Review Reports - Health Status and Use of Healthcare Services of Undocumented Migrant Sex Workers in Catalonia: A Descriptive Study Using Administrative Registries

Round 1

Reviewer 1 Report (New Reviewer)

Comments and Suggestions for Authors

I have analysed the manuscript titled "Health status and use of healthcare services by undocumented migrant sex workers in Catalonia: a retrospective cohort study" using administrative registries by the authors.

The topic is relevant, as it will discover the use of healthcare services by undocumented migrant sex workers and their health statuses in Catalonia.

However, I have a few major concerns as follows:

The title does not tally with what was described in the methodology. The study design was a descriptive observational study of UMSWs instead of a cohort study. Please improve.

Abstract:

Please provide relevant statistical values, i.e., p-value and CIs. The conclusion is vague and lacks scientific rigour. What can be proposed for the future?

Introduction:

The target population, UMSWs, has not been well elaborated. It appears at the end of the introduction part. The gap is missing, as the “sex worker” is a broad term. The authors should explicitly explore how administrative registries, for example, MBDS and eCAP, are suitable for them.

In addition, please justify why regional subgrouping is proposed in this study. Why region of origin is an important issue here. I know some of the information is there, but please link it with the origin of the UMSWs involved.

Please tighten the objectives and explicitly provide each of them at the end of the section.

Methodology:

It has been mentioned that sex (legal gender as reflected in official documents), age, annual income bracket, and benefits received from the Central Registry were retrieved, but the data has not been presented. Please clarify.

Please be consistent with the terms “emergency” and “emergency services”, as the service can be offered in the primary care setting.

It is clearly stated that the consent was not required, but it is very important to state whether REC/IRB has issued an exemption, and this should be documented with a reference number.

About “If an UMSW left Catalonia during the first year…” Please explicitly state in the result section how many of them are affected.

The current format does not clearly present the independent and dependent variables, making it difficult to understand the relationship between them. Please provide a conceptual framework to illustrate the relationship between those variables.

What is SES? Where are the results of SES?

The definitions of “chronic” and “non-chronic” are weak. Please justify with references.

The incidence and prevalence of some variables should be explicitly explained. Please provide the details of the denominators for each variable. The data is missing. The unit for the incidence, i.e., the number of events by 100 person-years, was described by the authors, yet the results are presented in percentages. Please clarify.

Results:

The general characteristics are not well covered, as some variables are missing, such as income, SES, and benefits. The number of subjects from each of the regions must be provided to gauge whether adequate representatives from each region are employed.

Please add in the age group in years.

Some of the data on the origin of regions is too small; merging some would help subgroup analysis. For example, data from North America with Europe/Central Asia should be combined if possible.

Table 2 may be redundant unless there is a justification for its inclusion.

About “Nine hundred and fifty-seven (57.3%) women and men contacted one or more primary care services…” Where are these figures? I could not locate them in any tables.

Table 4: Please clarify what this “**” means.

Table 4: please be consistent with the terms “draws” and “extractions”.

Please improve the significant findings with the effect sizes plus 95% CIs.

Could you please clarify why multiple logistic regressions were not performed? Please clarify.

Discussion:

The claim that UMSWs “do not use healthcare services as often as legal residents or other undocumented migrants” has been compared to external figures (≈80% PC; 35% ED; 61%/27.7%). I wonder whether your findings have been adjusted, and the analysis is merely descriptive. The differences could reflect the combination of age and sex or SES rather than UMSW status per se. Please clarify.

It was classified that the incidences of HCV/HBV/HPV/candidiasis/syphilis were “high”, but the claim is not apparent. How did you compare those data?

Conclusion:

The different origins of UMSWs have not been critically concluded. Do you think a targeted approach is necessary?

Comments on the Quality of English Language

Please check minor issues in the sentence construction and grammatical errors.

Author Response

Reviewer 1

The topic is relevant, as it will discover the use of healthcare services by undocumented migrant sex workers and their health statuses in Catalonia.

However, I have a few major concerns as follows:

QUESTION: The title does not tally with what was described in the methodology. The study design was a descriptive observational study of UMSWs instead of a cohort study. Please improve.

ANSWER: Thank you very much for your observation. Indeed, this is a cross-sectional (descriptive) observational study, and we have accordingly modified the title. See title.

Abstract:

QUESTION: Please provide relevant statistical values, i.e., p-value and CIs. The conclusion is vague and lacks scientific rigour. What can be proposed for the future?

ANSWER: Thank you very much for your valuable feedback. The p-values associated with the tests have been added to the abstract, highlighting where significant differences were found. Indeed, the previous conclusion was not sufficiently clear; upon revision, it has been modified to the following sentence: “Facilitating early diagnosis and improving access to healthcare resources among key populations such as Men Sex Men or Transgender Women can be achieved through interventions such as community-led point-of-care testing, which increases the frequency of HIV and STD screening and may also prove effective among UMSWs”. See lines 24-27.

