Risk of COVID-19 hospital admission among children aged 5–17 years with asthma in Scotland: a national incident cohort study

November 2021: Research published in The Lancet Respiratory Medicine looks at the risk of children with asthma in Scotland being admitted to hospital with COVID-19.

Summary in Plain English

Which groups of people should be prioritised for COVID-19 vaccination is a key question for patients and their family and friends, policy makers and healthcare professionals.

When the Pfizer-BioNTech vaccine was first offered to people under 18 on the advice of the Joint Committee for Vaccination and Immunisation (JCVI), children aged 12-15 with the following conditions were prioritised for vaccination:

• Severe disabilities affecting the nerves and brain (neuro-disabilities)
• Down’s syndrome
• A lowered immune system
• Multiple or severe learning disabilities

Although there is evidence that adults with asthma in Scotland are at higher risk of serious complications from COVID-19, research on children with asthma is limited and no prioritisation was given for this group.

Why did we carry out this research?

We wanted to give population-wide evidence to the JCVI on the risk of serious COVID-19 outcomes for children with asthma in Scotland. This is the first national-scale study to look at this question.

Asthma is a common condition in the UK which can cause wheezing, coughing and difficulty breathing. Uncontrolled asthma can require treatment with steroids or hospital admission.

Because asthma is so common, we wanted to understand whether certain children with asthma were at higher risk than others of becoming seriously ill with COVID-19.

This should help to inform which children with asthma might be prioritised or encouraged to have one or more doses of a COVID-19 vaccine in the future.

What data did we use?

We analysed GP and hospital records, death records, virus testing data, existing COVID-19 risk groups, and information like age, sex and location, linked together securely in the EAVE II platform.

Find out more about EAVE II

We identified all people aged 5-17 in the data from 1 March 2020, which includes 752,867 children and young people. We analysed data from this group until 27 July 2021.

We defined COVID-19 hospitalisation as anyone admitted to hospital with a diagnosis of COVID-19, or within 14 days of a positive COVID-19 PCR (‘polymerase chain reaction’) test. This included people who tested positive in hospital. The number of deaths in children and young people with asthma was too small (less than 5 people) for us to carry out any analysis on risk of death from COVID-19.

We also wanted to compare COVID-19 risks for children and young people with asthma that is well or not well controlled.

To do this, we looked at whether people had been admitted to hospital with asthma, or had been given one or more courses of oral steroids, in the two years before the study started. We compared these groups to children and young people with no asthma.

What did we find?

Confirmed COVID-19 infection

In the group studied, 8.4% had asthma diagnosed and recorded by a doctor. Of these 63,463 children and young people, 4,339 (6.8%) had COVID-19 confirmed by PCR test in the study period.

67 children in this group (1.5%) were admitted to hospital for COVID-19.

Risk of being admitted to hospital for COVID-19

We found that the following groups were more likely to be admitted to hospital for COVID-19:

1. Children with a previous history of hospital admission for asthma were over six times more likely to be admitted than children without asthma. They were also over four times more likely to be admitted than children with better controlled asthma.
2. Children having two or more courses of prescribed oral steroids in the previous two years were three times more likely to be hospitalised than children not on oral steroids for the same period.
3. Children with poorly controlled asthma were more likely to be tested for, and admitted to hospital with, COVID-19. This is compared to both children without asthma and with better controlled asthma.

The risk levels did not change when we focused on children aged 12-15, who are currently being vaccinated.

What does this mean?

This research shows that children aged 5-17 are at 3 to 6 times higher risk of being admitted to hospital with COVID-19 if their asthma is not controlled, compared to those with no asthma.

This is equivalent to 9,124 children in Scotland, including 1,962 people aged 12-15.

When scaled up across the rest of the UK, there are over just under 110,000 children with uncontrolled asthma who should be considered a priority for COVID-19 vaccination. This includes 23,544 children aged 12-15.

As the pandemic progresses, we will continue to monitor the safety, effectiveness and uptake of vaccines in children and young people.

Learn more about our asthma research on the Asthma UK Centre for Applied Research website

Note

This plain English summary was created with the support and feedback of the EAVE II Public Advisory Group (PAG). This summary in particular was reviewed by Emily L and Sandra J.

To learn more about the PAG, see: Our EAVE II Public Advisory Group (PAG) | The University of Edinburgh

University of Edinburgh Press Release