Cancer Outcomes and Services Data set (COSD)

The Cancer Outcomes and Services Data set (COSD) is a compiled data set which provides the standard for secondary uses information required to support national cancer registration and associated analysis (at local, regional, national, and international level), as well as other national cancer audit programmes.

This standard consists of:

• a set of individual data items, with their definitions
• the assemblage of these data items into discrete data sets
• the means of flowing the data items
• compilation of the data items into a single reconciled and verified data set

All patients diagnosed with or receiving cancer treatment in or funded by the NHS in England are covered by the standard. This includes adult and paediatric cancer patients.

Providers of cancer services have been required to provide a monthly return on all cancer patients diagnosed from 1 January 2013 using this data set. Data are collated via the National Disease Registration Service (NDRS) local offices, and formal mechanisms for transmission of data from Providers to NDRS have been extended to carry COSD.

Why is COSD needed?

Periodically we need to revise the COSD to ensure that we meet the current information requirements for the NHS.

The ‘NHS Long Term Plan’ aims to save thousands of lives each year by dramatically improving how we diagnose and treat cancer. The ambition is that by 2028, an extra 55,000 people each year will survive for five years or more following their cancer diagnosis.

The need to have strong cancer data collection, empowers NHS England to enforce this through the mandate of data collections. These data will be the base for cancer analysis and research for the next 5 years.

What is included in the COSD data collection?

The COSD specifies the data items that need to be recorded for all cancer patients by the NHS in England. This includes all the items that Providers should submit electronically directly to the NDRS on a monthly basis.

These items can be submitted from different systems such as Cancer Management Information System software, PAS (Patient Administration Systems) and Pathology Laboratory Information Management Systems (LIMS).

Whilst some of these items are generic there are also a number of site-specific items which are required in order to record and analyse services and outcomes. These items are also required locally by service providers for patient management and clinical care.

This guide provides a description of the data items, the tumour sites or disease types to which they apply, and any further information needed to collect them.

Some items in the COSD are submitted through other standard NHS routes such as Cancer Waiting Times and do not need to be submitted directly for COSD (although some key items, such as treatment details, need to be submitted for both).

Data from all sources, whether direct Provider submissions from other national collections or derived from other sources, are linked by the NDRS at patient and tumour level using NHS Number to complete the full data set.

More information can be found in the Change Specification, Requirements Specification and Implementation Guidance on the NHS Digital website or supporting documentation can be found in the downloads and additional resources sections of this page.

The National Disease Registration Service (NDRS) held a series of roadshows between January and February 2024. These explained the changes to the Cancer Outcomes and Services Data Set (COSD) and other key data set changes which effect the collection, quality assurance and reporting of Cancer Data.

The roadshows were held around England at eight different locations and provided a networking opportunity for Cancer Services staff in NHS Trusts to meet other teams within their region.

You can find out more on the roadshow events page. 

What's new in COSD 2024

The new version of COSD v10.0 came into effect on the 1 April 2024. These changes continue to build on the work started in v7.0 and further rolled out through v8.1 and v9.0. They include some new amendments and re-alignments to the current data set, as well as a revision of the current schema specification in order to continue to meet the business objectives of the standard.

The COSD v10.0 amendments were made following extensive consultation over a 9 month period with 50 key groups, that included over 120 subject matter experts (SMEs) in all fields of cancer and data processing.

In addition, COSD has been through a rigorous clinical review/assessment, this has involved talking to:

• Royal Colleges
• specialist tumour site specific groups
• leading consultants, across all disease types:
• cross referencing other data sources to reduce burden
• National Disease Registration Service (NDRS)
• NHS England (NHSE), including the former NHS Digital
• NHS Wales
• national cancer audit collaborating centre (NATCAN)
• all proposed changes were reviewed by the COSD Advisory Board
• all recommendations were approved by the overarching COSD Governance Board

This revision allowed the data sets to be clinically reviewed, validated and updated by experts in all fields of cancer, and provides a clinically sound set of data to be collected from April 2024 onwards.

Wherever possible, duplication across the data set has now been removed and full explanations of how to collect these data within the new structure are provided within the change logs of each data set and the user guides.

Maintaining key mandated data items was vital in this release, to continually improve data quality and reduce the burden of data processing within NCRAS. If a treatment record for example is submitted without a date or modality, it is of no use as a cancer registration event, however a registration officer would still have to review each incomplete record submitted, this multiplied by thousands of incomplete records per year was an unsustainable practice.

It also provides a clinically sound set of data which meets crucial recommendations in the ‘NHS Long Term Plan’, which aims to save thousands of lives each year by dramatically improving how we diagnose and treat cancer. The ambition is that by 2028, an extra 55,000 people each year will survive for five years or more following their cancer diagnosis.