Introduction:

QUESTION: The target population, UMSWs, has not been well elaborated. It appears at the end of the introduction part. The gap is missing, as the “sex worker” is a broad term. The authors should explicitly explore how administrative registries, for example, MBDS and eCAP, are suitable for them.

ANSWER: We appreciate the reviewer’s valuable comment. In the introductory section, we refer to the Functional Plan for Access to Healthcare in Catalonia for Undocumented Migrants Engaged in Prostitution, implemented by the NGO (Red Cross). In the methodology section, we clarify how the researchers involved in the study were able to access these data in a pseudo-anonymized format. Therefore, this aspect pertains more to the procedures for data access rather than to gender registration within the different databases (CMBDs, eCAP).

QUESTION: In addition, please justify why regional subgrouping is proposed in this study. Why region of origin is an important issue here. I know some of the information is there, but please link it with the origin of the UMSWs involved.

ANSWER: Dear reviewers, the following lines were added: “Among the general population in Catalonia, differences in healthcare use is observed depending on the region of origin [25], and in other studies among SW in Catalonia (including migrant sex workers) differences in condom use and HIV prevalence were observed depending on region of origin [22]”. See lines 90-93.

Please tighten the objectives and explicitly provide each of them at the end of the section.

Methodology:

QUESTION: It has been mentioned that sex (legal gender as reflected in official documents), age, annual income bracket, and benefits received from the Central Registry were retrieved, but the data has not been presented. Please clarify.

ANSWER: We apologize for the error. In a previous version of the manuscript, we included a classification according to socioeconomic level. However, together with the co-authors, we have decided to remove this classification, as—after consulting with the registry service—we confirmed that socioeconomic level is automatically assigned to undocumented migrants under a fictitious category. This occurs because they lack legalized employment and are not included in the labor or social security systems; the classification is used solely for the purpose of granting access to healthcare services.Therefore, any analysis based on this variable would be flawed and could lead to misleading conclusions. The remaining references to this variable that were inadvertently left in the text have now been deleted. We sincerely thank you again for your careful review and valuable observations.

QUESTION: Please be consistent with the terms “emergency” and “emergency services”, as the service can be offered in the primary care setting.

ANSWER: Thank you very much for this observation. You are right that it could lead to misunderstandings. To avoid them, we have adopted the term “hospital emergency services” to refer to emergency care within the hospital setting, and the term “emergency at primary care” in definitions, using simply “emergency” in the results section when referring to the different primary care units. These changes have been implemented consistently throughout all relevant sections of the manuscript (text and tables). See Results, Discussion sections and Tables 3 and 4.

QUESTION: It is clearly stated that the consent was not required, but it is very important to state whether REC/IRB has issued an exemption, and this should be documented with a reference number.

ANSWER: Our study is based on the reutilization of data contained in administrative registries of the Department of Health of Catalonia.

The treatment of clinical and health data by AQuAS is regulated by the Organic Law 3/2018, of December 5, on the protection of personal data and guarantee of digital rights (LOPDGDD); the General Data Protection Regulation (RGPD) (EU) 2016/679, of April 27; as well as the considerations issued by the Catalan Data Protection Authority (APDCAT). In all cases, the reuse of clinical and health data of natural persons is allowed for epidemiological, clinical, or health research purposes. For this research, a pseudo anonymization process of the personal identification code called NIA was used. AQuAS has no need to ask REC for an exemption.

As workers at AQuAS we are never given access to identifiable information. Moreover, the study did not involve any data collection, requiring neither human participants nor patient consent. For that reason, and due to the use of existing anonymised data, the study was exempt from institutional review committee approval. It is the standard way of proceeding in the Catalan healthcare administration to systematically check the quality of the healthcare providers and assess the effectiveness of the deployed policies.

QUESTION: About “If an UMSW left Catalonia during the first year…” Please explicitly state in the result section how many of them are affected.

ANSWER: The reviewer is right. We added some details: “If an UMSW left Catalonia during the first year (12.3%), the corresponding outcome variables were estimated proportionally for a one-year period.” See lines 112-113..

QUESTION: The current format does not clearly present the independent and dependent variables, making it difficult to understand the relationship between them. Please provide a conceptual framework to illustrate the relationship between those variables. What is SES? Where are the results of SES?

ANSWER: We apologize for the error. In a previous version of the manuscript, we included a classification according to socioeconomic level. However, together with the co-authors, we have decided to remove this classification, as—after consulting with the registry service—we confirmed that socioeconomic level is automatically assigned to undocumented migrants under a fictitious category. This occurs because they lack legalized employment and are not included in the labor or social security systems; the classification is used solely for the purpose of granting access to healthcare services.Therefore, any analysis based on this variable would be flawed and could lead to misleading conclusions. The remaining references to this variable that were inadvertently left in the text have now been deleted. We sincerely thank you again for your careful review and valuable observations.

QUESTION: The definitions of “chronic” and “non-chronic” are weak. Please justify with references.

