Rebound in asthma exacerbations following relaxation of COVID-19 restrictions: a longitudinal population-based study (COVIDENCE UK)

Abstract

Background: The imposition of restrictions on social mixing early in the COVID-19 pandemic was followed by a reduction in asthma exacerbations in multiple settings internationally. Temporal trends in social mixing, incident acute respiratory infections (ARI) and asthma exacerbations following relaxation of COVID-19 restrictions have not yet been described.

Methods: We conducted a population-based longitudinal study in 2312 UK adults with asthma between November 2020 and April 2022. Details of face covering use, social mixing, incident ARI and severe asthma exacerbations were collected via monthly online questionnaires. Temporal changes in these parameters were visualised using Poisson generalised additive models. Multilevel logistic regression was used to test for associations between incident ARI and risk of asthma exacerbations, adjusting for potential confounders.

Results: Relaxation of COVID-19 restrictions from April 2021 coincided with reduced face covering use (p<0.001), increased frequency of indoor visits to public places and other households (p<0.001) and rising incidence of COVID-19 (p<0.001), non-COVID-19 ARI (p<0.001) and severe asthma exacerbations (p=0.007). Incident non-COVID-19 ARI associated independently with increased risk of asthma exacerbation (adjusted OR 5.75, 95% CI 4.75 to 6.97) as did incident COVID-19, both prior to emergence of the omicron variant of SARS-CoV-2 (5.89, 3.45 to 10.04) and subsequently (5.69, 3.89 to 8.31).

Conclusions: Relaxation of COVID-19 restrictions coincided with decreased face covering use, increased social mixing and a rebound in ARI and asthma exacerbations. Associations between incident ARI and risk of severe asthma exacerbation were similar for non-COVID-19 ARI and COVID-19, both before and after emergence of the SARS-CoV-2 omicron variant.

Study registration number: NCT04330599.

Keywords: Asthma; COVID-19.

Figure 1

Participant flow.

Figure 2

Temporal trends in behaviours potentially influencing risk of acquiring or transmitting acute respiratory infections from November 2020 to April 2022. (A) Proportion of participants using a face covering 100% of the time when visiting an indoor public place in the week prior to completion of monthly follow-up questionnaire. (B) Proportion of participants visiting shops at least once in the week prior to completion of monthly follow-up questionnaire. (C) Proportion of participants visiting an indoor public place other than a shop at least once in the week prior to completion of monthly follow-up questionnaire. (D) Proportion of participants making or receiving at least one indoor visit to another household in the week prior to completion of monthly follow-up questionnaire. (E) Proportion of participants using public transport at least once in the week prior to completion of monthly follow-up questionnaire. (F) Proportion of participants travelling outside the UK at least once in the month prior to completion of monthly follow-up questionnaire. All plots are from univariable generalised additive models; p values refer to temporal changes in proportions over the study period. Solid and dotted lines show means and 95% CIs, respectively.

Figure 3

Temporal trends in incident acute respiratory infections and asthma exacerbations from November 2020 to April 2022. (A) RT-PCR-confirmed or antigen test-confirmed COVID-19. (B) Episodes of acute respiratory infection symptoms associated with a negative RT-PCR or antigen test result for SARS-CoV-2. (C) Episodes of severe asthma exacerbation. All plots are from univariable generalised additive models; p values refer to temporal changes in proportions over the study period. Solid and dotted lines show means and 95% CIs, respectively.