Variability in Human Mobility during the Third Wave of COVID-19 in Japan

Round 1

Reviewer 1 Report

Dear Authors,

The manuscript “Variability in human mobility during the third wave of COVID-19 in Japan” it is on average original, as there are equivalent works in the literature in other parts of the world.

In my opinion, however, there are some comments related to the presentation that need to be improved in order to be published.

Some suggestions to the authors to improve the text:

Abstract: An abstract summarizes the main aspects of the entire article in a prescribed sequence that allows readers to quickly get the gist or essence of the article or article in order to decide whether to read the entire paper article. It also prepares readers to follow detailed information on the methods used, including analyzes and arguments in your full article. Finally, the abstract helps readers remember the key points of the article. At least the general purpose of the study and the research problems examined should be outlined. . It is very challenging to know the significance of this research in this abstract. Rewriting the abstract to address the issues raised will help improve the quality of the article and I would suggest that the authors may consider doing so.

Introduction: The introduction could be improved at, furthermore the meaning of the research must be clearly stated.

Results and discussion: the subdivision into many subpargraphs makes it difficult to read the text, therefore it is suggested where possible to combine the subparagraphs.

Conclusions: the authors should rewrite the conclusions, expanding them and highlighting the results obtained in this study.

 

Author Response

Dear reviewer,

Thank you for your review and kind suggestions to improve the manuscript.

The responses to your comments are shared below. In addition, the revised wording and sentences are indicated in red and underlined.

 

Comment1: Abstract: An abstract summarizes the main aspects of the entire article in a prescribed sequence that allows readers to quickly get the gist or essence of the article or article in order to decide whether to read the entire paper article. It also prepares readers to follow detailed information on the methods used, including analyzes and arguments in your full article. Finally, the abstract helps readers remember the key points of the article. At least the general purpose of the study and the research problems examined should be outlined. . It is very challenging to know the significance of this research in this abstract. Rewriting the abstract to address the issues raised will help improve the quality of the article and I would suggest that the authors may consider doing so.

Response: Thank you for your valuable suggestion and insights. Accordingly, we have now revised the abstract per your suggestion, as follows:

“Understanding factors regarding individual variability in human mobility during the COVID-19 pandemic would help inform future political and medical decisions. Particularly, understanding environmental factors would provide effective evidence for future urban development and the construction of a mobility service. Given the limited related evidence thus far, we investigated inter-individual variability in human mobility regarding life space during COVID-19 in Japan. We conducted an online survey to assess human mobility, demographics, and personality, and city structure surveys for objective environmental factors. Human mobility was assessed using the Life Space Assessment (LSA) questionnaire. Result revealed that the total LSA score was significantly higher in people who were men, middle-aged, working, living with their children, public transportation users, bicycle users, and car drivers, and those having a higher score for extraversion and ego resiliency and a lower score for conscientiousness. People living in the city with high traffic on the roads between plains and mountains had a higher LSA score, and had a lower score where there were many plains with a consistent road density, revealing diverse individual and environmental factors associated with human mobility during the pandemic. Thus, political decisions for urban development should consider these characteristics, the pandemic, and individual convenience.”

Comment2: Introduction: The introduction could be improved at, furthermore the meaning of the research must be clearly stated.

Response:

Thank you for your suggestion. We have presently revised the introduction and added several sentences for elaboration, as per your suggestion. The inclusions are as follows:

“A stretch of life space and sustainable transportation may contribute to the development of socio-economic activities, thus improving individuals’ quality of life (QoL). However, after the outbreak of the coronavirus disease 2019 (COVID-19), socio-economic activities involving outings were restricted based on political and medical decisions to reduce infection spread in Japan and other countries. Such restrictions on outings and human mobility can consequently vary a person’s QoL and subjective happiness. Indeed, the lockdown imposed due to COVID-19 has resulted in negative consequences for individuals’ mental health and happiness [1-5].

Reduced human mobility would have a large inter-individual variability depending on individual environments, such as the residential area, occupation, family structure, etc., as well as personality, in line with results of studies before the COVID-19 pandemic, suggesting that human mobility was affected by these factors [6]. The variability might also lead to a difference in the risk of infection and other diseases, including mental illness and disabilities due to reduced life space and physical activity. Thus, understanding factors regarding individual variability in human mobility during the COVID-19 pandemic would help inform future political and medical decisions; specifically, to seek and control high-risk populations vulnerable to infection and other diseases and support those requiring help. Further, understanding both the types of environmental factors that unnecessarily increase human mobility and those that reduce human mobility and compensate for negative individual characteristics, would provide effective evidence for future urban development and the construction of a mobility service.  However, evidence pertaining to these factors has been limited, at least in Japan.

