Code list used for population risk assessment

NHS Digital used QCovid® to develop the COVID-19 Population Risk Assessment. which combined a number of factors such as age, sex registered at birth, ethnicity, body mass index (BMI) and specific health conditions and treatments to estimate the risk of a person catching coronavirus and becoming seriously unwell.

Centrally held patient data was used to identify people who might be at high risk, using the codes listed in the document below. Using data in this way for the COVID-19 Population Risk Assessment provided ongoing opportunities for improvements in care through identification of particular cohorts of patients in primary care.

The University of Oxford’s QCovid® model was developed using the QResearch database, which includes anonymised GP record data and uses SNOMED-CT codes and Read v2 codes. To allow the model to be applied at a population level, an expanded list of SNOMED-CT codes was produced. This expanded list of codes was used to implement the COVID-19 Population Risk Assessment but was not used in the research to develop the model. Read more about some of these expanded code sets.

This was in line with the precautionary approach to be as inclusive as possible and overestimate rather than underestimate risk and helped to ensure that people who may be at high risk from coronavirus received advice, priority access to vaccination and other support available to people added to the Shielded Patient List (SPL).

QCovid® Risk Calculator DLL v1.1.0 was used for the COVID-19 Population Risk Assessment.  

• Ethnic category coverage
• GDPR:GPES data for pandemic planning and research (COVID-19)*
• GPES (General Practice Extraction Service) v3: COVID-19 at risk patients data collection version 3*
• HES: Hospital Episodes Statistics datasets
• PDS: Personal Demographics Service
• RTDS: Radiotherapy Dataset
• SACT: Systematic Anti-Cancer Therapy dataset

*The code list document describes GPES and GDPPR collectively as GP data, as the coding in these datasets is the same

• Chemotherapy A: Chemotherapy in the last 12 months, category A drugs as defined by QCovid®
• Chemotherapy B: Chemotherapy in the last 12 months, category B drugs as defined by QCovid®
• Chemotherapy C:Chemotherapy in the last 12 months, category C drugs as defined by QCovid®
• DM+D The NHS Dictionary of Medicines and Devices
• IC10: International Statistical Classification of Diseases and Related Health Problems 10th Revision 
• N/A: non standard coding system: used for ethnic category and sex
• OPCS: OPCS Classification of Interventions and Procedures version 4
• SNOMED CT: Systemised Nomenclature of Medicine 

The Townsend score is a measure of material deprivation based on the area where a person lives and obtained using their postcode. It includes four variables obtained from census data: unemployment (lack of material resources and insecurity), overcrowding (material living conditions), lack of owner-occupied accommodation (a proxy indicator of wealth) and lack of car ownership (a proxy indicator of income).  

The Townsend scores for QCovid® were based on the Townsend algorithm and data from the ONS census. It is possible to recreate the scores using the algorithm, data and with the same approach to rounding. More information is available in the report UK Townsend Deprivation Scores from 2011 census data