Evaluation of Workloads of Package Deliverers Focusing on Their Pickup and Delivery Tasks in Republic of Korea

Round 1

Reviewer 1 Report

1. In the introduction section, there is a lack of a justification for the raised research problems in the paper.
2. The Article needs to do a literature review to find a research gap to justify the novelty of the research and develop a conceptual model to be tested using empirical research. This model will enrich the research analytics.
3. The discussion section needs to elaborate and compare the research results to the reference that examined a similar research topic.
4. The end of the paper needs to elaborate on the research implication to theoretical development and managerial practice.
5. The Article needs a summary section.
6. The Article has not offered the limitations or weaknesses of the research. There is an opportunity to be a bit more self-critical.

Author Response

In the introduction section, there is a lack of a justification for the raised research problems in the paper.

Response: Two paragraphs were rewritten to show the justification of the study.

The article needs to do a literature review to find a research gap to justify the novelty of the research and develop a conceptual model to be tested using empirical research. This model will enrich the research analytics.

Response: Six more references were added, and three ANOVA models were included.

The discussion section needs to elaborate and compare the research results to the reference that examined a similar research topic.

Response: More references were added and compared with the findings of the study.

The end of the paper needs to elaborate on the research implication to theoretical development and managerial practice.

Response: The conclusions section (5. Conclusions) was added with the study highlight and significant findings different from other studies.

The Article needs a summary section.

The Article has not offered the limitations or weaknesses of the research. There is an opportunity to be a bit more self-critical.

Response: The conclusions section (5. Conclusions) was added with the study limitations.

Reviewer 2 Report

The manuscript titled “Workload evaluation of package deliverers focusing on pickup and delivery tasks in South Korea” deals with an important issue of occupational medicine.

It is my pleasure to give my insights and highlight some recommendations and commentaries to the manuscript, considering my expertise in the field. I really appreciate this opportunity to discuss the evidence and I hope my contributions could serve to improve the final version of the study.

This is an interesting paper for this field of research. It is well conducted and suitable with the remit and purpose of the journal standard.

Below some advice to improve the manuscript contents:

Please add a clear sentence to highlight better the sustainability of this paper  in all manuscript sections (abstract, introduction, conclusion), according to the remit and purpose of the journal. 

Please add in the first sentence of the introduction section a sentence to highlight better the correlation between covid and Musculoskeletal Pain such as back pain. Please see below:

One Year of COVID-19 Pandemic in Italy: Effect of Sedentary Behavior on Physical Activity Levels and Musculoskeletal Pain among University Students. Int J Environ Res Public Health. 2021 Aug 17;18(16):8680. doi: 10.3390/ijerph18168680. PMID: 34444427; PMCID: PMC8392636.

Please add the limitation of this study, for example the limited number of participants and so on.

Please add the conclusion section to highlight better the scientific/clinical relevance of your work. Please provide a clear “take-home message” of the importance of this paper in the scientific community and the novelty of this paper according to the current literature, to help better readers understanding explaining how this paper is different from other already published.

 

 

Author Response

The manuscript titled “Workload evaluation of package deliverers focusing on pickup and delivery tasks in South Korea” deals with an important issue of occupational medicine.

It is my pleasure to give my insights and highlight some recommendations and commentaries to the manuscript, considering my expertise in the field. I really appreciate this opportunity to discuss the evidence and I hope my contributions could serve to improve the final version of the study.

This is an interesting paper for this field of research. It is well conducted and suitable with the remit and purpose of the journal standard.

Response: Thank you for your kindness.

 

Below some advice to improve the manuscript contents:

Please add a clear sentence to highlight better the sustainability of this paper in all manuscript sections (abstract, introduction, conclusion), according to the remit and purpose of the journal.

Response: Since the authors needed most of time to revise the manuscript until the due date of resubmission (only 10 days), it could not be proofread this time. It will be proofread after minor revision (hopefully) for clear sentences.

Please add in the first sentence of the introduction section a sentence to highlight better the correlation between covid and Musculoskeletal Pain such as back pain. Please see below:

One Year of COVID-19 Pandemic in Italy: Effect of Sedentary Behavior on Physical Activity Levels and Musculoskeletal Pain among University Students. Int J Environ Res Public Health. 2021 Aug 17;18(16):8680. doi: 10.3390/ijerph18168680. PMID: 34444427; PMCID: PMC8392636.

