the main ones being the Cancer Outcomes and Services Dataset (COSD). The vast majority of NBOCA data items are COSD items – please refer to NBOCA Key COSD Data Items 2025. We therefore ask hospitals to check the data quality of these data items entered into COSD or the Wales Cancer Network, particularly staging data. CancerStats2 provides trust-level data completeness of key COSD items for hospitals in England.
NBOCA will also be using the rapid cancer registry dataset, much of which comes from COSD. It is important that hospitals regularly upload accurate COSD data to NDRS.
Trusts are encouraged to submit all data available on a monthly basis in-line with the COSD reporting timescales. It is expected that the majority of diagnosis and treatment data are submitted within six months of diagnosis. Once the full patient pathway is linked together, the data are provided to the NBOCA team to analyse. Further information about the COSD and reporting timescales can be found at the following link:
https://digital.nhs.uk/ndrs/data/data-sets/cosd#submission-schedule
For queries regarding data submissions in England, the Data Liaison team within the NDRS has a wealth of knowledge on cancer pathways and processes within NHS Trusts. Contact details for the regional Data Liaison Managers can be found at the following link:
NDRS – Regional Data Liaison Managers

• Right hemicolectomy
• Extended right hemicolectomy
• Transverse colectomy
• Left hemicolectomy
• Sigmoid colectomy
• Anterior resection
• APER
• Pelvic exenteration
• Hartmann’s procedure
• Total colectomy and ileorectal anastomosis
• Total excision of colon and rectum
• Total excision of colon and rectum + anastomosis of ileum to anus + create pouch

The audit uses the pre-2004 National Confidential Enquiry into Patient Outcomes and Death (NCEPOD) classification of surgical urgency, despite there being an update to this.

The arguments to maintain the pre-2004 NCEPOD definition are that the classification based on this definition correlates strongly with:

• known risk factors for emergency treatment (age, socio-economic deprivation, and presence
  of co-morbidity)
  • the mode of admission coded in HES
  • the observed 90-day mortality.

Introducing a new classification system for a key characteristic of the surgical procedure would make it impossible to compare outcomes in different audit periods which would in turn make it impossible to monitor trends in outcome over time, which is one of the key functions of the audit.

Yes. From about 30,000 cases, using ‘rectosigmoid’ as the site of cancer generated a subset of 400 cases which could not be usefully analysed. Therefore we would encourage hospitals/trusts/MDTs to ensure that they are assigning either ‘sigmoid’ or ‘rectum’ accordingly to cases.

The patient cohort included in the 2020 annual report pre-dates the pandemic and so the results within the 2020 annual report are unaffected. However, due to pressures on providers during the initial phase of the pandemic we were unable to do our usual data checking process, and this is why there is more incomplete data for this reporting period than we would usually expect.

The 2021 report includes patients diagnosed primarily between 01 April 2019 and 31 March 2020. Major resections up to 31 March 2020 are included in order to avoid the impact of the pandemic. Patients diagnosed before 31 March 2020 and undergoing major resection after this date are included in the 2022 report. The pandemic will have started to have an impact during the period in the 2021 report.

The 2022 report includes patients diagnosed between 01 April 2020 and 31 March 2021, and patients diagnosed between 01 April 2019 and 31 March 2020 who underwent a major resection after 31 March 2020. All of these patients were diagnosed and/or treated during the COVID-19 pandemic and their outcomes are not outlier-reported. The only outcome that is outlier-reported in the 2022 report is 2-year all-cause mortality after major resection because it includes patients having surgery before the pandemic.

The ACPGBI/NBOCA recommend that ASA grade of each patient must be determined by the anaesthetist alone before resection of the cancer. The anaesthetist commonly gives this judgement as part of the “Time Out” – before the surgical procedure starts. The Colorectal Surgeon should record the ASA grade given by the anaesthetist in the operation note and this will be the grade submitted to NBOCA.

ASA grade is a central component of NBOCA risk-adjustment. Feedback from some MDTs has indicated that the diagnosis of colorectal cancer alone has been used routinely to justify ASA II – despite the fact that the large majority of colorectal cancer patients have localised disease at the time of resection and not systemic disease.

