Using codelists with NHS England data#
Last modified: 01 Apr 2025
Which NHS England datasets require researchers to provide a codelist?#
Six of the 19 NHS England datasets in the UK LLC TRE require a clinical code list. These datasets are:
What is a codelist?#
A codelist is a list of medical codes (e.g. SNOMED CT, ICD-10) which pertain to a research question. The coding systems used by each dataset are outlined on the Coded variables page.
Why do researchers need to provide a codelist for some datasets?#
Data from Electronic Health Records have to be minimised to relevant medical codes before being made available to researchers. Providing researchers with only those records that are relevant to their research both reduces disclosure risk and ensures the project’s scope remains as approved by UK LLC’s application process.
What should a codelist look like?#
UK LLC provides a codelist template as a downloadable MS Excel file. The template contains information on which coding systems should be used for each of the NHS England datasets.
How do I create a codelist?#
There are online repositories of codelists generated by researchers who have used electronic health records. The following resources may be of particular use:
What happens if I need to update my codelist during my project?#
If you need to add more clinical codes without changing the scope of the project, you can email a new codelist to support@ukllc.ac.uk, explaining why the codelist has changed.
If you need to add clinical codes that are outside the original project scope, you should submit an amendment via UK LLC Apply.