Hanibuchi et al. (2021) [7] reported that specific individual and social characteristics such as younger people, women, unemployed individuals, those using public transportation, those with chronic diseases, individuals living in metropolitan areas, and those living with more than two people were associated with spending less time outside their homes. However, the sample size at different time points for each analysis was not abundant, and there was a lack of information in terms of the impact on a range of environments in which the individuals move within, and not only on the time spent outside their homes and/or the frequency of outings. Furthermore, the previous study has been limited in investigation of the neighborhood city structure.

Therefore, this study aimed to investigate the factors of inter-individual variability in human mobility in each range of life space environments during the COVID-19 pandemic in Japan. In addition, we conducted a cross-sectional analysis of the association between human mobility and subjective happiness.”

 

Comment3: Results and discussion: the subdivision into many subpargraphs makes it difficult to read the text, therefore it is suggested where possible to combine the subparagraphs.

Response:

We apologize for the several subparagraphs, which may have impeded readability. Since we explored several topics, we felt that they would benefit from having separate subheadings. As per your comment however, we have ensured that the subheadings of the results and the discussion are consistent.

 

Comment4: Conclusions: the authors should rewrite the conclusions, expanding them and highlighting the results obtained in this study.

Response:

Thank you for your suggestion. We would have revised the conclusion per your suggestion as follows:  

“This study identified several factors that are determinants of human mobility during the COVID-19 pandemic in Japan. With regard to individual factors, including personality, our study revealed that gender, occupation, child status, vehicle use types, and specific personality types would be strong determinants of inter-individual differences. In particular, multi-aspect support is needed for people living with children during the pandemic. With respect to environmental factors, our study revealed that there is a lack of daily living services, including medical, welfare, and commercial facilities, and core public transportation routes, which increases human mobility in areas far from home. Thus, it is important to complement systems and/or services, such as home delivery services, to reduce the extent of human mobility in rural and suburban areas during the pandemic, in addition to urban reconstruction. However, even when these systems are developed, workers responsible for logistics and delivery are constantly needed in real time. It will also be necessary to investigate the construction of a system and urban design that will enable the minimum amount of human mobility and optimal logistics. Together, we suggest the necessity of making political decisions based on the characteristics of each area and individual, while also considering resilience measures against the pandemic and individual convenience for urban development.”

Further, we have added some additional text to the discussion to help readers better understand the results and the significance of this study (lines 429-437).

Author Response File: Author Response.docx

Reviewer 2 Report

Based on a large-scale, government-supported study, this paper reports various valuable primary results on human mobility in the COVID-19 pandemic in Japan. Following improvements and amendments in the manuscript can be considered.

1. Page1: Since all authors have the same affiliation, there is no need to superscript “1” after their names.
2. Page1: Please consider including Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) in the keywords.
3. Page7: In section 3.2, I don’t understand what the “Figure 2A, Figure 2B, and Figure 2C are pointing to. The “Urban types (number of area)” have the same symbols duplicated in A, B, C…, which can be confusing.
4. Page13: In Figure 3, please check if the symbols “A, B, C…” are correctly given.
5. Page16: In Figure 5B, each factor seems to correspond to sections 4.1, 4.2, 4.3, 4.4, 4.5, and 4.6; however, there are no COVID-19 and General happiness shown.
6. Page17: In section 4.3, the manuscript “This is the first study to describe the associations between ego resiliency and human mobility…”. It would be worthwhile to check the possibility of a confounding factor, for example, age, between the two.
7. Page18: The authors mention the lack of daily living services and the need for home delivery services, however, which are also maintained by human service providers. The results show that the LSA is high for workers and people living with children because they cannot refrain from the outing, unlike students. The authors should refer to what mobility distribution is desirable as a whole society contributing to political decisions.

Author Response

Dear reviewer,

Thank you for your review and kind suggestions to improve the manuscript.

The responses to your comments are shared below. Further, the revised wording and sentences are indicated in red color.

