Sleep Habits in Pairs of Japanese High School Students and Their Mothers in Summer and Autumn
Round 1
Reviewer 1 Report (Previous Reviewer 2)
I reviewed the revised manuscript and the response to minor reviewers' comments. Revised Manuscript is well written. The authors have responded appropriately. This is an interesting paper with increased scientific soundness after their corrections. There are limitations to the study but they are stated. Worth considering
Author Response
Response to Reviewer 1 comments
The comments from reviewer 1:
I reviewed the revised manuscript and the response to minor reviewers' comments. Revised Manuscript is well written. The authors have responded appropriately. This is an interesting paper with increased scientific soundness after their corrections. There are limitations to the study but they are stated. Worth considering　
Response: Thank you for your comments. Based on the comments and advice given by reviewers #2 and # 3, we have included additional limitations and discussions. Please confirm the revised points in the manuscript.
Reviewer 2 Report (New Reviewer)
This research showed the high school students’ and their mothers’ seasonal change of objective and subjective sleep-wake pattern as well as their bedroom condition. The data of this study is thought to be reliable and its descriptive analyses provide significance information to readers. However, I want to request the authors to add some information on this manuscript.
The results of this study showed interesting seasonal change of relationship between the sleep-wake pattern of high school students and that of their mothers. However, the discussion for this point is weak. I suggest to authors to discuss more about this point, why the relationship between mothers’ and students’ sleep-wake pattern was different in summer and in autumn.
Please consider to show the correlation coefficient between the bedroom conditions of students and those of mothers in each season. The results of this analysis may help to discuss the above-mentioned seasonal change of relationships between sleep-wake pattern of the students and that of their mothers.
In addition, please clearly show how many students were participate of this survey in summer break in Methods section. As authors mentioned in discussion, as well as their seasonal bedroom conditions, the change of social factor (school attendance) may affect students’ and their mothers’ sleep.
Author Response
Response to Reviewer 2 Comments
The comments from reviewer 2:
Point 1: This research showed the high school students’ and their mothers’ seasonal change of objective and subjective sleep-wake pattern as well as their bedroom condition. The data of this study is thought to be reliable and its descriptive analyses provide significance information to readers. However, I want to request the authors to add some information on this manuscript.
The results of this study showed interesting seasonal change of relationship between the sleep-wake pattern of high school students and that of their mothers. However, the discussion for this point is weak. I suggest to authors to discuss more about this point, why the relationship between mothers’ and students’ sleep-wake pattern was different in summer and in autumn.
Please consider to show the correlation coefficient between the bedroom conditions of students and those of mothers in each season. The results of this analysis may help to discuss the above-mentioned seasonal change of relationships between sleep-wake pattern of the students and that of their mothers.
Response: Thank you for your comment. We examined the relationship between the bedroom thermal conditions of the mothers and students. As you have suggested, interesting findings were detected revealing that bedroom temperature was correlated between mothers and students and that the hot and humid bedroom conditions in summer might be a factor that induces a correlation or concordance in nocturnal sleep between mothers and children. Please confirm the descriptions in the discussion (lines# 302–309)
Point 2: In addition, please clearly show how many students were participate of this survey in summer break in Methods section. As authors mentioned in discussion, as well as their seasonal bedroom conditions, the change of social factor (school attendance) may affect students’ and their mothers’ sleep.
Response: Thank you for your comments to clarify the school term conditions in the data collection in summer. We described the fact in the end of the section “4.1. Participants and procedure”.
Reviewer 3 Report (New Reviewer)
Dear authors, follow some coments to clarify my reading and some with the intent to improve the textwork
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2 weeks actigraph records allow better two weekend records that are more informative than one weekend sampling.
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SJL is calculated not from time in bed as you did, but from total sleep period.
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Time in bed is a tricky concept in actigraphy studies, because one can be in bed but with no intention of sleep, as may be the case in your sample when the students leave lights on.
