@Article{info:doi/10.2196/27342,
author="Nakanishi, Miharu
and Shibasaki, Ryosuke
and Yamasaki, Syudo
and Miyazawa, Satoshi
and Usami, Satoshi
and Nishiura, Hiroshi
and Nishida, Atsushi",
title="On-site Dining in Tokyo During the COVID-19 Pandemic: Time Series Analysis Using Mobile Phone Location Data",
journal="JMIR Mhealth Uhealth",
year="2021",
month="May",
day="11",
volume="9",
number="5",
pages="e27342",
keywords="COVID-19; mobility data; on-site dining; public health and social measures; public health; mobile phone; mobility; protection; time series; location; infectious disease; transmission",
abstract="Background: During the second wave of COVID-19 in August 2020, the Tokyo Metropolitan Government implemented public health and social measures to reduce on-site dining. Assessing the associations between human behavior, infection, and social measures is essential to understand achievable reductions in cases and identify the factors driving changes in social dynamics. Objective: The aim of this study was to investigate the association between nighttime population volumes, the COVID-19 epidemic, and the implementation of public health and social measures in Tokyo. Methods: We used mobile phone location data to estimate populations between 10 PM and midnight in seven Tokyo metropolitan areas. Mobile phone trajectories were used to distinguish and extract on-site dining from stay-at-work and stay-at-home behaviors. Numbers of new cases and symptom onsets were obtained. Weekly mobility and infection data from March 1 to November 14, 2020, were analyzed using a vector autoregression model. Results: An increase in the number of symptom onsets was observed 1 week after the nighttime population volume increased (coefficient=0.60, 95{\%} CI 0.28 to 0.92). The effective reproduction number significantly increased 3 weeks after the nighttime population volume increased (coefficient=1.30, 95{\%} CI 0.72 to 1.89). The nighttime population volume increased significantly following reports of decreasing numbers of confirmed cases (coefficient=--0.44, 95{\%} CI --0.73 to --0.15). Implementation of social measures to restaurants and bars was not significantly associated with nighttime population volume (coefficient=0.004, 95{\%} CI --0.07 to 0.08). Conclusions: The nighttime population started to increase after decreasing incidence of COVID-19 was announced. Considering time lags between infection and behavior changes, social measures should be planned in advance of the surge of an epidemic, sufficiently informed by mobility data. ",
issn="2291-5222",
doi="10.2196/27342",
url="https://mhealth.jmir.org/2021/5/e27342",
url="https://doi.org/10.2196/27342",
url="http://www.ncbi.nlm.nih.gov/pubmed/33886486"
}