Reduction of Severe Exacerbations of COPD during COVID-19 Pandemic in Portugal: A Protective Role of Face Masks?

Viral infections are known to be the main trigger for Chronic obstructive pulmonary disease (COPD) exacerbations. Face masks are acknowledged for effective viral aerosol shedding reduction. COVID-19 pandemic generated an opportunity to study the impact of face masks and confinement on droplet transmission diseases, usually implicated in acute exacerbations of COPD (AECOPD). We aimed to evaluate the variation on severe AECOPD (sAECOPD) rate in a Portuguese COPD cohort during the first COVID-19 lockdown and following months. This retrospective self-controlled study enrolled 322 adult patients followed at COPD-specialized consultation in a tertiary hospital from February 2016 to July 2020, of whom 286 met inclusion criteria. Severe AECOPD events were registered from March 2020 (beginning of state of emergency) until July 2020. From 2016 to 2019 there was a mean of 38 patients per year with sAECOPD. During 2020, 11 patients experienced sAECOPD. Over the course of 2020 there was a 73.4% (p < 0.001) decrease in sAECOPD events comparing with previous years' average. After the end of State of Emergency, the rate of sAECOPD events also declined by 74.6% (p < 0.001) comparing with the same timeline of previous years. Results were consistent and statistically significant when comparing 2020 with each of previous years for every period of analysis. Our findings suggest a sustained decrease in the rate of sAECOPD during confinement and in the following months. The widespread use of face mask and social distancing during COVID-19 pandemic may play an important role in preventing the transmission of respiratory infections and consequently reducing sAECOPD.