Peer Review History

Original SubmissionMay 28, 2019
Decision Letter - Adya Misra, Editor

Dear Dr. Luk,

Thank you very much for submitting your manuscript "Trends on incidence of type 1 and type 2 diabetes in Hong Kong, China: Analysis of the Hong Kong Diabetes Surveillance Database" (PMEDICINE-D-19-01907) for consideration at PLOS Medicine.

Your paper was evaluated by a senior editor and discussed among all the editors here. It was also discussed with an academic editor with relevant expertise, and sent to independent reviewers, including a statistical reviewer. The reviews are appended at the bottom of this email and any accompanying reviewer attachments can be seen via the link below:

[LINK]

In light of these reviews, I am afraid that we will not be able to accept the manuscript for publication in the journal in its current form, but we would like to consider a revised version that addresses the reviewers' and editors' comments. Obviously we cannot make any decision about publication until we have seen the revised manuscript and your response, and we plan to seek re-review by one or more of the reviewers.

In revising the manuscript for further consideration, your revisions should address the specific points made by each reviewer and the editors. Please also check the guidelines for revised papers at http://journals.plos.org/plosmedicine/s/revising-your-manuscript for any that apply to your paper. In your rebuttal letter you should indicate your response to the reviewers' and editors' comments, the changes you have made in the manuscript, and include either an excerpt of the revised text or the location (eg: page and line number) where each change can be found. Please submit a clean version of the paper as the main article file; a version with changes marked should be uploaded as a marked up manuscript.

In addition, we request that you upload any figures associated with your paper as individual TIF or EPS files with 300dpi resolution at resubmission; please read our figure guidelines for more information on our requirements: http://journals.plos.org/plosmedicine/s/figures. While revising your submission, please upload your figure files to the PACE digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email us at PLOSMedicine@plos.org.

We expect to receive your revised manuscript by Sep 23 2019 11:59PM. Please email us (plosmedicine@plos.org) if you have any questions or concerns.

***Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.***

We ask every co-author listed on the manuscript to fill in a contributing author statement, making sure to declare all competing interests. If any of the co-authors have not filled in the statement, we will remind them to do so when the paper is revised. If all statements are not completed in a timely fashion this could hold up the re-review process. If new competing interests are declared later in the revision process, this may also hold up the submission. Should there be a problem getting one of your co-authors to fill in a statement we will be in contact. YOU MUST NOT ADD OR REMOVE AUTHORS UNLESS YOU HAVE ALERTED THE EDITOR HANDLING THE MANUSCRIPT TO THE CHANGE AND THEY SPECIFICALLY HAVE AGREED TO IT. You can see our competing interests policy here: http://journals.plos.org/plosmedicine/s/competing-interests.

Please use the following link to submit the revised manuscript:

https://www.editorialmanager.com/pmedicine/

Your article can be found in the "Submissions Needing Revision" folder.

To enhance the reproducibility of your results, we recommend that you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. For instructions see http://journals.plos.org/plosmedicine/s/submission-guidelines#loc-methods.

Please ensure that the paper adheres to the PLOS Data Availability Policy (see http://journals.plos.org/plosmedicine/s/data-availability), which requires that all data underlying the study's findings be provided in a repository or as Supporting Information. For data residing with a third party, authors are required to provide instructions with contact information for obtaining the data. PLOS journals do not allow statements supported by "data not shown" or "unpublished results." For such statements, authors must provide supporting data or cite public sources that include it.

We look forward to receiving your revised manuscript.

Sincerely,

Clare Stone, PhD, Acting Editor-in-Chief

for

Adya Misra

Senior Editor

PLOS Medicine

plosmedicine.org

-----------------------------------------------------------

Requests from the editors:

We note there are some substantial issues to be resolved as highlighted by the referees. Please also address the following points:

Title – I wonder if a clearer study design could be used for the 2nd part of the title?

Abstract – there should be 3 sections: Background, Methods and Findings, Conclusions- please recast; Please quantify any results related to data with 95%Cis and p values; please provide a sentence on the limitations of the study as the final sentence of the ‘Methods and Findings section; please do add some summary level demograhic information;

Data – you say that no access is allowed – not even for users who meet requirements?

At this stage, we ask that you include a short, non-technical Author Summary of your research to make findings accessible to a wide audience that includes both scientists and non-scientists. The Author Summary should immediately follow the Abstract in your revised manuscript. This text is subject to editorial change and should be distinct from the scientific abstract. Please see our author guidelines for more information: https://journals.plos.org/plosmedicine/s/revising-your-manuscript#loc-author-summary

Please use square brackets for refs in the main text.

