We have detected that you are using Internet Explorer to visit this website. Internet Explorer is now being phased out by Microsoft. As a result, NHS Digital no longer supports any version of Internet Explorer for our web-based products, as it involves considerable extra effort and expense, which cannot be justified from public funds. Some features on this site will not work. You should use a modern browser such as Edge, Chrome, Firefox, or Safari. If you have difficulty installing or accessing a different browser, contact your IT support team.
How we created the Shielded Patient List
Mark Reynolds, Interim Chief Technology Officer at NHS Digital, explains the architecture behind the NHS Shielded Patient List, which is helping to protect the most vulnerable members of society during the coronavirus pandemic.
- Author:
- Date:
-
17 November 2020

On 21 March 2020 it was announced that people at highest risk of complications from coronavirus (COVID-19) would need to shield themselves from society. We needed a way to quickly identify and inform this group of people so they could take immediate action to help protect themselves.
We created the NHS Shielded Patient List to provide a record of these people identified from GP and hospital (HES) data.
The service initially went live on 20 March 2020 and grew in scope in response to the COVID-19 pandemic, allowing those identified to be at risk to receive care support, food parcels and preferential access to online delivery from the supermarkets.
The diagram shows how the Shielded Patient List combines the Data Management Environment (DME) and Data Processing Service (DPS) data and uses data flow and extraction technologies (for example, Messaging Exchange Health and Social Care (MESH) and the General Practice Extraction Service (GPES)) to obtain clinical data.
The clinical data is taken from a patient’s GP record and demographic information (including name, date of birth and address) is taken from the Master Patient Service (also known as the Master Person Service) on the left-hand side. The data is used with a set of rules to determine which patients are at highest risk.
The “product” is the actual Shielded Patient List service (top yellow boxes) and the list is sent to other organisations such as Public Health England via the Secure Electronic File Transfer and other mechanisms shown on the right (the Shielded Patient List viewer and the Shielding Note Service).
The black box indicates the external Gov.UK Notify service which was used to contact those at risk to inform them that they were on the list and needed to shield.
Alongside these new flows, the Shielded Patient List also uses data sets already held by NHS Digital, for example the Maternity Services Data Set.
3. Additions and deduction requests from GPs and hospital doctors are recorded.
4. The individual rules are combined to identify who should be on the list with rules dealing with changes in conditions, requests for additions and deductions, code deletion and so forth.
5. The final list is checked to remove deceased patients – there is a human check on data quality and then is approved for release.
Related subjects
-
This document describes the methodology that has been used to identify patients who meet the high risk criteria for contracting coronavirus (COVID-19), due to their inclusion in one or more of the identified disease groups
-
NHS Digital has published the Shielded Patient List (SPL), which is enabling partner organisations across government to support and protect those who need shielding at this time.
-
The coronavirus (COVID-19) shielded patient list is enabling partner organisations across government to support and protect those who need shielding at this time. This data shows open data about the Shielded Patient List, and how it has been used.