Diabetes Awareness, Treatment, and Control among Mexico City Residents

Round 1

Reviewer 1 Report

This manuscript details a large cohort of residents in Mexico city and their awareness of their diabetes status, receipt of appropriate treatments, and achieving of target goals. Overall I believe this manuscript has value in being published, though there are several issues that should be addressed in increase its value.

The following are a list of suggested changes:

Abstract:

1. The first section of the abstract doesn't describe the need for the research, nor its purposes or aims. This needs to be addressed and replace the text simply stating that the authors are 'describing the diabetes epidemic'.
2. The text about the 'rule of halves' gives the impression that the authors intend to test this rule as the primary item of importance, rather than what they actually did which was assess diabetes 1) awareness, 2) control, and 3) treatment rates.

Introduction: The introduction has some important points and interesting background to the issue, though requires some changes.

1. 'mega-country' is not a common term and should either be briefly explained or removed.
2. 'Awareness' is not used consistently throughout the manuscript, including in the introduction, with other terms like 'diagnosis rates' making this aspect confusing.
3. The authors need to justify why Mexico City is important to focus on when data on Mexico in general appears to be known.

Methods: the methods were very well described, it was easy to read and understand how the authors went about collecting data, diagnostic thresholds, and how the data was grouped/treated/analysed.

Results: The results were presented in a logical way and quite comprehensive and addressed each of the items raised in the methods.

1. The authors report that most (nearly 90%) of participants described themselves as 'very active' which goes against what was stated in the introduction and is also not raised in the discussion. This calls into question the validity of the data gathered and potential issues with the questionnaire used (made worse by the fact that there is no supplement which lists the questions asked by interviewers).
2. In Table 1 there are three education levels listed while the methods state that only two levels were used.
3. There is a very low % (<10%) of elderly participating in the survey, which may cause issues with applicability to the general population (aging population is mentioned in the introduction) - this should be acknowledged as a limitation in the discussion.
4. Significant ORs in Table 6 should be bolded to be consistent with the previous tables.

Discussion: The discussion needs a bit of work and is probably the weakest section of the manuscript.

1. A key problem is its similarity to the introduction in terms of not justifying why the research was done in the first place. Much of the discussion states that the results of the study align with previous research in Mexico and begs the question as to why this data needed to be collected in the first place.
2. The authors also state that 'the main limitations have been described throughout the discussion', which I disagree with. It isn't clear throughout the discussion what the authors consider the main limitations are and how these limitations may affect the validity or generalisability of the results. The main strengths should also be presented more clearly as I do believe the authors are underselling themselves somewhat on the potential importance of the data gathered.

Author Response

Reviewer 1

This manuscript details a large cohort of residents in Mexico city and their awareness of their diabetes status, receipt of appropriate treatments, and achieving of target goals. Overall I believe this manuscript has value in being published, though there are several issues that should be addressed in increase its value.

The following are a list of suggested changes:

Abstract:

1. The first section of the abstract doesn't describe the need for the research, nor its purposes or aims. This needs to be addressed and replace the text simply stating that the authors are 'describing the diabetes epidemic'.

Response=Thank you for the comment. We now clarify that the specific aim of the paper was to describe the ‘diabetes prevalence, awareness, treatment and control’ (Line 30-31).

1. The text about the 'rule of halves' gives the impression that the authors intend to test this rule as the primary item of importance, rather than what they actually did which was assess diabetes 1) awareness, 2) control, and 3) treatment rates.

Response=We have now removed the ‘rule of halves’ text from the abstract and replaced it by the texts mentioned above (Lines 30-31).

Introduction: The introduction has some important points and interesting background to the issue, though requires some changes.

1. 'mega-country' is not a common term and should either be briefly explained or removed.

Response=Thank you, we have now included a brief explanation for this term (Line 49)

1. 'Awareness' is not used consistently throughout the manuscript, including in the introduction, with other terms like 'diagnosis rates' making this aspect confusing.

Respones=We have now replaced all the terms (e.g. diagnosis rates) with awareness throughout the manuscript.

1. The authors need to justify why Mexico City is important to focus on when data on Mexico in general appears to be known.

Response= Thank you for the suggestion. We have now included a sentence justifying why it is important to understand diabetes awareness, treatment and control in  Mexico City and how this study provides novel information (Lines 86-92)

Methods: the methods were very well described, it was easy to read and understand how the authors went about collecting data, diagnostic thresholds, and how the data was grouped/treated/analysed.

Response= Thank you

Results: The results were presented in a logical way and quite comprehensive and addressed each of the items raised in the methods.

1. The authors report that most (nearly 90%) of participants described themselves as 'very active' which goes against what was stated in the introduction and is also not raised in the discussion. This calls into question the validity of the data gathered and potential issues with the questionnaire used (made worse by the fact that there is no supplement which lists the questions asked by interviewers).

Response= Thank you for highlighting this issue. We have clarified in the methods section that physical activity was measured using an internationally validated questionnaire, which has also shown good validity among Mexican adults (Lines 184-187). We have also included additional information in the limitations section highlighting the known over-reporting for self-reported physical activity (Lines 405-408).  