Response: The introductory sentence was added in the abstract.

Please add the limitation of this study, for example the limited number of participants and so on.

Response: The conclusions section (5. Conclusions) was added with the study limitations.

Please add the conclusion section to highlight better the scientific/clinical relevance of your work. Please provide a clear “take-home message” of the importance of this paper in the scientific community and the novelty of this paper according to the current literature, to help better readers understanding explaining how this paper is different from other already published.

Response: The conclusions section (5. Conclusions) was added with the study highlight and significant findings different from other studies.

Reviewer 3 Report

Workload evaluation of package deliverers focusing on pickup

and delivery task in South Korea (1666072)

(Review)

 

Main message of the article

The article by Rim and Jung entitled “Workload evaluation of package deliverers focusing on pickup and delivery task in South Korea” quantified in terms of heart rate reserve, metabolic equivalent of task, standardized Nordic questionnaire, and visual analogue scale the workload of package deliverers (N = 20). The authors found significant effect of task (in particular resting) on the HRR and on MET levels. Cart usage is also found to impact MET. Furthermore, lower back and wrist/hand emerged to be the most affected body parts for the prevalence of musculoskeletal symptoms in the last 12 months and in the last 7 days.

General Judgment Comments

Although the idea behind the study is original, the article lacks some important information to be followed. For instance, original references are not always cited, results are not always reported in the standard format, and figures are not always self-explanatory. For instance, it is not possible to understand the main significant results by looking at the figures, since significance levels are not reported. The investigated variables are interesting and appropriate to explore the workload of package deliverers, but the sample size is too small (N = 20) to obtain any generalizable conclusion from the analysis, due to the low statistical power.

Considering the small sample size, I would recommend the article for Rejection.

 

Major Issues

• The sample size of the study (N = 20) seems too small for any significant conclusion and the sample of participants is almost uniquely represented by males (n = 19). This undermines the generalizability of the study. How was the sample size determined? Was any power analysis conducted prior the experiment?
• In the Introduction, the authors stated that “Courier service in Republic of Korea also achieved a revenue of approximately $6.68 billion in 2020, which is 18.4% increase over the previous year”. Please add the source for the information regarding the 2020 revenue and for the one regarding the revenue of the previous year.
• In the Introduction, the authors posited that “The number of packages couriered is about 3.37 billion that corresponds to 65 packages per person in 25 the same year”. Please add the source of this information.
• In the Introduction, the authors stated that “As courier service develops, the unit price per package continues to decline due to the stiff competition between courier companies, and thus the treatment of deliverers substantially deteriorates to reduce cost”. Please add the source of the information regarding the decline of unit price per package and possibly for the deterioration of deliverers treatment.
• In the Participants subsection, please clarify how participants were recruited for the study.
• In the Participants subsection, the authors mentioned a daily pay of $200, but they did not clarify the experiment duration in terms of days.
• Please give credit by citing the developers of the wristband in the Apparatus subsection.
• Information about the Standardized Nordic Questionnaire (SNQ) and the Visual Analogue Scale (VAS) are not complete. For the SNQ and VAS, please report the number of items, the explored domains, and the psychometric properties (e.g., Cronbach’s alpha). Also, the authors should clarify the reasons for which they have chosen these instruments rather than other available ones by referring to the existing literature.
• In the Informed Consent Statement, the authors stated that “Written informed consent has been obtained from the patient(s) to publish this paper”. Which patients are the authors referring to?
• In the Heart rate reserve subsection, the authors did not clarify the meaning of the heart rate reserve parameter. Please also clarify the properties of the equation and not only the meaning of its terms. For instance, what type of values are obtained from the equation? What do higher obtained values mean? The same points apply for the Metabolic equivalent of task subsection.
• Please in the results, report also the degrees of freedom for each test.
• The authors stated that from the Tukey HSD test, resting has significantly lower HRR than the other groups. Please include the results in the standard format. The same applies for the results of task on MET.
• Statistical corrections of the significance levels (e.g., Bonferroni correction) should be applied when conducing multiple comparisons on the same independent variable.
• Please report results of the Tukey HSD tests in the standard format.
• In the Discussion, the authors stated that “Although this study has not found any statistical differences among task types, both HRR and MET show that the tasks of delivering as well as sorting inside a truck shows slightly higher workload than the others”. This conclusion goes against the results since the difference between tasks were non-significant. Please fix the discussion throughout to reflect the results and to be consistent on whether there are statistical differences or not. If from the results, no statistical difference emerges between two groups, we cannot say that the groups of interest are slightly different.
• At the end of the Discussion, the authors stated that they “could not obtain statistically significant conclusions by those variables due to the small number of the participants”. How do they know that if they had a bigger sample size, results would have been different? Please clarify.

