東北大学研究新型コロナウイルス対応特別研究プロジェクト「ポストコロナ社会構築研究スタートアップ支援」

新型コロナウィルス対応における移動制限とその効果・影響の分析
Examining impacts of moving restrictions against the novel coronavirus epidemics

活動報告・研究成果の概要➋ 個人の生活行動変化の社会科学的分析-●-

目的 外出自粛要請（日本モデル）の評価と検証

2020年4月に実施された緊急事態宣言では外出自粛要請によって、人の動き（モビリティ）を減らし、流行を制御しようと試みた
その感染拡大防止の効果と社会的影響とは何であったか。

緊急事態宣言と関連した外出行動の大幅な減少をオンライン調査で確認（2A)

女性、低所得、非就労、公共交通利用、慢性疾患あり等の属性で外出抑制が大-外出に対する世間の目を気にすることも、外出抑制と関連-

iphoneヘルスケアアプリの記録から、大都市圏・若年層で歩行量や外出の大きな減少 (2B)-

身体活動の低下、座位時間の増加、メンタルヘルスの低下なども地域特性と関連➊ 人の動きと感染拡大の統計科学的分析-流行推移と人の動きの関連：

流行の時空間推移の可視化からも確認（1A)

モバイル空間統計を活用し、各都市で共通する人々の滞留人口変化のパターンを特定・都市の類型化(1B)「夜の街」型のメッシュ（1C)の滞留人口の変化が感染拡大率と強く関連することを統計学的に確認(1D)

2A: 緊急事態宣言と外出行動の推移

2B: 緊急事態宣言と歩数の推移➌ 感染拡大防止効果の情報科学的検討-

1B: 都市別のモビリティパターン推移

1A: COVID-19時空間密度-

強制力の無い感染抑制が有効な流行制御戦略となりうることの理論疫学的検討（単純ケースとして、１回の介入の場合の数理的解析・シミュレーション）(3A)
感染者数を最も少なく抑えられる適度な介入タイミングと強度があり、強すぎる介入は人々の社会生活に大きな影響を及ぼすのみならず、感染拡大防止の観点からも最善でないと示唆（3B)

1C: 「夜の街」型地区の推定
3A: タイミングの異なる介入効果のシミュレーション●-

1D 「夜の街」型地区の滞留人口推移とCOVID-19再生産数-

結論

3B: 介入強度と流行抑制効果

非強制的でない外出抑制である「日本モデル」が、2020年4月の緊急事態宣言では、モビリティ抑制を通して感染制御に有効であった。
一方で、外出抑制が困難であった人々、外出抑制によって影響を大きく受けた人々が地域特性に応じて存在したことを確認した。

東北大学研究新型コロナウイルス対応特別研究プロジェクト「ポストコロナ社会構築研究スタートアップ支援」

新型コロナウィルス対応における移動制限とその効果・影響の分析
Examining impacts of moving restrictions against the novel coronavirus epidemics-

Activity report・Results--●Aim: Assessing the Japanese model of self-restraint

The state of emergency (SOE) declared in April 2020 attempted to control theepidemic by asking people to refrain from going out, thus reducing mobility.
What was the effect of this on preventing the spread of the disease and what was thesocial impact?

➋ Social scientific analysis of individual life behavior change

Online survey confirmed significant reduction in outing behaviour associated with SOE (2A)-

Women, low income, not working, using public transport, and having a chronic illness weremore likely to be discouraged from going out-

Concerns about public perceptions of going out were also associated with reduced going out-

Large decrease in walking and going out in metropolitan areas and younger age groups wereobserved according to iphone healthcare app records (2B)

-Decline in physical activity, increase in sedentary time and decline in mental health were also
associated with regional characteristics➊ Statistical analysis of human movement and infection spread
Association between epidemic trends and human mobility: the visualisation ofspatio-temporal trends of epidemics clearly indicated this (1A).

-Using Mobile Spatial Statistics, common patterns of changes in the ambient
population in each city were extracted resulting in classification of cities (1B).

-Changes in the ambient population of "nightlife" type grids (1C) were most strongly
associated with the changes in reproduction rates of COVID-19 (1D).

2A: SOE and changes in outing behaviors-

1B: Temporal changes ofmobility patterns in three cities.

-2B: SOE and step count changes➌ Informatics study of the effect on preventing the spread of infection
Theoretical epidemiological investigation of whether uncoerced infection control can be aneffective epidemic control strategy (mathematical analysis and simulation of a single
intervention as a simple case) (3A)

It is suggested that there is an appropriate timing and intensity of intervention that can reduce
the number of infected people to the lowest level, and that interventions that are too strong
not only have a significant impact on people's social lives, but are also not the best in terms of
preventing the spread of infection (3B)

1A: Space-time density of COVID-19
1C: Estimated nightlife type grids
3A: Simulation of the effects of interventions withdifferent timing●-

1D Temporal changes in the ambient population in nightlife typegrids and reproduction numbers of COVID-19-Conclusion

3B: Intervention intensity andepidemic reductions

The " Japan model " of non-coercive curtailment of going out was effective in controlling
infection through mobility suppression during the emergency declaration in April 2020.
On the other hand, there were people who had difficulty in curtailing their mobility and people
who were greatly affected by curtailing their mobility, depending on area characteristics.