Actions to reduce the risks for asthma which were taken during COVID-19 could have seen reductions in asthma attacks over the pandemic

A study from Centre members used primary care data to investigate the changes in risk factors before and after the COVID-19 pandemic which can lead to asthma attacks - such as smoking, having an asthma action plan, being prescribed with inhaled corticosteroids, and having an influenza vaccination. The study showed that there were positive changes in risk factors which may have influenced a reduction in asthma attacks during the pandemic.

Substantial reductions in asthma attacks during pandemic

During the early years of the COVID-19 pandemic, there were substantial reductions in asthma attacks, although the reasons for these drops were poorly understood. The researchers of this study aimed to understand how risk factors might have influenced the fall in asthma attacks seen. They used routinely collected primary care data to answer their question.

The study

The research team used pseudonymised primary care data from the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC), and accident and emergency (A&E) department and hospital admission data from GP records. Anyone who had a diagnosis of asthma by their GP and had been treated with asthma medication in the 12 months before the study began, or anyone who had a hospital admission for asthma were included in the analyses. Those who had opted out of record sharing were not included.

The team studied 4 years’ worth of data: January 1^st, 2019 to December 31^st 2022. This meant that the full year before the COVID-19 pandemic and the following three calendar years were included in the study.

The researchers wanted to find the numbers of people who had:

1. Asthma attacks
2. Prescriptions of prednisolone for asthma attacks
3. A&E department attendance for asthma
4. Hospital admission for asthma

and they wanted to match these people against the risk factors:

1. An asthma self-management plan being given
2. An asthma review in last 12 months
3. Prescriptions of ICS
4. Number of ICS prescriptions
5. Being a current smoker
6. Influenza vaccination
7. Pneumococcal polysaccharide vaccination (PPV) in those aged ≥65 years 
8. Consultation for one or more of upper (URTI) or lower respiratory tract infection (LRTI) or influenza-like illness (ILI).

The results

For those in the RSC database, people with asthma consisted of 6.8% in 2019, 6.9% in 2020, 7.3% in 2021, and 7.6% in 2022 of the total per year.

The proportion of people who had asthma attacks in 2019 (20.4%) reduced to 15.1% in 2020, to 15.5% in 2021 and to 18.5% in 2022.

Across the 4 years, there were increases in the proportion of people who had:

• Influenza vaccinations
• Asthma self-management plans
• Inhaled Corticosteroids (ICS) prescriptions
• Pneumococcal polysaccharide vaccination

There were reductions in the number of people who:

• Had an upper-respiratory tract infection
• Had a lower-respiratory tract infection
• Were smokers

Those who had an influenza-like illness increased from 2019 by 10.6% in 2020, then decrease by 47.5% in 2021 and 23.8% in 2022.

What does this mean?

The researchers found that people with asthma were less likely to have attacks if they:

• Had an asthma self-management plan
• Were partially rather than fully COVID-19 vaccinated

People who were PPV and seasonal flu-vaccinated, who took ICS, had asthma reviews, were Asian, lived in urban areas and in more deprived areas, were more likely to have asthma attacks.

While these results don’t indicate causality, this study has shown association between the changes in risk factors and the reduction in asthma attacks.

Mome Mukherjee was the lead author on this study. She said:

This first study, in over 7.5 million people, identified the modifiable risk factors that could help explain the reductions in asthma exacerbations during the COVID-19 pandemic. This information is important to prevent ill-health of people with asthma, especially in resource-limited health services, so that asthma exacerbations do not rebound to pre-pandemic levels.

Mome Mukherjee

Read the paper

This publication is available from The Lancet Regional Health - Europe

Cite as

Mukherjee M, Okusi C, Jamie G, Byford R, Ferreira F, Agarwal U, Weatherill D, Fletcher M, Quint JK, Bhuia MR, de Lusignan S, Sheikh A. Modifiable risk factors for asthma exacerbations during the COVID-19 pandemic: a population-based repeated cross-sectional study using the Research and Surveillance Centre primary care database. The Lancet Regional Health - Europe, Volume 42, 2024, 100938, ISSN 2666-7762, https://doi.org/10.1016/j.lanepe.2024.100938.