Definition of the data completeness measure used by NBOCA in its reporting and in Trust Results

Data completeness is defined as the proportion of patients with complete data for the variables age, sex, ASA grade, pathological TNM stage (tumour, node, metastasis staging) and site of cancer. This is because these seven variables are used for risk-adjustment. Mode of admission and number of co-morbidities are also used in the risk-adjustment model but are collected from HES/PEDW data and so are not included in the assessment of data completeness. Data completeness is only assessed in patients who underwent major resection because only in these patients could all seven data items be expected to be complete.

The audit includes all patients with a primary diagnoses of bowel cancer within the current report period. Included patients must be:

1) Aged 18 or older at the date of diagnosis
2) Diagnosed in the audit period (April-March)
3) Diagnosed with colorectal cancer for the first time, with one of the following ICD10 codes:

• C18 Malignant neoplasm of colon
• C20 Malignant neoplasm of rectum
• C19 Malignant neoplasm of rectosigmoid junction

Non Primary Cancers (recurrences and progressions) should also be submitted to NDRS in England.

The following patients are excluded from the audit:
• Sarcomas
• Lymphoma
• Neuroendocrine/Carcinoid tumours
• Melanoma

No. From 1 April 2022 the audit no longer collects patients with a primary diagnoses of anal cancer (ICD10 code C21).

If a patient is deemed palliative, and they are unfit for a biopsy, and the MDT consensus is that this a colorectal malignancy, the patient should be included in NBOCA.

• H04 Total excision of colon and rectum
• H05 Total excision of colon
• H06 Extended excision of right hemicolon
• H07 Other excision of right hemicolon
• H09 Excision of left hemicolon
• H10 Excision of sigmoid colon
• H11 Other excision of colon
• H29 Subtotal excision of colon
• H33 Excision of rectum
• X14 Clearance of pelvis
• H40.4 Trans-sphincteric anastomosis of colon to anus
• H41.1 Rectosigmoidectomy and peranal anastomosis
• H41.4 Peranal mucosal proctectomy and endoanal anastomosis
• H47.9 Unspecified excision of anus

Data on colorectal cancer outcomes during COVID-19 and the recovery phase will not be used for benchmarking of providers.

The patient cohort included in the 2020 annual report pre-dates the pandemic and so the results within the 2020 annual report were unaffected. However, due to pressures on providers during the initial phase of the pandemic we were unable to do our usual data checking process, and this is why there is more incomplete data for this reporting period than we would usually expect.

The 2021 report included patients diagnosed primarily between 01 April 2019 and 31 March 2020. Major resections up to 31 March 2020 were included in order to avoid the impact of the pandemic. Patients diagnosed before 31 March 2020 and undergoing major resection after this date were included in the 2022 report. The pandemic had started to have an impact during the period in the 2021 report.

The 2022 report included patients diagnosed between 01 April 2020 and 31 March 2021, and patients diagnosed between 01 April 2019 and 31 March 2020 who underwent a major resection after 31 March 2020. All of these patients were diagnosed and/or treated during the COVID-19 pandemic and their outcomes are not outlier-reported. The only outcome that is outlier-reported in the 2022 report is 2-year all-cause mortality after major resection because it includes patients having surgery before the pandemic.

The 2023 State of the Nation report includes patients diagnosed between 01 April 2021 and 31 March 2022. These patients were diagnosed during the COVID-19 pandemic and their outcomes are not outlier-reported. The only outcome that is outlier-reported in the 2023 report is 2-year all-cause mortality after major resection because it includes patients having surgery before the pandemic.

Following publication of the report, queries about data reported in the annual report will be answered until the end of June 2024. NBOCA is not able to provide individual hospitals with details of the patients included in their results following publication of the report.

Please note that NBOCA no longer collects its own data. The Clinical Audit Platform system has now been closed and for patients diagnosed from 1 April 2022, NBOCA uses existing data sources.

Data completeness is defined as the proportion of patients with complete data for the variables age, sex, ASA grade, pathological TNM stage (tumour, node, metastasis staging) and site of cancer. This is because these seven variables are used for risk-adjustment. Mode of admission and number of co-morbidities are also used in the risk-adjustment model but are collected from HES/PEDW data and so are not included in the assessment of data completeness. Data completeness is only assessed in patients who underwent major resection because only in these patients could all seven data items be expected to be complete.