ANSWER:The following definition was added to improve comprehension of the STDs classification into chronic/non-chronic: Finally, the selected STDs were defined as “chronic” or “non-chronic”... depending on the STI being “curable” or not as per WHO definition reference: Sexually transmitted infections (STIs). See lines 166-169.

QUESTION: The incidence and prevalence of some variables should be explicitly explained. Please provide the details of the denominators for each variable. The data is missing. The unit for the incidence, i.e., the number of events by 100 person-years, was described by the authors, yet the results are presented in percentages. Please clarify.

ANSWER: Thanks. Fully agreed, as the table did not specify this correctly. The abbreviation py has been added, along with the corresponding table footnote: py: per 100 person-years. See Table 5.

Results:

QUESTION: The general characteristics are not well covered, as some variables are missing, such as income, SES, and benefits. The number of subjects from each of the regions must be provided to gauge whether adequate representatives from each region are employed.

ANSWER: Thank you very much for this remark. We have revised the text to include both the relative (%) and absolute (N) frequencies of the different regions in order to better assess the impact of the findings. The revised text now reads:

“The most common region of origin was Latin America and the Caribbean, representing 40.3% (670) of the study population, followed by Europe and Central Asia at 34.0% (565), Sub-Saharan Africa at 23.1% (384), and the Middle East and North Africa at 1.2% (20), while the least common regions were North America, representing 0.1% (1), and East Asia and the Pacific at 1.0% (18).” See lines 180-184.

Regarding the socioeconomic level variable, as mentioned previously, this was due to an error.

QUESTION: Please add in the age group in years.

ANSWER: Thank you very much. It has been clearly specified in the tables that the variable age is expressed in years. See Tables 1 and Table 2.

QUESTION: Some of the data on the origin of regions is too small; merging some would help subgroup analysis. For example, data from North America with Europe/Central Asia should be combined if possible.

ANSWER: Unfortunately, this option is no longer available. In addition, we tried to stick to a common and widely spread classification such as the one from the World Bank rather than doing our own version depending on our data availability and accept the consequences of this decision as a study limitation. We apologise for the inconvenience.

QUESTION: Table 2 may be redundant unless there is a justification for its inclusion.

ANSWER: Thank you for your comment. However, we believe that Table 2, which is stratified by origin, age group, and sex, is important for this study.

QUESTION: About “Nine hundred and fifty-seven (57.3%) women and men contacted one or more primary care services…” Where are these figures? I could not locate them in any tables.
ANSWER: Thank you very much for pointing out these figures, which made us realize the error. The text should read nine hundred and fifty-three (953), and in parentheses, the percentage 57.3%. These data are shown in Table 3, where the same error also appeared (it previously indicated 53.1%).

QUESTION: Table 4: Please clarify what this “**” means.

ANSWER: Thank you very much for this remark. Since no subject meets that condition, no summary statistical measure can be calculated—neither a mean nor an interquartile range in this case. This has been indicated in the table footnote as: **** This value cannot be computed. See Table 4.

QUESTION: Table 4: please be consistent with the terms “draws” and “extractions”.

ANSWER: Thank you very much for this remark. Fixed, now only “extractions” word is used.

QUESTION: Please improve the significant findings with the effect sizes plus 95% CIs.

ANSWER: Thank you for your comment. We have considered that, since our data refer to the use of public healthcare services and the study includes all individuals who obtained their health card through the specific Functional Plan—thus, without any kind of sampling from a particular population—the calculation of a sample size is not applicable. Furthermore, as this is a descriptive study, we have chosen not to include confidence intervals in order to simplify the presentation.

QUESTION: Could you please clarify why multiple logistic regressions were not performed? Please clarify.

ANSWER: While it would have been possible to perform logistic models for healthcare service utilization, prevalence models for chronic diseases, and Poisson models for incidences, we found that the number of infection cases was relatively low. Moreover, when stratified by country of origin (without grouping), the statistical power was not adequate. The only feasible analysis would have involved using age group as the exposure variable; however, the age distribution was very similar across groups, and we believe that any differences would not have been meaningful in practice. For all these reasons, we chose to conduct a purely descriptive study.

Discussion:

QUESTION: The claim that UMSWs “do not use healthcare services as often as legal residents or other undocumented migrants” has been compared to external figures (≈80% PC; 35% ED; 61%/27.7%). I wonder whether your findings have been adjusted, and the analysis is merely descriptive. The differences could reflect the combination of age and sex or SES rather than UMSW status per se. Please clarify.

ANSWER: The data are compared without any form of adjustment, and the purpose is precisely to highlight that they make less use of health services than undocumented migrants, taking advantage of the fact that we have access to these data from a previous study.

QUESTION: It was classified that the incidences of HCV/HBV/HPV/candidiasis/syphilis were “high”, but the claim is not apparent. How did you compare those data?

ANSWER: Thank you for the comment. It is true that, since we did not compare them with any other specific group or context, it is not appropriate to use the term “high.” Therefore, we have adopted the terminology “non-negligible. See lines 280-281.

