Social distancing during the COVID-19 pandemic: Potential impact and correlation with asthma

Background: Non-pharmaceutical interventions have been implemented globally to control the COVID-19 pandemic and have been shown to alleviate both allergies and respiratory infections. Although mask-wearing is an accepted non-pharmaceutical intervention, the effects of social distancing have not been thoroughly evaluated. Objectives: To evaluate the effects of social distancing on asthma trends in Seoul, South Korea. Methods: This study included data from the National Health Insurance Service of South Korea, covering approximately 10 million people in Seoul. Daily and monthly data of patients with asthma from 2018 to 2021 were examined, and the degree of social distancing performance was measured using the number of subway users as an index. Pearson's correlation coefficient was used to determine the relationship between the two indices. The change-point detection technique, cross-correlation, and Granger causality method were used to assess the temporal causality between social distancing and asthma. Results: The number of patients with asthma decreased by 42.4 % from 2019 to 2020, while that of subway users decreased by 26.3 % during this period. Pearson's correlation analysis revealed significant positive correlations. Asthma and subway users showed a significant change in incidence following the implementation of social distancing; subway users showed a causal relationship with patients with asthma. Conclusion: Our results showed that the number of subway users decreased after the implementation of strict social distancing, coinciding with a decrease in the number of patients with asthma. These findings suggest that social distancing measures implemented to control COVID-19 may reduce the incidence and exacerbation of asthma.