COVID-19 clinical risk groups cohort 2023: Cohort identification methodology

NHS England's Vaccination and Screening Directorate has commissioned the NHS England Vaccine Digital Service (VDS) to flow patient identifiable data to be used for call/recall, monitoring and reporting for the COVID-19 clinical risk groups as defined in tables 3 and 4 of the Green Book chapter 14a.

NHS England’s Vaccination programme has commissioned NHS England’s Cohorting as a Service (CaaS) to provide patient identifiable cohorts for these clinically at risk groups.

The clinical at-risk groups within scope of this digital cohort development (as specified by NHS England) are:

Adults aged 16 years and over:

• chronic respiratory disease
• chronic heart disease and vascular disease
• chronic kidney disease
• chronic liver disease
• chronic neurological disease
• Diabetes mellitus and other endocrine disorders
• Immunosuppression
• Asplenia or dysfunction of the spleen
• morbidly obese
• severe mental illness

Children 6 months to 15 years of age:

• chronic respiratory disease
• chronic heart conditions
• chronic conditions of the kidney, liver, or digestive system
• chronic neurological disease
• Endocrine disorders

• Immunosuppression

• Asplenia or dysfunction of the spleen 

• serious genetic abnormalities that affect a number of systems

Age based cohorting

• people aged 65 years or over on 31 March 2024

This document outlines NHS England’s Cohorting as a Service's (CaaS) approach to deliver this cohort using established methodologies. It also highlights any divergence from the clinical criteria held within tables 3 and 4 of Chapter 14a of the Green Book and associated assumptions.