A Two-Week Vacation in the Tropics and Psychological Well-Being—An Observational Follow-Up Study
Round 1
Reviewer 1 Report
This paper makes a significant contribution to the literature. I have made a few minor comments below that I think would help increase accessibility. Over complex abstracts with information you cannot fully comprehend until you have read the paper can be extremely off putting to potential readers.
The main issue from my perspective was the lack of clarity around the relationship between the trial and your study, I felt I had to do quite a lot of work to feel clear on this. I may not have persevered if I was not reviewing it. I think this needs to be spelled out clearly in the introduction with a naïve reader in mind.
The role of the vaccination programme is a bit confusing until half way through the paper. It would be really helpful to explain this really clearly towards the end of the introduction. The abstract could then be less technical and more accessible, currently, what is an interesting study is a bit lost in unnecessary references to waves and wave sum scores. I appreciate this is necessary in the body of the paper but you could make the abstract more accessible and focused on the interesting elements by reframing. For example:
We assessed the travelers’ psychological distress with a general health questionnaire (GHQ-12) and retrieved data on TD from the trial database. The GHQ-12 was completed filled in before (wave 0), at return (wave 1) and one-month after (wave 2) the trip. Of the 174 participants, 73% were women, with a mean age 40 years. Twenty-four percent reported psychological distress before travelling, 10 % immediately after and 16% one-month after the trip (GHQ-12 3 or more; 0-12 scoring). The findings showed that psychological well-being increased after the tropical holiday, the GHQ -12 middle wave sum score differed from the wave 0 (p < 0.001) and wave 2 (p = 0.008) sum scores. with traveller’s reporting highest levels of wellbeing on their return, with evidence of a lasting improvement.
In the method can you add a couple of example questions from the GHQ-12 and remove the weblink from line 73.
Line 50 just wanes not wanes off
Ethical consent repetitive line 66 and line 106 - edit and remove one.
Section 2.3. Line 98 please explain clearly how the field trial fits with your study.
Line 239-40 unclear - needs rephrasing
line 248-50 unclear - needs rephrasing
Line 293-299 - do you need this? It felt a bit tangential.
Author Response
Letter for reviewers IJERPH 20220814
The authors are grateful for the time used to assess the ms by the reviewers. Please see detailed comments below.
Reviewer 1
Comments and Suggestions for Authors
This paper makes a significant contribution to the literature. I have made a few minor comments below that I think would help increase accessibility. Over complex abstracts with information you cannot fully comprehend until you have read the paper can be extremely off putting to potential readers.
The main issue from my perspective was the lack of clarity around the relationship between the trial and your study, I felt I had to do quite a lot of work to feel clear on this. I may not have persevered if I was not reviewing it. I think this needs to be spelled out clearly in the introduction with a naïve reader in mind.
We have now clarified the introduction as advised.
The role of the vaccination programme is a bit confusing until half way through the paper. It would be really helpful to explain this really clearly towards the end of the introduction. The abstract could then be less technical and more accessible, currently, what is an interesting study is a bit lost in unnecessary references to waves and wave sum scores. I appreciate this is necessary in the body of the paper but you could make the abstract more accessible and focused on the interesting elements by reframing. For example:
We assessed the travelers’ psychological distress with a general health questionnaire (GHQ-12) and retrieved data on TD from the trial database. The GHQ-12 was completed filled in before (wave 0), at return (wave 1) and one-month after (wave 2) the trip. Of the 174 participants, 73% were women, with a mean age 40 years. Twenty-four percent reported psychological distress before travelling, 10 % immediately after and 16% one-month after the trip (GHQ-12 3 or more; 0-12 scoring). The findings showed that psychological well-being increased after the tropical holiday, the GHQ -12 middle wave sum score differed from the wave 0 (p < 0.001) and wave 2 (p = 0.008) sum scores. with traveller’s reporting highest levels of wellbeing on their return, with evidence of a lasting improvement.
We have now made changes as advised above to the abstract.
In the method can you add a couple of example questions from the GHQ-12 and remove the weblink from line 73.
Weblink removed and examples added.
Line 50 just wanes not wanes off
Corrected as advised.
Ethical consent repetitive line 66 and line 106 - edit and remove one.
Not removed due there being two separate ethical assessments to this psychological well-being trial and OEV trial, now both clarified in the ms text.
Section 2.3. Line 98 please explain clearly how the field trial fits with your study.
In “study design” we have earlier described “As the OEV123 trial was designed to have only a minor impact on the course of the holiday, it provided us with the opportunity to explore the psychological well-being of travelers taking a holiday in the tropics.” and we have now added “ Participants of OEV -vaccination trial were generally healthy adults, who travelled to a tropical holiday.”
Line 239-40 unclear - needs rephrasing
We have now clarified the sentence “The TD incidence rates in this study are in line with the TD rate of 69% that was reported in an earlier prospective study of 460 international travelers [25].”
line 248-50 unclear - needs rephrasing
Now clarified “An earlier 1999 study conducted in Jamaica reported that TD affected quality of life and general well-being negatively, suggesting travelers would benefit from the ETEC vaccine [27].”
Line 293-299 - do you need this? It felt a bit tangential.
We have now shortened the text and deleted the following “Importantly, the duration of the trip was the same for all. Even though the study continued for longer than a year, the temperature at the destination does not vary very much by season”
Reviewer 2 Report
This study measured the psychological well-being of TD (traveler's diarrhea) participants after a two-week vacation in the tropics.