 

Comment 1: Page1: Since all authors have the same affiliation, there is no need to superscript “1” after their names.

Response: Thank you for your comment. We have accordingly revised the same.

 

Comment 2: Page1: Please consider including Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) in the keywords.

Response: Thank you for your valuable comment. We have presently added this keyword to the list.

 

Comment 3: Page7: In section 3.2, I don’t understand what the “Figure 2A, Figure 2B, and Figure 2C are pointing to. The “Urban types (number of area)” have the same symbols duplicated in A, B, C…, which can be confusing.

Response: We apologize for any confusion caused by the incomplete content that was previously shared. We made a mistake in pasting the figure. The figure attached in Figure 2 was actually Figure 3. We have now added the correct Figure 2.　The other figures have been corrected accordingly. In addition, the text for figure 4 was not appropriate, and has been corrected as “The state of emergency was associated with higher LSAtotal scores (β = 0.7108, P = 0.0198, Figure 4A) and LSA at level 5 (β = 0.2753, P < 0.0001, Figure 4E), whereas the state of emergency was associated with a lower LSA score at levels 2 (β = -0.0354, P = 0.0123, Figure 4B), 3 (β = -0.0918, P < 0.0001, Figure 4C), and 4 (β = -0.0799, P = 0.0054, Figure 4D).”

 

Comment 4: Page13: In Figure 3, please check if the symbols “A, B, C…” are correctly given.

Response: We apologize for placing the figure inappropriately, and have corrected the same (as explained in our answer to Comment 3).

 

Comment 5: Page16: In Figure 5B, each factor seems to correspond to sections 4.1, 4.2, 4.3, 4.4, 4.5, and 4.6; however, there are no COVID-19 and General happiness shown.

Response:  As you have mentioned, we did not indicate the relationship between human mobility and subjective happiness in the figure, because the meaning of the figure is different and there is no significant relationship. On the other hand, as you pointed out, we realized that the effect of Covid-19 on human mobility was not shown in the figure. Therefore, we revised the figure. Thank you very much for your excellent suggestion. In addition, we made sure that the subheadings of the results and the discussion are consistent, also aligning with reviewer 1's comment.

 

 

Comment 6: Page17: In section 4.3, the manuscript “This is the first study to describe the associations between ego resiliency and human mobility…”. It would be worthwhile to check the possibility of a confounding factor, for example, age, between the two.

Response: Thank you for your comment. The statistics for the variables (e.g., age, sex, personality, etc.) in Table 3 were all adjusted for each other in GLM. Therefore, the p-values shown in the relevant part of this study have already been adjusted for age and other factors. In response to your comment, we thought that the description was indeed difficult to understand, so we added the following sentence to the footnote of Table 3. “The statistics of all these variables were considered to be interrelated using the general linear model.”

 

Comment 7: Page18: The authors mention the lack of daily living services and the need for home delivery services, however, which are also maintained by human service providers. The results show that the LSA is high for workers and people living with children because they cannot refrain from the outing, unlike students. The authors should refer to what mobility distribution is desirable as a whole society contributing to political decisions.

Response: Thank you for your very thoughtful suggestions. As you have shared, it was a description that lacked consideration regarding the current state of the social system where someone may have to undergo some sacrifice to support someone else.　According to your comment, we have revised the conclusion as “This study identified several factors that are determinants of human mobility during the COVID-19 pandemic in Japan. With regard to individual factors, including personality, our study revealed that gender, occupation, child status, vehicle use types, and specific personality types would be strong determinants of inter-individual differences. In particular, multi-aspect support is needed for people living with children during the pandemic. With respect to environmental factors, our study revealed that there is a lack of daily living services, including medical, welfare, and commercial facilities, and core public transportation routes, which increases human mobility in areas far from home. Thus, it is important to complement systems and/or services, such as home delivery services, to reduce the extent of human mobility in rural and suburban areas during the pandemic, in addition to urban reconstruction. However, even when these systems are developed, workers responsible for logistics and delivery are constantly needed in real time. It will also be necessary to investigate the construction of a system and urban design that will enable the minimum amount of human mobility and optimal logistics. Together, we suggest the necessity of making political decisions based on the characteristics of each area and individual, while also considering resilience measures against the pandemic and individual convenience for urban development.”

 

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The authors have addressed all my comments. I believe the manuscript is ready for publication. Thanks for responding to my comment.