 

Minor Issues

• The first sentence of the abstract is too lengthy for the reader. Please break the sentence into multiple ones to address the following points: background, aims, and measures/materials of interest.
• In the abstract, a conclusion sentence would be beneficial for the reader.
• I would suggest the authors to consider removing Figure 1, since it is not very informative for the readers.
• The authors stated that “The frequency and percentage of prevalence of musculoskeletal symptoms are obtained in the last 12 months, in the last 12 months interfering with work […]”. Please clarify, what is the difference between the symptoms obtained in the last 12 months and the ones obtained in the last 12 months interfering with work?
• In the Figures, please report significant differences with asterisks and explain the main results in the caption.

 

Final comments

Considering the small sample size, I would recommend the article for Rejection.

Author Response

Main message of the article

The article by Rim and Jung entitled “Workload evaluation of package deliverers focusing on pickup and delivery task in South Korea” quantified in terms of heart rate reserve, metabolic equivalent of task, standardized Nordic questionnaire, and visual analogue scale the workload of package deliverers (N = 20). The authors found significant effect of task (in particular resting) on the HRR and on MET levels. Cart usage is also found to impact MET. Furthermore, lower back and wrist/hand emerged to be the most affected body parts for the prevalence of musculoskeletal symptoms in the last 12 months and in the last 7 days.

 

General Judgment Comments

Although the idea behind the study is original, the article lacks some important information to be followed. For instance, original references are not always cited, results are not always reported in the standard format, and figures are not always self-explanatory. For instance, it is not possible to understand the main significant results by looking at the figures, since significance levels are not reported. The investigated variables are interesting and appropriate to explore the workload of package deliverers, but the sample size is too small (N = 20) to obtain any generalizable conclusion from the analysis, due to the low statistical power.

Response: The authors hope that the revised manuscript answers to the questions mentioned above.

 

Major Issues

The sample size of the study (N = 20) seems too small for any significant conclusion and the sample of participants is almost uniquely represented by males (n = 19). This undermines the generalizability of the study. How was the sample size determined? Was any power analysis conducted prior the experiment?

Response: The authors used 1122 data for each objective measure of HRR and MET by collecting them with a wristband and 180 data (20 participants * 9 body parts) for each subjective measure of SNQ and VAS. Hopefully, these data sets are somewhat enough to have some meaning results.

In the Introduction, the authors stated that “Courier service in Republic of Korea also achieved a revenue of approximately $6.68 billion in 2020, which is 18.4% increase over the previous year”. Please add the source for the information regarding the 2020 revenue and for the one regarding the revenue of the previous year.

Response: The reference was added.

In the Introduction, the authors posited that “The number of packages couriered is about 3.37 billion that corresponds to 65 packages per person in 25 the same year”. Please add the source of this information.

Response: The reference was added.

In the Introduction, the authors stated that “As courier service develops, the unit price per package continues to decline due to the stiff competition between courier companies, and thus the treatment of deliverers substantially deteriorates to reduce cost”. Please add the source of the information regarding the decline of unit price per package and possibly for the deterioration of deliverers treatment.

Response: The reference was added.

In the Participants subsection, please clarify how participants were recruited for the study.

Response: The sentence is changed to read “The experimenters personally contacted package deliverers and asked them to voluntarily participate in the study. A total of twenty deliverers (19 male and 1 female) were recruited in this study and each of them participated only for one day with a payment of $200.’

In the Participants subsection, the authors mentioned a daily pay of $200, but they did not clarify the experiment duration in terms of days.

Response: The sentence is changed to read ‘A total of twenty deliverers (19 male and 1 female) were recruited in this study and each of them participated only for one day with a payment of $200.’

Please give credit by citing the developers of the wristband in the Apparatus subsection.

Response: The name of a developer ‘Fitbit Inc.’ was added.

