Mental Health and Parent–Child Residential Distance for Older People: Cross-Sectional Study Using a Comprehensive Survey of Living Conditions in Japan

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript provides an analysis of data from an anonymized survey in Japan with regard to the distance of older adults from their children and their levels of mental health. The study attempts to provide recommendations for urban sustainability based on these findings. The results indicated that compared to younger older adults (65-74) older older adults (75 and above) who lived closer to their children had poorer mental health. It was suggested from these findings that promotion of older adults in housing in the same city, but not in the same neighborhood or household or a different city, would be best for their quality of life. It was also suggested that professional care support be available. Some limitations of the study and the need for more research are elaborated. 

 

The strengths of the manuscript include the use of national primary statistical data in the form of a survey that was conducted by civil servant investigators among a large sample of the Japanese population utilizing stratified random sampling. The final sample size, after categories of exclusion, was 2,437 older adult (65 and above) respondents. The survey included a scale for psychological distress as a screen for mental illness (translated into Japanese from an American-developed scale).

 

Some issues about the manuscript: that might be addressed, 

(1)  While the size of the sample is a strength, the loss of nearly half of the older adults due to the older adults not having any children or “other reasons” is not mentioned as a limitation, and no separate frequencies for these two exclusion criteria are provided (2,358 were excluded from among a total of 4.795 older adults). This size of a loss of respondents represents a potential impact on the results. What was the mental illness findings for these excluded cases, for instance? For example, are those without children worse off than any or some of those with children? What “other reasons” existed and how many potential respondents were excluded from the data?

(2)  The measure (along with distance between older adult parents and their children and mental health) was “confidants talking to about stress.” This latter variable is never explained adequately or clearly. How exactly was this information asked? Did the item include a list of possible confidants to be checked (as in Table 3)? Was the question open-ended, with the older adult providing those in whom they confided about their stress? Was a response about an entire set of possible confidants provided and yes or no or a ranking of how often they talked to these various “confidants they talk to their stress” asked? Is that what a “multiple-answer question” refers to? This study could not be replicated without more specific details about this variable/measure. The findings described from Table 3 are logical (older adults don’t talk to their family as much when they live in another city; the greater the distance between their residences the less likely they talk to their family). How would you explain that those who live together do not talk to one another about stress? What does “too close” actually mean as an explanation?

(3)  Was the nationally conducted study performed as an interview method or as a survey on paper?

(4)  A major shortcoming of the study and its interpretation is related to the 65-74 group compared to the 75+ group or changes within the group over time and mental health. For instance, in line 363 it is stated that “mental health worsens among late-old-stage parents living closer to their parents.”  These cross-sectional data do not provide information on changes over time. A longitudinal (measures over time) would be necessary to provide “worsens” or “did not change” (see line 366) findings. Differences in measures can be shown between groups, but not within the same group over time with cross-sectional data.

(5)  The primary problem is identified in the limitations: “lack of causality.” It is not possible with these data to determine what might have caused the residence of the older adults compared to that of their children (distance) or the timing of mental health issues in late life. Did the mental health of the older adult exist before their present living location took place or after their present living location with respect to their child? Is it not possible that the mental health of the older adult improved after moving closer to their child? There seems to be no data on when the current housing location was entered into, how long it has existed, or when their mental health issues took place. This limitation is indicated generally but not specifically in the limitations section (temporal precedence between causes and effects).

(6)  Relatedly, is it not possible that the reason that parents and children are living closer is that the mental (and possible physical as well) health of the older adult (especially the late-old adults) has produced this living distance condition? Did the older adult move, or did the child move in with the older adult at some point, and when? There is no measure of the length of time that this distance condition existed. If a move took place, did the parent and/or child move together relatively recently or has it been longer?

(7)  The study conclusions seem to imply that living with one’s child in old age and particularly late old age should be discouraged as should living in the same neighborhood. Are those who live in different cities responsible for their older adult parent’s mental health issues (should they move to the same city?)? Living in the same city as an older adult parent does seem logically to be of benefit to the older adult and their well-being, but as noted, each case is different as would be the true in different cultures as well. It also seems advised that better and more availability of professional caregiver support is beneficial in all cases.

(8)  While it is stated (line 207) that there were no general gender differences for parent-child residential distance, what about gender by age differences (interaction)? What about gender and mental health? Interaction of gender and distance for mental health? (like in Table 2 for age group)

 

 

There are additional minor manuscript issues: (a) In the introduction it is noted that “the aging population has become a serious social problem.”  That term “problem” is repeated later in the same paragraph. This wording seems to identify older adults as a “problem.” It is certainly a challenge to cultures and societies and an issue that needs to be addressed, but more people living long lives is not a problem, but rather a change in the population demographics that require attention and change in many aspects and resources of a society. The policy-making promotion that is noted in the Discussion does not imply a problem so much as a need to address the population as it changes. (b) On page 2 there are two paragraphs that being with “This study…”. It would seem that these refer to studies other than the present study, perhaps in both cases. If so, the study being discussed is not clear. Information about the current study is most often placed after the Introduction or at its very end. (c) On page 3 line 115, is “supposed” actually “supported”? In line 128 “confidents” should be “confidants”? (d) There are multiple repetitions of the same information (e.g., about the 2016 Comprehensive Survey of Living Conditions) in the early sections of the paper.

Comments on the Quality of English Language

Generally good. There were some minor issues as noted in the last section of the review comments to the authors.