Conclusion:

QUESTION: The different origins of UMSWs have not been critically concluded. Do you think a targeted approach is necessary?

ANSWER: Due to study data limitations the authors consider that the discussion of results about regions of origin does lack the solidity and consistency to be managed in a targeted approach. further research with a more solid data quality and availability focusing on region of origin would be convenient, potentially providing deeper insights on UMSW healthcare usage.

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

The aim of the paper is to present the health status and use of public healthcare services of undocumented migrant sex workers in Catalonia 2013-2018. The method is based on administrative data, which results in an objective view without the limitation of interviewing members of vulnerable groups. The topic is important, as being UM and SW together makes an intersectional combination. Being aware of the importance of the subject, the reviewer has some remarques which could make the text more clear, complete and consistent.

Abstract:

l. 18: “SW” or “UMSW”? I understand it relates to UMSW, therefore when I see just “SW” I am confused.

l. 23: “or other documented migrants” – this is not clear to me as in the Discussion, l. 243, you compare UMSW to “other undocumented migrants”. (BTW, are documented migrants not legal residents?)

Introduction:

l. 28: You start with the words: “in comparison with the general population…”, however I do not see this comparison. The next sentences only give us the numbers about healthcare use/access for SW, but there is no data about the general population(s) in these countries. In my opinion, a reference is needed for this first sentence.

l. 40: “all forms” – of what? Of discrimination? Not clear.

l. 47: “STIs” – in the previous part you explain STD, then STI should also be explained.

l. 47-48: the sentence without a verb.

You present the background relating to SW health issues, rights, vulnerability, then as the group described in the study, is UMSW, it would be good (in my opinion) to say something about the vulnerability of undocumented migrants. In line 56 you mention “migrants”, that’s correct, but UM are a specific group. In fact, being SW+UM is a specific situation, resulting in intersectional vulnerability, then adding one (separate) paragraph about UM situation would be helpful to show the large context. In some countries UMs have no access to healthcare services. The case of Catalonia, with the right to heath care, is presented in “materials and methods” section only, and in my opinion, something about this obligation of Public Health Agency of Catalonia could be included in the Introduction.

l. 56: “Unfortunately” – it does not sound good in an scientific article (in my opinion).

Materials and methods:

l. 95: “the activity” – you mean the activity within the public health sector?

l. 137: “SES” – is not explained.

l. 147: you define chronic and non-chronic STDs, however in the Results you do not use it these words anymore.

l.148: prevalences were estimated? Or calculated? IN the next paragraph you say it was calculated.

Results:

l. 170 – I do not see which part of the table refers to SES. I only see age groups and sex. Unless the file I received is not the proper one (with missing parts of the tables?).

Table 3:

“Mean primary care or specialist units (Median (IQR))”: is it about visits?

Discussion:

l. 252 – you refer to hospital services, but “hospital services” do not appear in the tables, could you, please specify, what is included in “hospital services”?

l. 300-301 – please correct “:”, “patters”? Or “patterns”? Should it be “as well” or “as well as”?

Conclusions:

The first paragraph, the remarques explaining why the method chosen is valuable: in my opinion, this could appear in the section describing methods, as this is not a conclusion from your study (in your study, you do not compare methods, surveys vs administrative data). Please rethink.

As the objective of the study was “to assess the differences according to region of origin”, some part(s) of the conclusions should refer to it. In my opinion, the conclusions now do not follow the study. You could include something about next steps needed (like an area for future research relating to UMSWs).

l.317: "in general" - as I understand, this is about general group of UMSWs, not "general local population"? This is not clear.

The Abbreviations section:

Only SW, AIDS and HIV are included. This is not clear why SW is explained both in the text (l. 29) and abbreviation section, while some other abbreviations are not explained at all. It looks like lack of consequence.

Author Response

Reviewer 2

Abstract:

QUESTION: l. 18: “SW” or “UMSW”? I understand it relates to UMSW, therefore when I see just “SW” I am confused.

ANSWER: We missed that typo, it was changed to UMSW. Thanks.

QUESTION: l. 23: “or other documented migrants” – this is not clear to me as in the Discussion, l. 243, you compare UMSW to “other undocumented migrants”. (BTW, are documented migrants not legal residents?)

ANSWER: Thank you for your comment. We had made an error in the wording of the abstract — we intended to refer to undocumented migrants. However, this paragraph has been removed, and following the suggestion of another reviewer, we have revised the conclusions to be more specific and to include the next steps. The revised text now reads as follows:

“Facilitating early diagnosis and improving access to healthcare resources among key populations such as men who have sex with men or transgender women can be achieved through interventions such as community-led point-of-care testing, which increases the frequency of HIV and STI screening and may also prove effective among UMSWs.” See lines 24-27.

Introduction:

QUESTION: l. 28: You start with the words: “in comparison with the general population…”, however I do not see this comparison.

