Substantial and persistent reduction in asthma attacks during COVID-19 pandemic

A paper published in The Lancet Regional Health – Europe reports that there was a substantial and persistent reduction in asthma attacks in England during the first 18 months of the COVID-19 pandemic.

Researchers from the Usher Institute / Asthma UK Centre for Applied Research led the study using the Optimum Patient Care Research Database (OPCRD). OPCRD is a regulated, licensed and anonymised clinical dataset from GP practices across the UK that, at the time of this study, consisted of almost 10 million patients from 792 practices.

The Study

The researchers designed and carried out a retrospective cohort study, identifying patients with asthma between 2010 and 2015. From those identified, the researchers restricted the cohort to those who had had at least one asthma attack between January 2016 and October 2021.

From almost 10 million patients in the database, 571,166 had asthma, and of those, 100,362 had at least one asthma attack between January 2016 and October 2021, with a total of 298,390 asthma attacks during that time.

Results

The researchers calculated the rate of asthma attacks by dividing the total number of asthma attacks each week by the number of patients who were in the cohort in that week. Before the pandemic, the rate of asthma attacks followed a seasonal pattern with peaks during the winter months and a drop during the summer. Even taking these seasonal fluctuations into account, overall, there was a consistent and substantial reduction in the rates of asthma attacks after the pandemic began compared to the rates during the pre-pandemic years.

Other than the first quarter of 2020, all the remaining quarters of 2020 and until quarter 3 of 2021 had a higher than 25% reduction in the rates of asthma attacks compared to the rates seen in the same quarters during 2016 -2019. These reductions were seen for males and females, all age groups and all regions across England and all the time periods studied.

Implications

Although this is the first and longest national-level study of the reduction in rates of asthma attacks since the beginning of the pandemic, further investigation is needed to understand the reasons behind this. The researchers believe that the most likely explanation is the reduced exposure to respiratory viruses such as rhinoviruses, which are common triggers of asthma attacks. This reduced exposure was likely due to the widespread adoption of pandemic-related measures such as mask-wearing, social distancing, and improved hygiene including frequent handwashing and cleaning of public places.

Dr Syed Ahmar Shah, the Usher Institute's Director of Innovation, was the lead author on this study. He believes that this study shows that a substantial reduction in asthma attacks is possible without using further pharmacological interventions (beyond what is currently available). He said:

The COVID-19 pandemic provided us with a unique window of opportunity to study the extent of reduction in asthma attacks that is possible with public health measures. This study provides a clear and compelling evidence of substantial and sustained reduction in asthma attacks. We believe that the key drivers that led to this decrease during the pandemic were reduced exposure to respiratory viruses and improved self-management. Going forward post pandemic, we must design and develop practical non-pharmacological measures that can continue to benefit people with asthma.

Dr Syed Ahmar Shah

Read the paper

This publication is available from The Lancet Regional Health Europe

Cite as

Shah SA, Quint JK, Sheikh A, Impact of COVID-19 pandemic on asthma exacerbations: Retrospective cohort study of over 500,000 patients in a national English primary care database. The Lancet Regional Health – Europe, 2022;00: 100428 https://doi.org/10.1016/j.lanepe.2022.100428   

Previous publication

This study extends work completed by the researchers in 2020 which identified a 20% reduction in asthma attacks during the first COVID-19 lockdown. See more:

Lockdown linked to drop in asthma exacerbations, GP data suggests

Optimum Patient Care Research Database

Find out more about Optimum Patient Care and the OPCRD:

Optimum Patient Care website

Asthma UK Centre for Applied Research

A UK-wide network of world-leading academics and partners, working collaboratively to improve treatment and care for people living with asthma. Led by Directors Professor Sir Aziz Sheikh of the University of Edinburgh, and Professor Chris Griffiths of Queen Mary University of London.

Asthma UK Centre for Applied Research