Line 113 – type 1 or 2?

Line 167 – please define diabetes codes

Line 177- define how diabetes is defined – what measure?

Line 199- I am confused by this sentence. Please clarify ‘Of 778,051 people captured in the HKDSD, we excluded 33,916 people with diabetes codes but not fulfilled other criteria of diabetes.’

Throughout you tend to fall back on describing simply diabetes, as this paper is about type 1 and 2, please be careful to always state which(or if both)

The word youth seems a little odd, please instead say people under 20 years of age

Figure 1 – can I suggest you use different colours instead of 3 variations of blue

Please use the "Vancouver" style for reference formatting, and see our website for other reference guidelines https://journals.plos.org/plosmedicine/s/submission-guidelines#loc-references. For example 6 names and then et al.

Mian text – is it possible to provide some information perhaps in table for – adding to one of the current tables – with more participant characteristics, eg BMI, married, smoking etc…

Please provide a STROBE reporting checklist

Do you have a prespecified analysis plan, if so please provide as a Supp file and a call out in the methods to it. If no plan exists, please state when the analyses were planned in relation to data analysis.

Comments from the reviewers:

Reviewer #1: I confine my remarks to statistical aspects of this paper. Unfortunately, I have some major issues that need to be resolved before I can recommend publication.

First, joinpoint analysis needs to be described and its use needs to be justified. It's a fairly obscure method and I had trouble finding literature describing it, but it appears to be a restricted linear spline method. However, while I do like the use of spline models, there are reasons to prefer restricted cubic splines. And spline methods are a) Well known and b) Implemented in popular software including R and SAS, rather than relying on specialized software.

Second, the results of the regression analysis don't seem to be included. Are the figures the results of the analysis? Are there other results? What about parameter estimates?

Third, categorizing age is almost surely a mistake. Use age as "number of years".

More specific comments:

Line 169 - 173 Something very strange is happening here. Perfect results for under 20 and then really bad results for over 20 make me suspicious that something is going wrong somewhere or, perhaps there are very few people under 20 with type I diabetes, which could lead to overfitting. The authors note that 103 people in HKDR had type I and it seems like about 1/3 were under 20 (although this doesn't seem to be explicitly stated).

Line 210 and other places. The authors state that many trends were linear, apparently from testing a model that had year as a linear effect on rate. But the fact that a linear trend is statistically significant does not mean the trend was linear, it just just means a straight line is a better fit than a null model. The tables and the graphs show that the trends were not linear at all - they went up and down in a complex pattern.

Table 1 may not be needed. It seems to duplicate the material from the graphs, which are easier to interpret. If Table 1 is kept, then the AAPC and the p value should be removed - they are misleading.

The age categories for the figures don't match the age caegories for the table - it's unclear why not, or what was actually included in the model - age as 0-20, 20-40 etc or age as 0-4, 5-9 etc or age as integer or what.

Peter Flom

Reviewer #2: This is a well written and clear paper that is of importance understanding diabetes epidemiology in this region of the world.

I have a number of recommendations to improve the manuscript.

1. Study population line 129. Please comment in limitations section further about diagnosing diabetes by HbA1c alone in chidlren. Please see Nowicka P, Santoro N, Liu H et al (2011) Utility of hemoglobin A(1c) for diagnosing prediabetes and diabetes in obese children and adolescents. Diabetes Care 34: 1306-11

2. Study population line 135. Please comment about why 1 day was chosen, is this sufficient time for a diagnosis of diabetes to be made e.g. revised diagnosis and subsequently drugs quickly stopped?

3. Study population line 159. Please comment specifically in the limitations section about the lack of islet cell antibodies for diagnosising T1DM in children. This is often crucial to distinguish T1 from T2 in children especially in absence of c peptide/insulin and in a population of T1 who may be increasingly overweight. Please see diagnosistic criteria used for T2DM in this recent study Candler TP, Mahmoud O, Lynn RM et al (2018a) Continuing rise of type 2 diabetes incidence in children and young people in the UK. Diabet Med 35: 737-44.

4. Figure 2 needs revising to better display the rising incidence in <20 year olds. In the current graph, the scale for this age group is not useful to see any change in trend. Suggest split figures for >20 and <20 to better show change incidence. This is a major finding in your study but is not displayed clearly in the results.