ANSWER: Thank you for the remark. We have revised the text to illustrate this lower use of health services among female sex workers compared to the utilization observed in the general female population with the following paragraph “, for example, only 39% of female sex workers maintain antiretroviral treatment retention in Cambodia, compared to retention rates of around 70–85% in the general female population; in Uganda, they initiate treatment later than the general population”. See lines 39-41.

QUESTION: The next sentences only give us the numbers about healthcare use/access for SW, but there is no data about the general population(s) in these countries. In my opinion, a reference is needed for this first sentence.

ANSWER: Thank you again for your comment. However, since we have already revised the previous paragraph where the results are compared with the general population, we believe it is more appropriate to focus here solely on presenting the findings related to sex workers. This approach avoids overloading the introduction with data and, at the same time, facilitates a more straightforward (though nuanced) comparison with the results emerging from our study.

QUESTION: l. 40: “all forms” – of what? Of discrimination? Not clear.

ANSWER: You are totally righ, that was missing; we have now included “of discriminations.” Thank you very much. See line 49.

QUESTION: l. 47: “STIs” – in the previous part you explain STD, then STI should also be explained.

ANSWER: Thank you for the observation; the meaning has been specified.. See line 41.

QUESTION: l. 47-48: the sentence without a verb.

ANSWER: Thank you very much for your notice. We have incorporated the verb, and the resulting sentence now reads: “For example, the provision of tools for the prevention of STIs or the performance of health check-ups on a regular basis is lacking.”. See line 56..

QUESTION: You present the background relating to SW health issues, rights, vulnerability, then as the group described in the study, is UMSW, it would be good (in my opinion) to say something about the vulnerability of undocumented migrants. In line 56 you mention “migrants”, that’s correct, but UM are a specific group. In fact, being SW+UM is a specific situation, resulting in intersectional vulnerability, then adding one (separate) paragraph about UM situation would be helpful to show the large context. In some countries UMs have no access to healthcare services.

ANSWER:We fully agree with this observation. The main challenge we face is the scarcity — almost the absence — of comparative studies focusing on undocumented migrant sex workers. As a result, we must rely on research conducted with related populations who, however, do not necessarily experience this potential triple barrier to access — being migrants, undocumented, and engaged in sex work. These groups tend to remain largely invisible to institutional systems, particularly when it comes to conducting research studies.

QUESTION: The case of Catalonia, with the right to heath care, is presented in “materials and methods” section only, and in my opinion, something about this obligation of Public Health Agency of Catalonia could be included in the Introduction.

ANSWER: In Catalonia, all residents are granted universal public health-care coverage by law. See line 80.

QUESTION: l. 56: “Unfortunately” – it does not sound good in a scientific article (in my opinion).

ANSWER:Thank you very much for your comment. We have therefore opted for the word “Moreover” as it is more appropriate, and we have incorporated this change into the text accordingly. See line 64.

Materials and methods:

QUESTION: l. 95: “the activity” – you mean the activity within the public health sector?

ANSWER: Thanks. To make this clear, it has been specified as follows: “The activity within the public health sector of each UMSW was monitored for an entire year since they obtained the health card”. See lines 107-109.

QUESTION: l. 137: “SES” – is not explained.

QUESTION: l. 147: you define chronic and non-chronic STDs, however in the Results you do not use it these words anymore.

ANSWER: Words “chronic” and non chronic were added in the results paragraph for consistency. See lines 246-248.

QUESTION: l.148: prevalences were estimated? Or calculated? In the next paragraph you say it was calculated.

ANSWER: Thanks. Calculated is the correct term, changed. See line 167.

Results:

QUESTION: l. 170 – I do not see which part of the table refers to SES. I only see age groups and sex. Unless the file I received is not the proper one (with missing parts of the tables?).

Table 3:

QUESTION: “Mean primary care or specialist units (Median (IQR))”: is it about visits?

ANSWER: Thank you very much for your comment. Indeed, these refer to visits, and we have included the term “visits” in the table affected. See table 3.

Discussion:

QUESTION: l. 252 – you refer to hospital services, but “hospital services” do not appear in the tables, could you, please specify, what is included in “hospital services”?

ANSWER: Thank you very much for your comment. It was indeed necessary to specify that we were referring to "hospital emergency services," and we have now made this clarification in the text. See line 275.

QUESTION: l. 300-301 – please correct “:”, “patters”? Or “patterns”? Should it be “as well” or “as well as”?

ANSWER: Thank you very much. The text has now been corrected with the following paragraph: “In addition, the lack of morbidity data (i.e., general health status) as well as cultural patterns. See lines 224-225.

Conclusions:

QUESTION: The first paragraph, the remarques explaining why the method chosen is valuable: in my opinion, this could appear in the section describing methods, as this is not a conclusion from your study (in your study, you do not compare methods, surveys vs administrative data). Please rethink.

ANSWER: I believe we have different points of view. In this paragraph, we do not aim to explain why the chosen method is valuable. Rather, we describe, in a broad sense, the benefits of using administrative healthcare data and the potential of studies based on population-based administrative registries.