Length of hospital stay was defined as the number of days between date of surgical procedure as recorded in HES/PEDW, and either discharge or death. The audit uses length of stay >5 days as an outcome because it is in keeping with the median length of stay reported in randomised trials of enhanced recovery programmes and large cohort studies. It reflects good quality post operative care and complication free recovery.

J Clin Oncol. 2014 Jun 10;32(17):1804-11. doi: 10.1200/JCO.2013.54.3694. Epub 2014 May 5
Ann Surg. 2015 Jun;261(6):1153-9. doi: 10.1097/SLA.0000000000001029.

90-day mortality is defined as death from any cause, according to ONS, within 90 days of major resection. Date of major resection is according to NBOCA.

NBOCA reports 90-day rather than 30-day mortality. From a patient’s perspective the risk of post-operative death at 3 months is just as significant an outcome as death within 1 month of surgery. Post-operative death at 3 months captures those deaths that occur after prolonged critical care support which is now a much more common feature of colorectal cancer resection and adds significantly to the procedure-associated death rate. A previous study showed that the vast majority of deaths occurring within 90 days of surgery were as a result of complications of the surgery [Archives of Surgery 2009; 144: 1021-1027].

30-day unplanned readmission is defined as an emergency admission to any hospital for any cause within 30 days of surgery, according to HES. Date of surgery is taken from HES. Emergency admission is defined in HES as admission via Accident and Emergency services, or emergency admission via general practitioner, Bed Bureau, or consultant outpatient clinic.

30-day unplanned return to theatre is defined as the presence of any of a set of OPCS codes for reoperation in HES/PEDW within 30 days of surgery. The majority of OPCS codes are only valid on days 1-30 after surgery to avoid classifying procedures which were part of the original major surgery as an unplanned reoperation.

Rectal cancer patients undergoing an anterior resection, according to NBOCA, and who receive an ileostomy within 30 days of their procedure, according to HES/PEDW, are included in the denominator. Patients without a procedure code for stoma reversal (OPCS code G753 or H154) within 18-months of surgery, according to HES/PEDW, are assumed to have an unclosed ileostomy at 18 months (the numerator).

A patient with an ileostomy who dies within 18 months before having it reversed is included in the numerator and the denominator of the 18-month unclosed ileostomy rate. Dying before a stoma is reversed is a poor outcome which, it was felt, should not be excluded from the estimate. The proportion of rectal cancer patients with a “temporary” stoma who die within 18 months of surgery before having their stoma reversed is relatively small and therefore the inclusion of these patients has only a small effect on the 18-month unclosed ileostomy rate.

The observed 2-year mortality rate is the number of patients who died within 2 years divided by the sum of the amount of time each patient is followed for. For example, for patients who survived for the 2 years their follow-up time is 2 years but for a patient who died at 3 months their follow-up time is 3 months.

2-year mortality rate is not the number of patients who died within 2 years divided by the number of patients included in the estimate; it also takes into account when each patient died. Taking into account the amount of follow-up time means that the estimate compares not just the proportion of patients who died within 2 years but also how quickly they died.

Consider as an example two units in which the same proportion of patients die within 2 years. In this example the unit in which patients die earlier will have a higher 2-year mortality rate. This standard method for estimating longer-term mortality rates is called ‘Survival Analysis’.

Data on colorectal cancer outcomes during COVID-19 and the recovery phase have not been used for benchmarking of providers.

The patient cohort included in the 2020 annual report pre-dated the pandemic and so the results within the 2020 annual report were unaffected. However, due to pressures on providers during the initial phase of the pandemic we were unable to do our usual data checking process, and this is why there is more incomplete data for this reporting period than we would usually expect.

The 2021 report included patients diagnosed primarily between 01 April 2019 and 31 March 2020. Only major resections up to 31 March 2020 were included in order to avoid the impact of the pandemic. Patients diagnosed before 31 March 2020 and undergoing major resection after this date were included in the 2022 report.

The 2022 report included patients diagnosed between 01 April 2020 and 31 March 2021, and patients diagnosed between 01 April 2019 and 31 March 2020 who underwent a major resection after 31 March 2020. All of these patients were diagnosed and/or treated during the COVID-19 pandemic and their outcomes were not outlier-reported. The only outcome that was outlier-reported in the 2022 report was 2-year all-cause mortality after major resection because it included patients having surgery before the pandemic.

