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Assessing the regional impact of Japan's COVID-19 state of emergency declaration: a population-level observational
Daisuke Yoneoka1,2,3, Shoi Shi4,5, Shuhei Nomura1,3
1Department of Health Policy and Management, School of Medicine, Keio University, Tokyo, Japan.
Objective:
On 7 April 2020, the Japanese government declared a state of emergency in response to the novel coronavirus outbreak. To estimate the impact of the declaration on regional cities with low numbers of COVID-19 cases, large-scale surveillance to capture the current epidemiological situation of COVID-19 was urgently conducted in this study.
Design:
Cohort study.
Setting:
Social networking service (SNS)-based online survey conducted in five prefectures of Japan: Tottori, Kagawa, Shimane, Tokushima and Okayama.
Participants:
127 121 participants from the five prefectures surveyed between 24 March and 5 May 2020.
Interventions:
An SNS-based healthcare system named COOPERA (COvid-19: Operation for Personalized Empowerment to Render smart prevention And care seeking) was launched. It asks questions regarding postcode, personal information, preventive actions, and current and past symptoms related to COVID-19.
Primary And Secondary Outcome Measures:
Empirical Bayes estimates of age-sex-standardised incidence rate (EBSIR) of symptoms and the spatial correlation between the number of those who reported having symptoms and the number of COVID-19 cases were examined to identify the geographical distribution of symptoms in the five prefectures.
Results:
97.8% of participants had no subjective symptoms. We identified several geographical clusters of fever with significant spatial correlation (r=0.67) with the number of confirmed COVID-19 cases, especially in the urban centres of prefectural capital cities.
Conclusions:
Given that there are still several high-risk areas measured by EBSIR, careful discussion on which areas should be reopened at the end of the state of emergency is urgently required using real-time SNS system to monitor the nationwide epidemic.
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