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legend table 1, add standard deviation instead of only deviation
- Line 363 “ The other point to be educated for the high school students should be to prevent napping after returning home” I do not agree with this recomendation, short naps after lunch use to be healthy and are cultural habits in many countries. In the study of Santos (refs 32) the authors report association of long naps with later bedtimes and reduced TIB.
Author Response
Response to Reviewer 3 Comments
Point 1: 2 weeks actigraph records allow better two weekend records that are more informative than one weekend sampling.
Response: Thank you for your comments. I have described this point in the last part of the paragraph of the discussion section that explains the limitations of the study (lines#:379–383).
Point 2: SJL is calculated not from time in bed as you did, but from total sleep period.
Response: Thank you very much for your comment. We have recalculated SJL from the total sleep period, which was from sleep onset to the last sleep episode in TIB. As a result, although the values were not very different from those calculated from TIB, a significant negative correlation in autumn, reported in the previous manuscript, became insignificant. Related revisions have been made in the results, discussion, and methods sections.
Point 3: Time in bed is a tricky concept in actigraphy studies, because one can be in bed but with no intention of sleep, as may be the case in your sample when the students leave lights on.
Response: We appreciate your valuable comment. To address this issue, we made additional discussions by referring to a review paper (ref #33) to introduce the validity of actigraphy compared with polysomnography (lines #370–379). Also, in Section 4.2.1., we made minor revisions to the definition of TIB from “TIB (defined as the primary sleep period during which participants were trying to sleep in bed)” to “TIB (defined as the primary sleep period during which participants were trying or falling into sleep).”
Point 4: legend table 1, add standard deviation instead of only deviation
Response: Thank you very much. We revised this text.
Point 5: Line 363 “ The other point to be educated for the high school students should be to prevent napping after returning home” I do not agree with this recomendation, short naps after lunch use to be healthy and are cultural habits in many countries. In the study of Santos (refs 32) the authors report association of long naps with later bedtimes and reduced TIB.
Response: Thank you for your comments. As you pointed out, short naps in the early afternoon are beneficial in preventing sleepiness in the afternoon. We meant that this recommendation was to prevent napping in the late afternoon or evening. This behavior is closely associated with a late bedtime and daytime sleep impairments, such as excessive sleepiness. To clarify this point, we have revised this section (lines #398–403).
Thank you very much.
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
Dear sir
It's a very interesting study. It is a study of the correlation between mothers and adolescence's sleep and circadian rhythm depending on seasons.
To generalize, the number of pairs of mothers/high school students who participated in the study is small. I think it is a common situation, if not through scientific research like this study, that mothers with middle and high school children wake up earlier than children and have to do housework.
In addition, this group participating in this study cannot represent middle and high school students in Japan because it concludes that sleep education is necessary due to the short sleep time of middle and high school students.
In initial suggestions, authors have focused on seasonal differences in the design of this study, the conclusion is general sleep for adolescents.
1) Although shown for statistical significance through p<0.0001/<0.05, adding the p-Value of the statistics for each statistic in each tables, helps you understand this table.
2) In the text description, there is no difference between season and group, but in Figure 1, was the difference in season 3 and 4, the causes of sleep loss of mother participants, statistically meaningful?>> It is necessary to add a description for this.
3)Although the number of subjects is small, the cause of sleep loss in male and female adolescents is different. Have you analyzed the gender differences?
In summary,
Since the authors mentioned the issue of the season at the beginning of this study, I hope the conclusion will also summarize the main points of the season. Add statistics p-value to each table, and too many tables make it difficult to communicate what this paper saying.
I would like to organize the tables by categories. Gender is an important factor in adolescent sleep, so I recommend you to check if there is any gender difference.
Reviewer 2 Report
- In the abstract, the investigators should provide more data on statistical significance and objective data comparison in the results section of abstract
- P-Values should also be added in the Figure 1
- Questionnaire should be provided in Supplementary
- Has Questionnaire been validated without bias?
- How was Questionnaire provided? by mail, phone interview? who was the one who conducted the interview?
