Reduction in COPD exacerbations during COVID-19: a systematic review and meta-analysis

Background Reports have suggested a reduction in exacerbations of chronic obstructive pulmonary disease (COPD) during the coronavirus (COVID-19) pandemic, particularly hospital admissions for severe exacerbations. However, the magnitude of this reduction varies between studies. Method Electronic databases were searched from January 2020 to May 2021. Two independent reviewers screened titles and abstracts and, when necessary, full text to determine if studies met inclusion criteria. A modified version of the Newcastle-Ottawa Scale was used to assess study quality. A narrative summary of eligible studies was synthesised, and meta-analysis was conducted using a random effect model to pool the rate ratio and 95% confidence intervals (95% CI) for hospital admissions. Exacerbation reduction was compared against the COVID-19 Containment and Health Index. Results A total of 13 of 745 studies met the inclusion criteria and were included in this review, with data from nine countries. Seven studies could be included in the meta-analysis. The pooled rate ratio of hospital admissions for COPD exacerbations during the pandemic period was 0.50 (95% CI 0.42-0.58). Findings on the rate of community-treated exacerbations were inconclusive. Three studies reported a significant decrease in the incidence of respiratory viral infections compared with the pre-pandemic period. There was not a significant relationship between exacerbation reduction and the COVID-19 Containment and Health Index. Conclusion There was a 50% reduction in admissions for COPD exacerbations during the COVID-19 pandemic period, associated with a reduction in respiratory viral infections that trigger exacerbations. We provide pooled evidence supporting the potential effectiveness of COVID-19 preventive interventions in reducing the risk of admissions for COPD exacerbations.