The 2023 report included patients diagnosed between 01 April 2021 and 31 March 2022. All of these patients were diagnosed and/or treated during the COVID-19 pandemic and their outcomes were not outlier-reported. The only outcome that was outlier-reported in the 2023 report was 2-year all-cause mortality after major resection because it included patients having surgery before the pandemic.

Age (modelled as age plus age-squared), sex, performance status, T-stage, N-stage, M-stage, cancer site, mode of admission (from HES/PEDW), number of co-morbidities (Charlson Score from HES/PEDW), and the interaction between age and distant metastases are included in the risk adjustment model. The strongest of the risk-factors that come from NBOCA are age, performance status and TNM stage, and it is particularly important that these are complete.

The risk-adjustment model for two-year mortality additionally includes interactions between follow-up period (0-3 months after surgery vs. 3-24 months after surgery) and all of the risk factors. This allows risk factors to have a different effect shortly after surgery and in the longer term. For example, the effect of performance status is much larger peri-operatively than in the longer-term, whilst cancer stage has a much larger impact on longer-term than short-term mortality.

The risk-adjustment for 18-month unclosed ileostomy is the same as for 90-day mortality but excludes ‘cancer site’ because it includes only rectal cancer patients.

If your trust/network has unusually low-risk patients compared to all patients nationally, for example they tend to be younger, or have lower performance status, or less advanced cancer, the adjusted outcomes for your trust/network will be higher than the observed outcomes. Conversely, if your trust/network has unusually high-risk patients compared to all patients nationally, the adjusted outcomes for your trust/network will be lower than the observed outcomes.

Histological TNM staging is used where it is available; otherwise radiological TNM staging is used. NBOCA no longer collects information about Dukes Staging, therefore is no longer able to update missing M-Stage data. Trusts should ensure M stage is completed, and update from their own record of Dukes’ stage where necessary.

The aim is to adjust for patient factors which reflect frailty of the patient and which cannot be influenced by the provider, so that apart from random variation, any remaining differences in outcomes between providers should reflect differences in quality of care. Providers have influence, to some extent, over the type of surgical procedure, the surgical urgency, and whether laparoscopic techniques are used, and these factors should not, therefore, be adjusted for.

The audit uses the pre-2004 National Confidential Enquiry into Patient Outcomes and Death (NCEPOD) classification of surgical urgency, despite there being an update to this.

The arguments to maintain the pre-2004 NCEPOD definition are that the classification based on this definition correlates strongly with:

• known risk factors for emergency treatment (age, socio-economic deprivation, and presence
  of co-morbidity)
  • the mode of admission coded in HES
  • the observed 90-day mortality.

Introducing a new classification system for a key characteristic of the surgical procedure would make it impossible to compare outcomes in different audit periods which would in turn make it impossible to monitor trends in outcome over time, which is one of the key functions of the audit.

Patients with missing date of surgery are excluded, and multiple imputation, with 10 imputed datasets, is used to fill in any missing information on the risk factors. The method, known as Multiple Imputation using Chained Equations, uses a patient’s other risk-factors to predict their missing information, whilst taking into account the uncertainty due to their missing information. In addition to the data items in the risk-adjustment model, and the outcomes, the following items are used to predict missing risk-factors: surgical urgency, mode of admission according to NBOCA, surgical procedure, number of lymph nodes extracted, number of positive lymph nodes extracted, Index of Multiple Deprivation, length of hospital stay, and days from diagnosis to surgery.

The number of co-morbid conditions a patients has is measured using the Charlson Co-morbidity Score, which is calculated using HES/PEDW. A co-morbidity is defined as any hospital admission with one of the following diagnoses in the last year, including the current admission:

• congestive cardiac failure
  • peripheral vascular disease
  • cerebrovascular disease
  • dementia
  • rheumatological disease
  • liver disease, diabetes
  • hemiplegia/paraplegia
  • AIDS/HIV;

or any of the following diagnoses at a previous hospital admission in the last year:

• myocardial infarction
  • chronic pulmonary disease
  • chronic renal disease.

The patient does not need to be admitted with the co-morbidity for it to be included. The co-morbidity needs to be included in the patient notes and from there, to make its way into HES, to be included. This can be recorded in the notes at the admission for the bowel cancer resection.

See British Journal of Surgery 2010; 97: 772–781 for more details.