Key changes to COSD

In total, 64 new data items (42 pathology specific) were added to meet the changing demands of cancer treatment and outcome data. In addition, there were 104 data items deleted, of which 28 are pathology specific. More importantly, this version continues to have a strong emphasis on improving data quality and ascertainment.

Many sections in the core have mandatory elements within them, this will drive up data quality without creating undue burden on either the people collecting the data (within the Trusts) or those processing the data (within NCRAS).

Other new features in v10.0 include:

• certain key data items are mandatory, to improve data quality and reduce the burden of data processing
• the addition of choices to data items to enable clearer decision making and improve data quality
• an update of the pathology data items to align with the Royal College of Pathologists’ ‘Core’ data sets
• new data items to support the Living With and Beyond Cancer campaign
• an improved mechanism for recording all ‘Non Primary Cancer Pathway’ to improve collection and data quality
• realignment or movement of data items, to ensure that data nests correctly within the XML

Many data have been re-aligned across the data set into the correct higher level groupings. The data set maintains its ability to be interpreted within the following 2 subsets of data.

Pathology

Ongoing linkage with the Royal College of Pathologists (RC Path) ‘Core’ data sets is vital and continues to be a priority to ensure clinical accuracy. This data set was reviewed by the chair of the Royal College of Pathologists Working Group on Cancer Services.

Working closely with the college is vital to ensure that COSD maps exactly to their specified data items and names. This will ensure that there is no burden on the histopathologists in recording these data, as they are mandated to collect these via the RCPath. In addition, it also reduces the burden on reporting for system suppliers to an absolute minimum, as they can map directly from their main tables to the export reports required for COSD.

It uses a different schema from COSD and has been formally separated within this version review and release.

Patient pathway

The removal of the pathology data items into their own specific data set in v9, resulted in a reduction on burden of data collection for MDT Coordinators of up to 30%. In v10 there is a further 15% reduction, resulting in an overall burden reduction of up to 45% in 3 years.

This shows we are responding to concerns from Trusts about the size and complexity of COSD. It is important to remember though that there is still more work needed in v11 to maintain COSD as the leading data collection of cancer data in England.

Collaboration between the (CWT) data set developers and COSD have improved both data sets by removing or enhancing specific shared data items.

The downloads and additional resources section of this page contain updated versions of the COSD, Guidance and supporting documentation for both the main COSD and the final pathology specific data set. It also includes links to download the schema packs to support structured XML submissions.

See the NHS Digital website for all other documentation, including the new Specification and Implementation guide.

Following a late change to the COSD schema packs, which was required to fix some uncaptured errors during testing, full implementation for COSD was put back from the 01 July 2024, to the 01 September 2024. Therefore, all COSD files MUST be uploaded to the API portal using COSD v10 no later than the November upload, otherwise the Trust will become 'Non-Compliant'.

The schedule below gives the deadline for providers to submit the COSD data for each calendar month of diagnosis/treatment. There is a later deadline for PAS feeds.

Feedback reports for the data submitted are available through the CancerStats2 website - (this opens in a new page)

Please note that this platform requires an N3/HSCN secure network connection. 

We are here to help and value feedback and suggestions for how we can improve COSD. 

COSD helpdesk

If you have queries, requests for further information, comments and suggestions for newsletter content or possible new data to be considered for future COSD version changes please contact the COSD helpdesk at [email protected] 

The Data Liaison team within the National Disease Registration Service (NDRS) has a wealth of knowledge on cancer pathways and processes within NHS Trusts. NHS teams submitting data to NDRS can seek advice, support and find out more about the data improvement initiatives available to them directly from the regional Data Liaison Managers:

If you don't currently receive the newsletter and would like to be on the mailing list, please can you use this link to join the COSD newsletter mailing list, completing all the fields and ensure to select COSD Newsletter from the list. When the next newsletter is published you will then automatically be sent this.

Download issue 23 - Oct 2023

Download Issue 24 - Apr 2024

Download Issue 25 - Sept 2024

There are lots of resources available to support users with the implementation and collection of data as part of the COSD data set.

Here is a summary of the documents available:

Users can also refer to the NHS data model and dictionary developed for users involved in the collection of data and the management of information in the NHS.

To download either the main COSD or pathology schema packs, you first need to create a TRUD account.

How to create a TRUD account

Go straight to the NHS Digital TRUD website and:

• select 'create one now' (directly under 'log in')
• fill out the online form
• you will be sent a password
• log in with your new password - once logged in you can change your password via 'manage account' (top right hand of the screen)

How to download a schema pack

Once you have a TRUD account:

• go to the NHS Digital TRUD website and log in
• select 'DD XML Schemas' from the 'downloads' section (far left of the screen)
• identify the schema pack you want and 'subscribe to this data set'
• tick 'I accept the licence' and then 'request this subscription'
• you will receive a confirmation email
• download the required schema pack