Diagnostic Imaging Data Set (DIDS) data product

The DIDS data product is created from monthly submissions of data on diagnostic imaging tests carried out on NHS patients, extracted from local RIS.

Data submitted to the DIDS collection covers 4 areas, providing information about the:

• patient (such as NHS number, date of birth, gender, ethnicity)
• referrer (referrer code, referring organisation code)
• imaging provider (organisation site code)
• imaging examination (imaging codes, key dates in the imaging process)

The DIDS data product is produced by applying additional derivations, cleaning, and data transformations to the collection, this improves the analytic utility and opportunity for the product to benefit multiple user groups.

The DIDS data product includes information about examinations conducted on NHS patients in England including NHS trusts, NHS foundation trusts and independent sector providers who provide NHS funded diagnostic imaging tests.

The data is extracted from providers RIS and submitted monthly. The DIDS collection includes activity undertaken since April 2012.

Each DIDS record contains a wide range of information about the diagnostic imaging test, including information on the:

• patient (such as NHS number, date of birth, gender, ethnicity)
• referrer (referrer code, referring organisation code)
• imaging provider (organisation site code)
• imaging examination (imaging codes, key dates in the imaging process) 

Further information is derived from the submitted data, including: 

• geographic information (Lower and Middle Super Output Area)
• commissioning groups
• organisation names (for example trust sites, GP practices) 
• imaging related information (such as modality, body region, body system)
• days between key imaging dates (for example days from test request to test, days from test to service report issue) 

Data not captured on the provider’s RIS such as for breast screening or cardiac ultrasound activity is not included in the collection. The images that are produced from the tests or post mortem imaging are not included.

The DIDS can be used to:

• provide accurate details on the specific imaging tests performed and the demographics of the patients at a national and sub-national level
• enable analysis of demographic and geographic variation in access to different test types and different providers
• assess effective delivery of care
• provide information on the utilisation of high value imaging equipment
• monitor trends in care and towards improving outcomes
• provide information to improve diagnostic services
• link to other datasets, most notably cancer registration data

The Data Set Development Service (DSDS) hosted consultation webinars with DIDS providers/submitters and system suppliers to explain and discuss the requirements that have been gathered for version 2.0 of the DIDS. The slide decks from each webinar are provided below.  

Aggregated DIDS data at trust level is available from the NHS England Performance Analysis Team.

The detailed data, including that which is linked through the Hospital episode statistics, is only available through the Data Access Request Service, and users have to prove a valid legal case for needing access to the information.

The following links give details of submitted data quality in DIDS:

• Data Quality Coverage Completeness and Data Quality Summary (CCDQS) report
• Data Quality Maturity Index (DQMI)

Providing data products that facilitate effective linkage with other data sources is a key component in enabling the effective utilisation of our data products to meet a wide range of our analytical user needs. 

The way in which we facilitated linkage of DIDS data to occur changed in 2021. This was through the introduction of the Master Person Service (MPS) Person ID which will enable direct linkage of patient records across data sets such as HES and the MSDS, reducing the time and complexity in the analysis of DIDS data.

Prior to this point linkage methods of DIDS data utilised a methodology reliant on an initial linkage with the Hospital Episode Statistics, through the HES-DIDS linkage. Historical information and publications related to this linkage approach.