Author Response

Dear Reviewer:

 

We appreciate the reviewer for the generous comment on the manuscript. We have attached our response letter in PDF format. We believe that the manuscript is now suitable for publication in Sustainability and look forward to hearing from you concerning your decision.

 

Yours sincerely

 

 

Riko Kawashita, Haruka Kato

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

To the authors:

In general (in my opinion) the work is good. The subject matter is interesting, and its study has important implications for the future design of social and health care measures in increasingly ageing societies (Japan, as the authors document, is no exception). The introduction,  the methodology used, and the analysis of the results sound good and are in line with what is expected in this type of work.

I will make some "minor" considerations that I hope could be helpful in improving the manuscript.

 

·         In the introduction, given its relevance, I suggest going a little deeper into the importance of environmental housing in the mental health of older people, in the certainty that the potential reader will appreciate it.

·         I recommend justifying (also in the introduction) a little more the interest of the parent-child residential distance variable and its basis and anchoring in the previous literature. Also, delve a little deeper into the potential gains of studying the link between mental health and parent-child residential distance.

·         I suggest including in the Data section information about the participants (sample size) and some of their more general characteristics (gender, for example) (it does not seem reasonable that the reader should have to wait for the results to know these aspects). In this same section, the authors point out that they have used Japanese version of the K6 scale, more detailed information would be appreciated. Also, more information on who the confidants are is needed. Finally, this section raises, in my opinion, many questions that need to be answered here (not in the results section). 

·         The section of participants fits poorly in the results, I suggest including it first.

·         Some issues to clarify and/or expand on in the discussion:

o   Explain in more detail what it is meant by "to have serious mental illness" in line 295.

o   Clarify in the manuscript what are the "other illnesses" referred to in line 296.

o   Indicate what tentative hypothesis the authors would formulate from the result that "the parent-child residential distance is more appropriate for HLSC group than HLSN group from the perspective of mental health" (lines 300-302); in short, any consideration or explanatory attempt (even if at a tentative level).

o   The result "the average mental score of the late-old-stage HLT (parent-child household living together) group exceeded the cutoff value that indicates serious mental illness", requires, in my view, also a deeper discussion.

o   A further elaboration of the practical implications of the study by indicating any further concrete guidelines for action (at preventive or intervention level) would be welcome.

In short, these are recommendations that justify the work of revision, but I would like to emphasize, once again, that they are minor aspects that do not invalidate the seriousness and rigour of this work.

Author Response

Dear Reviewer:

 

We appreciate the reviewer for the generous comment on the manuscript. We have attached our response letter in PDF format. We believe that the manuscript is now suitable for publication in Sustainability and look forward to hearing from you concerning your decision.

 

Yours sincerely

 

 

Riko Kawashita, Haruka Kato

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Strengths:

1. Relevance: The topic of the study is highly relevant to current societal issues, focusing on aging populations and urban sustainability.
2. Clear Objective: The study has a well-defined objective – to examine the relationship between mental health and parent‒child residential distance for older parents.
3. Methodology: The use of a cross-sectional study design and the employment of two-way ANOVA for analysis indicate a methodical approach to the research question.
4. Data Source: The utilization of data from the 2016 Comprehensive Survey of Living Conditions adds credibility, as it presumably represents a large and relevant sample.
5. Significant Findings: The discovery of a statistically significant difference in mental health based on parent‒child residential distance and age group is noteworthy and contributes new insights to the field.

Weaknesses:

1. Abstract Clarity: The abstract is somewhat unclear and disjointed. For instance, the acronyms HLT and HLSC are not defined in the abstract, which might confuse readers.
2. Study Design Limitations: As a cross-sectional study, it can identify correlations but not causation. This limitation should be acknowledged.
3. Generalizability: The study is focused on Japanese housing policies and may not be generalizable to other cultural or geographical contexts.
4. Potential Bias in Data Source: The reliance on a single data source (the 2016 Comprehensive Survey of Living Conditions) might introduce bias or limit the scope of the findings.
5. Conclusion Overreach: The abstract suggests policy implications, yet it's unclear if the study sufficiently explores the complexities that would support such policy recommendations.

 

Comments on the Quality of English Language

Extensive editing of English language required

Author Response

Dear Reviewer:

 

We appreciate the reviewer for the generous comment on the manuscript. We have attached our response letter in PDF format. We believe that the manuscript is now suitable for publication in Sustainability and look forward to hearing from you concerning your decision.

 

Yours sincerely

 

 

Riko Kawashita, Haruka Kato

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Reviewer comments were addressed in revisions.

Noticed that Figure 1 was inserted twice in the manuscript. Associated with these insertions, the header for Section 2.2 was misplaced.

Author Response

Dear Reviewer:

 

We appreciate the reviewer for the generous comment on the manuscript. We have attached our response letter in PDF format. We believe that the manuscript is now suitable for publication in Sustainability and look forward to hearing from you concerning your decision.

 

Yours sincerely

 

 

Riko Kawashita, Haruka Kato

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Agree, accepted.

Author Response

Dear Reviewer:

 

We appreciate the reviewer for the generous comment on the manuscript. We have attached our response letter in PDF format. We believe that the manuscript is now suitable for publication in Sustainability and look forward to hearing from you concerning your decision.

 

Yours sincerely

 

 

Riko Kawashita, Haruka Kato

Author Response File: Author Response.pdf