. 2021 Mar 11;21:484. doi: 10.1186/s12889-021-10427-2

Table 1.

COVID-19 moderate- and high-risk groups in national guidance [7] compared to the at-risk population study definition

COVID-19 moderate- and high-risk population definitions in national guidance for England [7]	Study definition
Anyone aged 70 years or older (regardless of medical conditions) is defined as at moderate risk.	The study definition of the at-risk population for all ages comprised individuals with any of the underlying health conditions in national guidance, incorporating high risk groups as indicated. Detailed inclusion criteria for each condition were based on national guidance defining influenza clinical risk groups, to reflect risk of respiratory infection [8].
Among individuals aged less than 70 years, people at moderate risk from coronavirus infection include people who: • have a lung condition that’s not severe (such as asthma, chronic obstructive pulmonary disease, emphysema or bronchitis) o high risk have been told by a doctor they have a severe lung condition (such as cystic fibrosis, severe asthma or severe chronic obstructive pulmonary disease) • have heart disease (such as heart failure) • have diabetes • have chronic kidney disease • have liver disease (such as hepatitis) • have a condition affecting the brain or nerves (such as Parkinson’s disease, motor neurone disease, multiple sclerosis or cerebral palsy) • have a condition that means they have a high risk of getting infections o high risk have a condition that means they have a very high risk of getting infections (such as SCID or sickle cell) o high risk have blood or bone marrow cancer (such as leukaemia, lymphoma or myeloma) • are taking medicine that can affect the immune system (such as low doses of steroids) o high risk are taking medicine that makes them much more likely to get infections (such as high doses of steroids or immunosuppressant medicine) o high risk have had an organ transplant o high risk are having chemotherapy or antibody treatment for cancer, including immunotherapy o high risk are having an intense course of radiotherapy (radical radiotherapy) for lung cancer o high risk are having targeted cancer treatments that can affect the immune system (such as protein kinase inhibitors or PARP inhibitors) o high risk have had a bone marrow or stem cell transplant in the past 6 months, or are still taking immunosuppressant medicine • are very obese (a BMI of 40 or above)
• are pregnant o high risk have a serious heart condition and are pregnant	The prevalence of pregnancy was estimated separately from the general at-risk population.

COVID-19 moderate- and high-risk population definitions in national guidance for England [7]

Study definition

Anyone aged 70 years or older (regardless of medical conditions) is defined as at moderate risk.

The study definition of the at-risk population for all ages comprised individuals with any of the underlying health conditions in national guidance, incorporating high risk groups as indicated.

Detailed inclusion criteria for each condition were based on national guidance defining influenza clinical risk groups, to reflect risk of respiratory infection [8].

Among individuals aged less than 70 years, people at moderate risk from coronavirus infection include people who:

• have a lung condition that’s not severe (such as asthma, chronic obstructive pulmonary disease, emphysema or bronchitis)

o high risk have been told by a doctor they have a severe lung condition (such as cystic fibrosis, severe asthma or severe chronic obstructive pulmonary disease)

• have heart disease (such as heart failure)

• have diabetes

• have chronic kidney disease

• have liver disease (such as hepatitis)

• have a condition affecting the brain or nerves (such as Parkinson’s disease, motor neurone disease, multiple sclerosis or cerebral palsy)

• have a condition that means they have a high risk of getting infections

o high risk have a condition that means they have a very high risk of getting infections (such as SCID or sickle cell)

o high risk have blood or bone marrow cancer (such as leukaemia, lymphoma or myeloma)

• are taking medicine that can affect the immune system (such as low doses of steroids)

o high risk are taking medicine that makes them much more likely to get infections (such as high doses of steroids or immunosuppressant medicine)

o high risk have had an organ transplant

o high risk are having chemotherapy or antibody treatment for cancer, including immunotherapy

o high risk are having an intense course of radiotherapy (radical radiotherapy) for lung cancer

o high risk are having targeted cancer treatments that can affect the immune system (such as protein kinase inhibitors or PARP inhibitors)

o high risk have had a bone marrow or stem cell transplant in the past 6 months, or are still taking immunosuppressant medicine

• are very obese (a BMI of 40 or above)

• are pregnant

o high risk have a serious heart condition and are pregnant

The prevalence of pregnancy was estimated separately from the general at-risk population.