Graduate School of Environmental Studies, Tohoku University.
ALBERT Inc.
J Epidemiol. 2021 Jun 5;31(6):387-391. doi: 10.2188/jea.JE20200625. Epub 2021 Apr 23.
As the COVID-19 pandemic spread, the Japanese government declared a state of emergency on April 7, 2020 for seven prefectures, and on April 16, 2020 for all prefectures. The Japanese Prime Minister and governors requested people to adopt self-restraint behaviors, including working from home and refraining from visiting nightlife spots. However, the effectiveness of the mobility change due to such requests in reducing the spread of COVID-19 has been little investigated. The present study examined the association of the mobility change in working, nightlife, and residential places and the COVID-19 outbreaks in Tokyo, Osaka, and Nagoya metropolitan areas in Japan.
First, we calculated the daily mobility change in working, nightlife, and residential places compared to the mobility before the outbreak using mobile device data. Second, we estimated the sensitivity of mobility changes to the reproduction number by generalized least squares.
Mobility change had already started in March, 2020. However, mobility reduction in nightlife places was particularly significant due to the state of emergency declaration. Although the mobility in each place type was associated with the COVID-19 outbreak, the mobility changes in nightlife places were more significantly associated with the outbreak than those in the other place types. There were regional differences in intensity of sensitivity among each metropolitan area.
Our findings indicated the effectiveness of the mobility changes, particularly in nightlife places, in reducing the outbreak of COVID-19.
随着 COVID-19 疫情的蔓延，日本政府于 2020 年 4 月 7 日对七个县宣布进入紧急状态，并于 2020 年 4 月 16 日对所有县宣布进入紧急状态。日本首相和各地方长官要求民众采取自我克制行为，包括在家办公和避免光顾夜生活场所。然而，这种请求导致的出行变化对减少 COVID-19 传播的有效性尚未得到充分研究。本研究考察了日本东京、大阪和名古屋大都市地区工作、夜生活和居住场所出行变化与 COVID-19 疫情爆发之间的关系。
首先，我们使用移动设备数据计算了与疫情爆发前相比工作、夜生活和居住场所的日常出行变化。其次，我们通过广义最小二乘法估计了出行变化对繁殖数的敏感性。
出行变化早在 2020 年 3 月就已经开始。然而，由于宣布进入紧急状态，夜生活场所的出行减少尤其显著。尽管每种场所类型的出行都与 COVID-19 疫情爆发有关，但夜生活场所的出行变化与疫情爆发的相关性比其他场所类型更为显著。每个大都市地区之间的敏感性强度存在区域差异。
我们的研究结果表明，出行变化，特别是夜生活场所的出行变化，对减少 COVID-19 疫情爆发具有有效性。