1. In Table 1 there are three education levels listed while the methods state that only two levels were used.

Response= Thank you for highlighting this mistake. We have now corrected the methods section to correctly state the number of education levels used (i.e., elementary school or less, secondary school, and high school or higher) (Lines 182-183)

1. There is a very low % (<10%) of elderly participating in the survey, which may cause issues with applicability to the general population (aging population is mentioned in the introduction) - this should be acknowledged as a limitation in the discussion.

Response= We have now included this issue as a limitation of the study (lines 401-405)

1. Significant ORs in Table 6 should be bolded to be consistent with the previous tables.

Response= Significant associations have now been highlighted using boded numbers in Table 6.

Discussion: The discussion needs a bit of work and is probably the weakest section of the manuscript.

1. A key problem is its similarity to the introduction in terms of not justifying why the research was done in the first place. Much of the discussion states that the results of the study align with previous research in Mexico and begs the question as to why this data needed to be collected in the first place.

Response= Thank you for the comment. We have now edited the discussion section to highlight how this study adds to the current knowledge of the diabetes epidemic in Mexico. Please refer to all highlighted sections in the discussion section for details.  

1. The authors also state that 'the main limitations have been described throughout the discussion', which I disagree with. It isn't clear throughout the discussion what the authors consider the main limitations are and how these limitations may affect the validity or generalisability of the results. The main strengths should also be presented more clearly as I do believe the authors are underselling themselves somewhat on the potential importance of the data gathered.

Response=Thank you for the suggestion. We have now expanded the limitations section and clarified the main strengths of the study (Lines 401-414)

Reviewer 2 Report

The Authors described the magnitude of the T2D epidemic in Mexico City including diagnosis rates, treatment targets and  treatment outcomes. They also aimed to identify subgroups of people with the highest prevalence of diabetes, as well as inequalities in diabetes diagnosis. This study indicates that stronger actions  should be implemented to reinforce diabetes screening locally.

In Tab 1, 1000 subjects present abdominal obesity. How was abdominal obesity diagnosed? If necessary insert in “Materials and Methods”. The overweight and obese subjects are 1014, so only 14 do not have abdominal obesity?

Table 2:  the OR values do not correspond to those mentioned in the text (lines 217-218, 222-223).

Table 3:  the OR values do not correspond to those mentioned at line 236.

Table 4: there is no correspondence with lines 243, 247 (p = 0.05), 250, 251, 254, 261.

The total number of subjects with HbA1C <7.0% (n.81) and with HbA1C> 7.0% ( 206) is not 297.

Table 5: the values do not correspond to those mentioned at lines 278,279,280.

Table 6: the values do not correspond to those mentioned on line 294.

Standardize Reference 35.

Reference 54 must be inserted in the text.

Author Response

Reviewer 2

The Authors described the magnitude of the T2D epidemic in Mexico City including diagnosis rates, treatment targets and  treatment outcomes. They also aimed to identify subgroups of people with the highest prevalence of diabetes, as well as inequalities in diabetes diagnosis. This study indicates that stronger actions  should be implemented to reinforce diabetes screening locally.

In Tab 1, 1000 subjects present abdominal obesity. How was abdominal obesity diagnosed? If necessary insert in “Materials and Methods”. The overweight and obese subjects are 1014, so only 14 do not have abdominal obesity?

R= We have now included the procedures for measuring abdominal obesity in the methods section (Lines192-195). As noted, abdominal obesity is independent of BMI measures and thus, participants may have normal BMI and abdominal obesity.

Table 2:  the OR values do not correspond to those mentioned in the text (lines 217-218, 222-223).

R= Thank you for highlighting this mistake. We have now corrected the OR in the text to correspond Table 2 (Lines 229-239)

Table 3:  the OR values do not correspond to those mentioned at line 236.

R= Thank you for highlighting this mistake. We have now corrected the OR in the text to correspond Table 3 (Lines 250-253)

Table 4: there is no correspondence with lines 243, 247 (p = 0.05), 250, 251, 254, 261.

R= Thank you for highlighting this mistake. We have now corrected the numbers in the text to correspond Table 4(Lines 258-276)

The total number of subjects with HbA1C <7.0% (n.81) and with HbA1C> 7.0% ( 206) is not 297.

R= Thank you for highlighting this mistake. Table 4 has been corrected and now the number of subjects with HbA1C <7.0% (n.81) and with HbA1C> 7.0% ( 216) adds 297

Table 5: the values do not correspond to those mentioned at lines 278,279,280.

R= Thank you for highlighting this mistake. We have now corrected the numbers in the text to correspond Table 5 (Lines 290-295)

Table 6: the values do not correspond to those mentioned on line 294.

R= Thank you for highlighting this mistake. We have now corrected the numbers in the text to correspond Table 6 (Lines 301-308)

Standardize Reference 35.

R=We have now included reference 35 (now reference 39) in table 2 in the standard way (i.e., using the reference manager). This is the only section where we identified reference 35 was inserted without the manager.

Reference 54 must be inserted in the text.

R= Thank you for identifying this mistake. We have eliminated this reference, since the Friedwald equation was not used for this version.