5. Line 285. Please expand further in the discussion as the cause of a reduction in incidence in women >60, can the authors speculate or suggest from other studies a cause for this?

6. Line 293. Please comment further regarding lower HbA1c at diagnosis across the time period 2002-2011 - is this statistically significant i.e. can you provide a p value/statistical test? Was there a specific public health campaign across this period suggesting people present earlier or a screening programme introduced? Please speculate as the the cause of this further in the discussion.

Reviewer #3: The author used national wide data to estimate trends of incidence of diabetes types. They could also look into prevalence of diabetes.

The authors presented data in adults and younger groups, it would be good to separately present data in adults and young adults and children

What are key drivers for such trends? The authors might have access to clinical information (e.g. BMI) and other sociodemographic data to investigate these?

Also it would be useful to provide diabetes incidence projection and possibly to calculate the burden attributable to diabetes (DALY) in this country.

Any attachments provided with reviews can be seen via the following link:

[LINK]

Revision 1

Attachments
Attachment
Submitted filename: Response to Reviewers_PLOSMED CK.docx
Decision Letter - Adya Misra, Editor

Dear Dr. Luk,

Thank you very much for re-submitting your manuscript "Secular trends on incidence of type 1 and type 2 diabetes in Hong Kong" (PMEDICINE-D-19-01907R1) for review by PLOS Medicine.

I have discussed the paper with my colleagues and the academic editor and it was also seen again by xxx reviewers. I am pleased to say that provided the remaining editorial and production issues are dealt with we are planning to accept the paper for publication in the journal.

The remaining issues that need to be addressed are listed at the end of this email. Any accompanying reviewer attachments can be seen via the link below. Please take these into account before resubmitting your manuscript:

[LINK]

Our publications team (plosmedicine@plos.org) will be in touch shortly about the production requirements for your paper, and the link and deadline for resubmission. DO NOT RESUBMIT BEFORE YOU'VE RECEIVED THE PRODUCTION REQUIREMENTS.

***Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.***

In revising the manuscript for further consideration here, please ensure you address the specific points made by each reviewer and the editors. In your rebuttal letter you should indicate your response to the reviewers' and editors' comments and the changes you have made in the manuscript. Please submit a clean version of the paper as the main article file. A version with changes marked must also be uploaded as a marked up manuscript file.

Please also check the guidelines for revised papers at http://journals.plos.org/plosmedicine/s/revising-your-manuscript for any that apply to your paper. If you haven't already, we ask that you provide a short, non-technical Author Summary of your research to make findings accessible to a wide audience that includes both scientists and non-scientists. The Author Summary should immediately follow the Abstract in your revised manuscript. This text is subject to editorial change and should be distinct from the scientific abstract.

We expect to receive your revised manuscript within 1 week. Please email us (plosmedicine@plos.org) if you have any questions or concerns.

We ask every co-author listed on the manuscript to fill in a contributing author statement. If any of the co-authors have not filled in the statement, we will remind them to do so when the paper is revised. If all statements are not completed in a timely fashion this could hold up the re-review process. Should there be a problem getting one of your co-authors to fill in a statement we will be in contact. YOU MUST NOT ADD OR REMOVE AUTHORS UNLESS YOU HAVE ALERTED THE EDITOR HANDLING THE MANUSCRIPT TO THE CHANGE AND THEY SPECIFICALLY HAVE AGREED TO IT.

Please ensure that the paper adheres to the PLOS Data Availability Policy (see http://journals.plos.org/plosmedicine/s/data-availability), which requires that all data underlying the study's findings be provided in a repository or as Supporting Information. For data residing with a third party, authors are required to provide instructions with contact information for obtaining the data. PLOS journals do not allow statements supported by "data not shown" or "unpublished results." For such statements, authors must provide supporting data or cite public sources that include it.

If you have any questions in the meantime, please contact me or the journal staff on plosmedicine@plos.org.

We look forward to receiving the revised manuscript by Dec 23 2019 11:59PM.

Sincerely,

Clare Stone, PhD

Managing Editor

PLOS Medicine

plosmedicine.org

------------------------------------------------------------

Requests from Editors:

Title- in order to adhere to PLOS Medicine style guide, your title must contain a study descriptor. Please revise to “Secular trends on incidence of type 1 and type 2 diabetes in Hong Kong: a retrospective cohort study”

Data availability- The Data Availability Statement (DAS) requires revision. For each data source used in your study: a) If the data are freely or publicly available, note this and state the location of the data: within the paper, in Supporting Information files, or in a public repository (include the DOI or accession number). b) If the data are owned by a third party but freely available upon request, please note this and state the owner of the data set and contact information for data requests (web or email address). Note that a study author cannot be the contact person for the data. c) If the data are not freely available, please describe briefly the ethical, legal, or contractual restriction that prevents you from sharing it. Please also include an appropriate contact (web or email address) for inquiries (again, this cannot be a study author).