In this study, the authors selected the tropics because sunlight prescription helped with winter depression, and showed that TD did not have a major effect on the psychological distress level after a 2-week vacation.
I think the authors have provided some interesting variables that affect psychological well-being.
However, this study seems to have logical flaws and ambiguous study purpose in the study design.
First, sufficient rationale and explanation for the reason for choosing the tropics are needed.
Second, in this study, tropical and TD were selected as factors influencing psychological well-being, and more rationale and explanation are needed.
Third, since all participants are OEV123 trial, it is necessary to mention this in the title.
Fourth, since there is no general control group different from the specific group(TD), the reliability of the study results is low.
Fifth, the main purpose and differentiation of this study are ambiguous. Is differentiation the subject of the study? Is it vacation period? Is it tropical? Is it a period of distress after tropical vacation? Are these factors affecting psychological well-being?
Author Response
reviewer 2
The authors are grateful for the time used to assess the ms by the reviewers. Please see detailed comments below.
This study measured the psychological well-being of TD (traveler's diarrhea) participants after a two-week vacation in the tropics.
In this study, the authors selected the tropics because sunlight prescription helped with winter depression and showed that TD did not have a major effect on the psychological distress level after a 2-week vacation.
I think the authors have provided some interesting variables that affect psychological well-being.
However, this study seems to have logical flaws and ambiguous study purpose in the study design.
We have now tried to clarify the study design and aim further, also based on the other peer review. We have described in the study design “The present study was designed to explore psychological well-being among travelers to the tropics. Volunteers were recruited among the participants of a clinical field trial OEV123 for ETVAX®, an oral diarrheal vaccine against Enterotoxigenic Escherichia coli (ETEC). All participants of the OEV123 trial went on a 12-day trip to Benin, West-Africa. As the OEV123 trial was designed to have only a minor impact on the course of the holiday, it provided us with an opportunity to explore the psychological well-being of travelers taking a holiday in the tropics “. We have now added to the Materials and methods Study design a sentence “ Participants of OEV -vaccination trial were generally healthy adults, who travelled to a tropical holiday.”
First, sufficient rationale and explanation for the reason for choosing the tropics are needed.
We have described in study design “The present study was designed to explore psychological well-being among travelers to the tropics.” Tropics was chosen because we were interested in whether it is psychologically beneficial for a traveler from a Nordic country to visit tropics especially during a long and cold Nordic winter. In the Introduction, we reviewed studies on the role of light in psychological well-being. In the revised version, we further clarified this link by noting that the participants “all travelled to tropics from a Nordic country, wherein winters offer little light in general, and in some days, sun does not even rise at all at the northern regions.”
Second, in this study, tropical and TD were selected as factors influencing psychological well-being, and more rationale and explanation are needed.
As requested, we have further clarified our rationale followingly, immediately in beginning of the Introduction: “The annual number of travelers to the tropics exceeds 300 million according to the World Tourism Organization (UNWTO; https://www.unwto.org/statistic/basic-tourism-statistics). The majority of international arrivals in emerging market economies are for holidays. The number of arrivals has been increasing every year until the current SARS-CoV-2 pandemic: in 2019 it reached 685 million. Holidays´ positive effect on mental well-being is an intuitive explanation for why people travel to tropics so much despite the behaviour´s obvious financial and environmental costs, and frequent costs in terms of physical health, such as contracting travelers` diarrhoea (TD). Scientific evidence base on that hypothesis remains limited, however. Despite these vast numbers of leisure-time travelers, research data on the impact of these journeys to the tropics on the psychological distress or well-being of the travelers are surprisingly scant [1-4].”
Third, since all participants are OEV123 trial, it is necessary to mention this in the title.
We did not consider the trial number relevant at the title-level because the trial was originally designed for testing the vaccine´s effect on TD incidence. However, we have described “As the OEV123 trial was designed to have only a minor impact on the course of the holiday, it provided us with the opportunity to explore the psychological well-being of travelers taking a holiday in the tropics.”, and based on the other review “ Participants of OEV -vaccination trial were generally healthy adults, who travelled to a tropical holiday.”, and still further in the Discussion “Although the present study was conducted among volunteers participating concomitantly in an RCT -study, we believe that the RCT study did not have a major impact on our results. This is because the RCT study had been planned so as to make the travel resemble a regular holiday as closely as possible.” We consider participants representative of travelers to tropics and thus would prefer to keep the original title.
Fourth, since there is no general control group different from the specific group(TD), the reliability of the study results is low.
We have described in the original title that this is an observational follow-up study by study design. We have now added to the study limitations “This is an observational longitudinal study by design.” However, please notice that, in this longitudinal design, the participants are their own controls in well-being, and they traveled at distinct times rather than at a single time point. Thus, the design represents controls in terms of individual situation and the global time/situation, in fact representing rather strong quasi-experimental statistical evidence.
Fifth, the main purpose and differentiation of this study are ambiguous. Is differentiation the subject of the study? Is it vacation period? Is it tropical? Is it a period of distress after tropical vacation? Are these factors affecting psychological well-being?
Please, see our response to the above comment on the study rationale. In the manuscript Introduction, we have further described that “The aim of this study was to assess the impact of tropical holidays on psychological well-being”. Overall, we used a validated instrument to assess psychological distress before, immediately after and one-month after the tropical vacation trip, which associates with likely effect of Holiday on the time course of individual´s wellbeing. We have also now clarified the abstract.
Round 2
Reviewer 2 Report
I agree to publish a modified version of the manuscript.
and think the future studies that supplements the limitations of this study
are needed.