QUESTION: As the objective of the study was “to assess the differences according to region of origin”, some part(s) of the conclusions should refer to it. In my opinion, the conclusions now do not follow the study. You could include something about next steps needed (like an area for future research relating to UMSWs).

ANSWER: Completely accurate observation. Taking into account the cultural differences and the limited representativeness of certain regions, we have added the following paragraph to the conclusions as a potential line of future research:

"Nonetheless, it would be desirable to increase the statistical power in order to ascertain whether the observable differences among the various origins are truly meaningful rather than attributable to chance, ideally through the promotion of multicentre studies conducted in socio-economic, healthcare, and political contexts comparable to that of Spain."

QUESTION: l.317: "in general" - as I understand, this is about general group of UMSWs, not "general local population"? This is not clear.

ANSWER: Indeed, the sentence was not correctly written. It has been revised to: “The results regarding UMSWs’ healthcare use, and in relation to the different regions of origin in particular.” See line 341.

The Abbreviations section:

QUESTION: Only SW, AIDS and HIV are included. This is not clear why SW is explained both in the text (l. 29) and abbreviations section, while some other abbreviations are not explained at all. It looks like lack of consequence.

ANSWER: The abbreviations section has been improved. Please feel free to comment if you miss any abbreviation in this section and it will be added. We apologise for the lack of consistency. See lines 389-390.

Round 2

Reviewer 1 Report (New Reviewer)

Comments and Suggestions for Authors

All comments have been adequately addressed by the authors. Congratulations!

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

Thank you for the answers and detailed explanation of your perspective.

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

Comments and Suggestions for Authors

This manuscript presents an important and timely examination of the health status and utilization of healthcare services among undocumented migrant sex workers (UMSW) in Catalonia. As the authors rightly note in the introduction, sex workers—particularly those who are undocumented migrants—face substantial barriers to accessing healthcare. These barriers are both social, such as stigma and fear, and bureaucratic in nature.

Given the retrospective design of the study, the authors were understandably limited in their ability to explore the underlying reasons for these barriers in depth. Nevertheless, the manuscript provides valuable insights into healthcare service utilization and the incidence and prevalence of sexually transmitted infections (STIs), including HIV, among this vulnerable population.

The statistical methods employed are appropriate for the study’s objectives, and the results are clearly presented. However, I would like to offer a few specific comments:

Table 2 appears somewhat overcrowded and may benefit from being simplified or reorganized for clarity.
Table 5 seems out of place and may be redundant; the authors might consider omitting it or integrating its content more effectively into the text.

Questions and Comments for the Authors:

Line 235: Could you please clarify what “blood culture units” mean? The term is ambiguous in this context.
Lines 248–249: You mention differences in hospital utilization based on region of origin. However, without morbidity data, the significance of this finding is unclear. For example, if UMSW from the Middle East and North Africa have higher levels of illness compared to those from South America, it would naturally follow that they use hospital services more frequently. While I understand that stratification by health status may not have been feasible, this represents a significant limitation that should be more explicitly acknowledged.
Was the use of pre-exposure prophylaxis (PrEP) documented in the study? Is PrEP currently offered to UMSW in this setting?
Do you have a hypothesis or explanation for why people living with HIV (PLWH) in your cohort do not appear to utilize healthcare services more frequently than those without HIV?
Based on your findings, could you propose strategies or recommendations to improve healthcare access and utilization among UMSW?

Overall, this is a valuable contribution to the literature on migrant health and healthcare disparities. With some clarifications and additional discussion, particularly around limitations and implications, the manuscript can be further strengthened.

Comments on the Quality of English Language

I cannot comment about this

Author Response

Reviewer 1

The statistical methods employed are appropriate for the study’s objectives, and the results are clearly presented. However, I would like to offer a few specific comments:

QUESTION: Table 2 appears somewhat overcrowded and may benefit from being simplified or reorganized for clarity.

ANSWER: Thank you for your comment. It is true that the table contained a large amount of information. To improve readability, we decided to split it into two parts. Additionally, totals and percentages have been included in the first row, as suggested by one of the reviewers. Please see Tables 1 and 2 on lines 174 and 179, respectively.

QUESTION: Table 5 seems out of place and may be redundant; the authors might consider omitting it or integrating its content more effectively into the text.

ANSWER: To the best of our knowledge, this table is still highly important for public health purposes and, in particular, for the transmission and prevention of STIs. So, we believe it should be kept in the paper.

QUESTION: Line 235: Could you please clarify what “blood culture units” mean? The term is ambiguous in this context.

ANSWER: The use of this inaccurate term is due to a translation issue. In the revised version of the paper, we have replaced it by “microbiology and blood testing laboratories”, the facilities where blood works are analysed.

QUESTION: Lines 248–249: You mention differences in hospital utilization based on region of origin. However, without morbidity data, the significance of this finding is unclear. For example, if UMSW from the Middle East and North Africa have higher levels of illness compared to those from South America, it would naturally follow that they use hospital services more frequently. While I understand that stratification by health status may not have been feasible, this represents a significant limitation that should be more explicitly acknowledged.

