TY - JOUR T1 - Changes in respiratory diseases in South Korea during the COVID-19 pandemic: an interrupted time series study JF - BMJ Global Health JO - BMJ Global Health DO - 10.1136/bmjgh-2021-006912 VL - 6 IS - 12 SP - e006912 AU - Seog-Kyun Mun AU - Bo Ram Yang AU - Munyoung Chang Y1 - 2021/12/01 UR - http://gh.bmj.com/content/6/12/e006912.abstract N2 - Introduction In South Korea, non-pharmaceutical interventions such as mask-wearing, hand washing and social distancing were strictly implemented to prevent the spread of COVID-19 after a national crisis alert was raised to the highest level early in the pandemic (23 February 2020). We aimed to investigate changes in the occurrence of respiratory diseases at the national level after the COVID-19 outbreak.Methods The study period was from 1 January to 1 August 2019 (213 days) and from 1 January to 31 July 2020 (213 days). Based on the National Health Insurance Service data, we analysed changes in the numbers of patients treated for respiratory diseases. The changes in the numbers of individuals using public transportation and visiting the theatre were investigated to assess the effect of social distancing after the national crisis alert was raised. Differences in daily cumulative numbers (DDCNs) in 2020 were calculated as follows: (daily cumulative number in 2020)–(cumulative number for that day in 2019). A change over time in DDCNs of <0 was taken as indication that the numbers decreased from 2019 to 2020. Segmented regression analyses were performed using generalised least squares method to identify changes in trends of DDCNs of patients treated for respiratory diseases and individuals using public transportation and visiting the theatre.Results After the national crisis alert was raised to the highest level, DDCNs of patients treated for respiratory diseases, individuals using public transportation, and those visiting the theatre exhibited a significant daily decline by 53.18 per 10 000 inhabitants (95% CI −65.86 to −40.49), 48.19 per 1000 inhabitants (95% CI −62.05 to −34.32) and 25.30 per 5000 inhabitants (95% CI −36.30 to −14.30), respectively, compared with before the national crisis alert was raised.Conclusion Non-pharmaceutical interventions to prevent the spread of COVID-19 significantly reduce the incidence of respiratory diseases.Data are available upon reasonable request. This study used NHIS data made by National Health Insurance Service (NHIS). The data used in this study are available from the Public Data Portal website operated by the Korea Information Society Agency (https://www.data.go.kr/), Korean Statistical Information Service website operated by Statistics Korea (https://kosis.kr/index/index.do), Transportation Card Big Data Integrated Information System operated by the Ministry of Land, Infrastructure and Transport and the Korea Transportation Safety Authority (https://www.stcis.go.kr/wps/main.do%23), and Korean box-office information system operated by the Korean film council (https://www.kobis.or.kr/kobis/business/stat/them/findDailyTotalList.do). ER -