RT Journal Article SR Electronic T1 Real-world retrospective database analysis of COPD exacerbations before and during the COVID-19 pandemic in Europe (REACT) JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 4405 DO 10.1183/13993003.congress-2022.4405 VO 60 IS suppl 66 A1 D Galkin A1 A Guasconi A1 J Imperato A1 R Hermans A1 S Pirondi A1 G Georges YR 2022 UL http://erj.ersjournals.com/content/60/suppl_66/4405.abstract AB Introduction: Several studies have reported a decline in the number of acute exacerbations of COPD (AECOPD) during the COVID-19 pandemic in 2020-21, likely a result of mask-wearing and social distancing. Clinical trials designed to assess the effect of therapeutic interventions on rates of AECOPD are usually enriched with a population having documented AECOPD during the prior year and thus may be impacted by this phenomenon.Objective: To quantify patients experiencing AECOPD during the COVID-19 pandemic, informing the feasibility of upcoming trials in Europe.Methods: A retrospective real-world data cohort analysis using IQVIA E360® was conducted on electronic medical records collected from France, Germany, Italy, and the UK. Patients with AECOPD were selected by a validated algorithm (Rothnie K.J. et.al. PLoS ONE 2016;11:e0151357). The proportion of patients with AECOPD were calculated for pre-COVID (Jan 2017-Dec 2019) and COVID periods (Jan 2020-Dec 2020).Results: Compared with 2019, the proportion of patients with AECOPD decreased in 2020 by an absolute 17-53% (45% to 28% in Germany, 51% to 27% in France, 63% to 17% in Italy, and 67% to 14% in the UK). In each country, the seasonal exacerbation pattern was no longer seen in 2020. Also, in Italy, France, and the UK, more patients filled prescriptions for maintenance COPD treatment during the pandemic than before.Conclusions: The proportion of patients with AECOPD were substantially decreased during the pandemic with flattening of the seasonal pattern. These findings are likely to have a significant impact on the feasibility of enrichment strategies in clinical trials initiated in Europe in 2021.FootnotesCite this article as Eur Respir J 2022; 60: Suppl. 66, 4405.This article was presented at the 2022 ERS International Congress, in session “-”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).