ANSWER: Thank you very much for the suggestion to clarify this limitation in our study. We have included the following paragraph in the limitations section: “In addition, the lack of morbidity data (i.e. general health status) as well cultural patters (knowledge regarding healthcare systems and their cultural appropriateness) limit the understanding of why hospital utilization varies among UMSWs from different regions”. See line 311.

QUESTION: Was the use of pre-exposure prophylaxis (PrEP) documented in the study? Is PrEP currently offered to UMSW in this setting?

ANSWER: This is a very pertinent comment. However, PrEP was implemented in Spain starting in December 2019, and the study predates its approval, using data from 2017.

QUESTION: Do you have a hypothesis or explanation for why people living with HIV (PLWH) in your cohort do not appear to utilize healthcare services more frequently than those without HIV?

ANSWER: This article identifies new HIV diagnoses, but it does not include a comparison between HIV-positive and HIV-negative cohorts, since this is not within the objectives of the study.

QUESTION: Based on your findings, could you propose strategies or recommendations to improve healthcare access and utilization among UMSW?

ANSWER: Given the lower utilization of healthcare services and the marked differences by region of origin, it is important to emphasize the promotion of visits to community-led services. Ensuring regular testing, promoting health, and preventing new infections in UMSWs could be part of the solution, as observed in studies of other STD risk groups, as noted in the Discussion section (see lines 277 to 287) and in the Conclusions (lines 335 to 347).

Reviewer 2 Report

Comments and Suggestions for Authors

General:

This is an important study looking at a significant issue in an understudied context. The authors have access to multiple administrative data sets which can provide information on a highly vulnerable population. This presents a great opportunity for exploring the health and healthcare utilization of undocumented migrant sex workers in Catalonia. However, the authors fail to take advantage of this opportunity and make a contribution to the literature. The setup of the paper is just a quick overview on a selection of topics and does not provide adequate background or justification for the paper. It is lacking context, flow, and fails to set up the justification for this study. There is no rationale for the analytic approach and the implications of the findings are almost completely lacking as well. While this study has potential, in its current form, it does not make a contribution to the literature. I would not recommend it for publication without a significant overhaul including rewriting the introduction and background; new analyses based on specific, justified, and evidence-based research questions and the distributions within the data; reformatting the results section; and rewriting the discussion. Some specific recommendations are outlined below, but given the assessment of the study, those are necessary but not sufficient to prepare this study for publication.

Writing/Editing

The paper could use another round of close editing for grammar and flow. For example, there are incomplete sentences in the abstract and other sentences are missing words. Certain sections were not written out and instead are in bullet point form. The writing is fully understandable, but there are grammatical errors and some issues with flow throughout.

Abstract:

It would be good to include some more specifics regarding the results in the abstract

Introduction and Background Sections

This section needs significant work in terms of setting up the focus of the paper. It is great that it includes the global perspective and some specifics on local policy, but in trying to cover many diverse topics it doesn’t provide adequate background in several areas. It jumps around a lot from one topic to the next and provides an unnecessary level of detail on some topics and almost none on others. For example, it mentions human trafficking once, “…more specifically with regard to the issue that concerns us here, plans for the eradication of human trafficking,” but provides no additional information on human trafficking which is a different (albeit often related) topic to sex work and undocumented migrants. Another example is the first sentence of the paper. That sentence homes in on transgender, male and female sex workers, but the focus of the paper is on undocumented sex workers and the data do not include any information on the gender identity of the sex workers. These are just two examples of issues in terms of focus. The section overall should be rewritten with each paragraph introducing a relevant area of focus for the paper and providing sufficient background and citations.
The introduction does not provide sufficient background on migrants, health of sex workers or healthcare services.

Methods

This section seems to overuse bullet point structure instead of paragraphs. I would suggest that certain subsections be converted to paragraph form.
Table 1 seems more appropriate for the appendix
This relates to my comments on the introduction and background section, but the justification for the selection of variables, particularly outcome variables is lacking.
More information about the sample is needed in this section. Some of this could also go in the introduction/background section. For example, what proportion of UMSWs are eligible to apply for the public healthcare card (e.g. are in regular contact with an NGO participating in the Functional Plan)? Of those eligible, how many/what proportion apply? How many are approved and receive the card? Are the public healthcare program participation rates of UMSWs different from other undocumented migrants? Other sex workers?
1. Some of these comparisons are in the discussion section which is helpful. More information is needed in the intro and background to set up these comparisons.
The construction of the SES variable isn’t totally clear.

