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Diagnostic Imaging Dataset

A collection of data on diagnostic imaging tests, such as x-rays and MRI scans, taken from NHS providers' radiological information systems.

What is the Diagnostic Imaging Dataset (DID)?

The Diagnostic Imaging Dataset (DID) is a central collection of detailed information about diagnostic imaging tests carried out on NHS patients, extracted from local radiology information systems and submitted monthly.

The DID captures information about referral source and patient type, details of the test (type of test and body site), demographic information such as GP registered practice, patient postcode, ethnicity, gender and date of birth, plus items about waiting times for each diagnostic imaging event, from time of test request through to time of reporting.

All NHS providers are required to submit DID data to the HSCIC as mandated by the Burden Advice and Assessment Service (BAAS) and Monitor. The HSCIC collects the DID on behalf of NHS England who provide further information about the data set on the NHS England DID web page.

Those who submit DID data upload it securely to the DID system via a dedicated DID website. The site provides the submission timetable and further information and guidance on the data set.

The DID enables analysis of demographic and geographic variation in access to different test types and different providers. Further information on the benefits of DID are available via the DID website.


What data is available in DID?

The DID includes information on imaging tests carried out from 1 April 2012. It does not include the images that are produced as a result of these tests.

For a full description of each of the fields available in DID, please see the pdf icon DID Data Dictionary [232kb].

Is DID linked to other data sets?

The DID is now routinely linked to Hospital Episode Statistics (HES).

Hospital Episode Statistics (HES) contains around 1 billion records on patients attending Accident and Emergency units, being admitted for treatment or attending outpatient clinics at NHS hospitals in England.

The HES-DID linkage enables users to analyse acute secondary care pathways for patients receiving diagnostic imaging tests in England. This analysis could help to identify trends and variation in patient outcomes and be used to improve services for patients.

The linkage adheres to strict Information Governance procedures and customers have to make a formal application and sign a legally binding data sharing contract to access the data.

How can I access DID data?

NHS England

Aggregated data at Trust level is available via the NHS England DID webpage.


iView is a reporting system that is used across several HSCIC data sets.  It provides aggregate views of data based on a set of common attributes. As such, no patient identifiable data is displayed.

DID data is available via iView to employees of NHS and NHS-affiliated organisations. To request access to iView for DID, please email

The Data Linkage and Extract Service

The HSCIC's Data Linkage and Extract Service provides extracts from a range of individual and routinely linked data sets. It can also add significant value by combining and matching data sets at individual record level in a secure environment.

The data provided by the service is normally pseudonymised and identifiable data is only provided when there is a lawful basis to do so.

The DID and the HES-DID routine linkage can both be accessed via this service.

For further information about the service and the range of products and data sets available, please visit the Data Linkage and Extract Service page.

What analysis of DID is available?

DID data is reported on at summary level by NHS England who make reports available via the NHS England DID page.

A statistical publication of a sample of linked HES-DID data will be published by the HSCIC on 2 October 2013. This will include analysis to demonstrate how the linked data can be used.

What information is available on DID data quality?

A DID Data Quality Report is managed and produced by NHS England.

In addition a pdf icon static data quality notice [349kb] is available which gives an overview of the data quality issues which users of DID data should be aware of.

The Data Quality Maturity Index is a new quarterly publication intended to raise the profile and significance of data quality in the NHS by providing data submitters with aggregated information about their data quality. It displays data for all submitters and covers other submissions as well as DID. The first publication is a start point set to engage the health system in the quality of core data items. A copy of the index is held at:

How can I make an enquiry or provide feedback?

If you have an enquiry about DID, or would like to suggest how we can improve our web content, please contact the NHD Digital Contact Centre on 0845 300 6016 or by emailing

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