Abstract- 95% CI is okay, we do not need the words “confidence interval” as this is a standard term

Abstract line 81 should be “subject” not “subjected”

Abstract conclusions- both sentences are very similar and there is no indication what is meant by youth, young adults or older adults. Please specify age groups and could it be rephrased to “There was an increase in incidence of both Type 1 and Type 2 diabetes between the age of _ and _ but remained stable in the age group __ ”.

Author summary please reword “over half is coming from Asia” to “over half of the diabetes population come from Asian countries” or similar

Author summary- please remove “ calls for preventative actions …” as your study determined the trends and the significance of your findings needs a better explanation

Introduction- I don’t think we have a Type 2 diabetes pandemic. I appreciate the rates are increasing and there are public health concerns but please tone down.

Introduction- please change “over-weight” to “overweight”

Methods- please mention earlier in the methods section whether your study had a prospective analysis plan. If not, please provide reasons

Page 24 Line 414- please remove the word “destined” and consider more appropriate language for a scientific article

Page 24 please provide a reference to support “women are generally more receptive…”

Please ensure you use consistent terminology for ethnicity throughout the text- such as “east Asian” or “Chinese” as they are both used interchangeably.

Page 27, please consider revising the limitation section to remove the words “firstly” “fifthly” etc as these are not appropriate for a research article

Throughout the text, when you say older or younger adults please add the age group referred to for additional clarity

Line 161 – does this need updating? 250.xx

Line 429 “marked reduction” – please be more specific and give a %decline

The STROBE checklist cannot contain page or line numbers as these change during the publication process. Please reference the appropriate paragraphs/sections

Comments from Reviewers:

Reviewer #1: The authors have addressed my concerns and I now recommend publication.

Peter Flom

Any attachments provided with reviews can be seen via the following link:

[LINK]

Revision 2

Attachments
Attachment
Submitted filename: Response to Reviewers_PLOSMED_second_revision.docx
Decision Letter - Adya Misra, Editor

Dear Dr Luk,

On behalf of my colleagues and the academic editor, Dr. Sanjay Basu, I am delighted to inform you that your manuscript entitled "Secular trends in incidence of type 1 and type 2 diabetes in Hong Kong: a retrospective cohort study" (PMEDICINE-D-19-01907R2) has been accepted for publication in PLOS Medicine.

PRODUCTION PROCESS

Before publication you will see the copyedited word document (in around 1-2 weeks from now) and a PDF galley proof shortly after that. The copyeditor will be in touch shortly before sending you the copyedited Word document. We will make some revisions at the copyediting stage to conform to our general style, and for clarification. When you receive this version you should check and revise it very carefully, including figures, tables, references, and supporting information, because corrections at the next stage (proofs) will be strictly limited to (1) errors in author names or affiliations, (2) errors of scientific fact that would cause misunderstandings to readers, and (3) printer's (introduced) errors.

If you are likely to be away when either this document or the proof is sent, please ensure we have contact information of a second person, as we will need you to respond quickly at each point.

PRESS

A selection of our articles each week are press released by the journal. You will be contacted nearer the time if we are press releasing your article in order to approve the content and check the contact information for journalists is correct. If your institution or institutions have a press office, please notify them about your upcoming paper at this point, to enable them to help maximize its impact.

PROFILE INFORMATION

Now that your manuscript has been accepted, please log into EM and update your profile. Go to https://www.editorialmanager.com/pmedicine, log in, and click on the "Update My Information" link at the top of the page. Please update your user information to ensure an efficient production and billing process.

Thank you again for submitting the manuscript to PLOS Medicine. We look forward to publishing it.

Best wishes,

Adya Misra, PhD

Senior Editor

PLOS Medicine

plosmedicine.org

Open letter on the publication of peer review reports

PLOS recognizes the benefits of transparency in the peer review process. Therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. Reviewers remain anonymous, unless they choose to reveal their names.

We encourage other journals to join us in this initiative. We hope that our action inspires the community, including researchers, research funders, and research institutions, to recognize the benefits of published peer review reports for all parts of the research system.

Learn more at ASAPbio .