Lung Disease Trends in the UK, Before and After the COVID-19 Pandemic

Asthma, chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) affect more than 10 million people in the United Kingdom (England, Wales, Scotland and Northern Ireland), or approximately 15% of the population, but researchers believe a substantial number of diagnoses were missed during the COVID-19 pandemic.

A first-of-its-kind study headed by Hannah Whittaker, an inflammation and immunity research fellow at Imperial College London, aimed to show the burden of asthma, COPD and ILD in the U.K. over a 20-year period using harmonized electronic health records to pave the way for federated data analyses across the country.

The study, published in Thorax on April 8, 2025, utilized the health data from across England, Wales, Scotland and Northern Ireland to examine trends in the incidence and prevalence of asthma, COPD and ILD between 2004 and 2023.

Before the pandemic, new cases of asthma and COPD had decreased across most of the U.K., while the incidence of ILD significantly increased.

The study uncovered a significant dip in lung disease diagnoses during the COVID-19 pandemic. Comparing expected to actual rates, Whittaker and her colleagues estimated that only about a third of anticipated new asthma and COPD cases were diagnosed, and ILD diagnoses were nearly 50% lower than expected. This suggests a large number of people with respiratory issues were likely undiagnosed and untreated.

The researchers concluded that the incidence of asthma decreased, the incidence of ILD increased and the incidence of COPD has decreased only in England and Wales.

“Changes in incidence rates were likely due to changes in behaviors and disease awareness,” they wrote. “Disparities in incidence rates exist by sex, age, region, IMD (index of multiple deprivation) and ethnicity, and missed diagnoses from the COVID-19 pandemic could have a great impact on the future health of people with chronic respiratory diseases.”

The study found a long-term decline in asthma and COPD incidence in the U.K. before the pandemic, a significant increase in ILD incidence and a concerning drop in diagnoses for all three conditions during the pandemic, indicating a backlog of undiagnosed cases.