Information about the Standardized Nordic Questionnaire (SNQ) and the Visual Analogue Scale (VAS) are not complete. For the SNQ and VAS, please report the number of items, the explored domains, and the psychometric properties (e.g., Cronbach’s alpha). Also, the authors should clarify the reasons for which they have chosen these instruments rather than other available ones by referring to the existing literature.

Response: All the related paragraphs were rewritten in 2.2 Apparatus.

In the Informed Consent Statement, the authors stated that “Written informed consent has been obtained from the patient(s) to publish this paper”. Which patients are the authors referring to?

Response: patient is changed to participant.

In the Heart rate reserve subsection, the authors did not clarify the meaning of the heart rate reserve parameter. Please also clarify the properties of the equation and not only the meaning of its terms. For instance, what type of values are obtained from the equation? What do higher obtained values mean? The same points apply for the Metabolic equivalent of task subsection.

Response: All the related paragraphs were rewritten in 2.4.2. Heart rate reserve (HRR) and 2.4.3. Metabolic equivalent of task (MET).

Please in the results, report also the degrees of freedom for each test.

Response: All the degrees of freedom were added for F- and t-tests.

The authors stated that from the Tukey HSD test, resting has significantly lower HRR than the other groups. Please include the results in the standard format. The same applies for the results of task on MET.

Response: A table were added to show mean differences.

Statistical corrections of the significance levels (e.g., Bonferroni correction) should be applied when conducing multiple comparisons on the same independent variable.

Response: It is expected that the same results of statistically significant variables would be obtained after applying Bonferroni correction because the current p-values are small, most less than 0.003, enough to become significant.

Please report results of the Tukey HSD tests in the standard format.

Response: A table were added to show mean differences.

In the Discussion, the authors stated that “Although this study has not found any statistical differences among task types, both HRR and MET show that the tasks of delivering as well as sorting inside a truck shows slightly higher workload than the others”. This conclusion goes against the results since the difference between tasks were non-significant. Please fix the discussion throughout to reflect the results and to be consistent on whether there are statistical differences or not. If from the results, no statistical difference emerges between two groups, we cannot say that the groups of interest are slightly different.

Response: The sentence was changed to read “Although this study has not found any statistical differences in both HRR and MET among task types, the tasks of delivering as well as sorting inside a truck appear to be difficult because delivering requires handling many packages at once and walking a long distance, and sorting inside the truck requires loading packages into a cart placed outside by repetitively moving up and down the truck.”

At the end of the Discussion, the authors stated that they “could not obtain statistically significant conclusions by those variables due to the small number of the participants”. How do they know that if they had a bigger sample size, results would have been different? Please clarify.

Response: The sentence was deleted, and the conclusions section was added instead.

 

Minor Issues

The first sentence of the abstract is too lengthy for the reader. Please break the sentence into multiple ones to address the following points: background, aims, and measures/materials of interest.

In the abstract, a conclusion sentence would be beneficial for the reader.

Response: The concluding remark was added in the last sentence of the abstract to read ‘It would be recommended that the use of a cart has the advantage of handling many packages at once with less physical efforts of the deliverers.’

I would suggest the authors to consider removing Figure 1, since it is not very informative for the readers.

Response: If the reviewer does not mind, the authors would like to keep the figure because it may give some impression to readers in other countries about the working condition peculiar to South Korea.

The authors stated that “The frequency and percentage of prevalence of musculoskeletal symptoms are obtained in the last 12 months, in the last 12 months interfering with work […]”. Please clarify, what is the difference between the symptoms obtained in the last 12 months and the ones obtained in the last 12 months interfering with work?

Response: In 2.2 Apparatus section, the original questions of SNQ were added

In the Figures, please report significant differences with asterisks and explain the main results in the caption.

Response: Asterisks were added in Figures 3, 4, and 5.

 

Final comments

Considering the small sample size, I would recommend the article for Rejection.

Response: The authors used 1122 data for each objective measure of HRR and MET by collecting every minute with a wristband and 180 data (20 participants * 9 body parts) for each subjective measure of SNQ and VAS. Hopefully, these data sets are enough to have some meaning results.

Round 2

Reviewer 1 Report

The comments are that the authors improved pretty well. Congratulations.

Author Response

Thank you for your time to make the manuscript better.

Reviewer 3 Report

I still believe the sample size is a big limiting factor here, but if the editor considers it not a problem, it is up to the editor to decide

Author Response

Thank you for your time to make the manuscript better.