Results

Table 2 is somewhat difficult to read. Could it be made into landscape so it fits better and it is easier to compare across regions? I would also suggest adding a row at the bottom with the total so we can see regional totals.
Line 175: “Nine hundred and fifty-seven (57.3%) women and men contacted one or more primary care services, or emergency services during their first year in Catalonia…” This appears to be the first time that length of stay in Catalonia is brought up. How does the data indicate their arrival in Catalonia? Why is the study limited to people in their first year of arrival? This needs to be discussed further in the intro and methods section.
Line 183: “Acute hospitalization, outpatient mental healthcare services, psychiatric services, and long-term care services were not used.” This is an interesting and surprising result. Out of almost 1000 people (953) using healthcare and 808 emergency visits, there was not even one acute hospitalization?
Table 4 is very difficult to read because of formatting issues. The column width and other issues need to fixed to improve readability.
Throughout the paper, when writing out numbers, in some places periods (“.”) are used and in other places, commas (“,”) are used (e.g Table 4. 0,0555 vs. 0.0529).
This relates to multiple comments above, particularly the introduction and background, but also the methodological approach. What is the reasoning and justification for the region of origin comparisons across all outcomes? What is the theoretical, policy, and/or evidence-based rationale for this approach to analysis? What were the hypotheses for differences across regions and are these reflected in the results? This is particularly important given the distribution across regions and that all analyses include North America that has 1 person. This important background and justification information doesn’t belong in the results section, but it is necessary in order for the readers to understand why certain results are being presented.

Discussion:

Related to the comment above on the regional comparisons: These are briefly restated in the discussion section but there is no additional context provided and the implications are not mentioned. Why do differences across region of origin matter? Are there any policy implications? What does this mean for the health sector? Sex workers? Etc.

Comments on the Quality of English Language

The paper could use another round of close editing for grammar and flow. For example, there are incomplete sentences in the abstract and other sentences are missing words. Certain sections were not written out and instead are in bullet point form. The writing is fully understandable, but there are grammatical errors and some issues with flow throughout.

Author Response

Reviewer 2

QUESTION: The paper could use another round of close editing for grammar and flow. For example, there are incomplete sentences in the abstract and other sentences are missing words. Certain sections were not written out and instead are in bullet point form. The writing is fully understandable, but there are grammatical errors and some issues with flow throughout.

ANSWER: We apologise for the grammar mistakes done. Indeed, in the provided abstract the sentence "Descriptive observational study." is incomplete. It lacks a subject and verb, which are necessary to form a complete sentence. A complete version might read: "This study utilized a descriptive observational research design." See page 1 line 14.

Actually, we have revised all the text once more, and corrected all the errors that we could identify.

QUESTION: It would be good to include some more specifics regarding the results in the abstract.

ANSWER: As suggested by the reviewer, we added more a few sentences in the abstract regarding the results of the study. “Out of 1,464 women and 199 men SWs, 855 (51.4%) contacted once or more primary care services, and 378 (22.7%) used emergency services. Differences between men and women were only found regarding specific primary care services. Differences between regions of origin were found in the use of primary care services (Sub-Saharan Africa had 65.9% while Europe and Central Asia = 43.0%).” See page 1 line 17.

QUESTION: Introduction and Background Sections. This section needs significant work in terms of setting up the focus of the paper. It is great that it includes the global perspective and some specifics on local policy, but in trying to cover many diverse topics it doesn’t provide adequate background in several areas. It jumps around a lot from one topic to the next and provides an unnecessary level of detail on some topics and almost none on others.

For example, it mentions human trafficking once, “…more specifically with regard to the issue that concerns us here, plans for the eradication of human trafficking,” but provides no additional information on human trafficking which is a different (albeit often related) topic to sex work and undocumented migrants.

Another example is the first sentence of the paper. That sentence homes in on transgender, male and female sex workers, but the focus of the paper is on undocumented sex workers and the data do not include any information on the gender identity of the sex workers. These are just two examples of issues in terms of focus. The section overall should be rewritten with each paragraph introducing a relevant area of focus for the paper and providing sufficient background and citations.

ANSWER: Thank you very much for the observation. We fully agree that highlighting human trafficking for the purpose of sex work is not addressed in this article and could lead to confusion. For this reason, the sentence has been removed from the text (see page 1, line 33). It is also true that, although we cannot stratify by gender in our article due to incomplete recording in the information system, we believe it is important to describe this aspect in the introduction. Based on our knowledge, there is significant gender diversity among sex workers in our setting.

QUESTION: The introduction does not provide sufficient background on migrants, health of sex workers or healthcare services.

ANSWER: Thank you for the observation. We have expanded the information by adding the following text “and experience limited healthcare access globally, with stark regional disparities. In Mexico City, 77.7% of male sex workers had ever tested for HIV, despite a 38% HIV prevalence. In India, outreach programs have achieved 70% consistent condom use among female sex workers, while in sub-Saharan Africa, fewer than 50% report regu-lar access to STI screening. In Eastern Europe, structural stigma and criminalization result in even lower service use, with coverage of HIV prevention programs falling be-low 30% in some countries”. See page 1 line 27.

QUESTION: Methods. This section seems to overuse bullet point structure instead of paragraphs. I would suggest that certain subsections be converted to paragraph form.

ANSWER: We prefer to keep the bullet point structure, since it improves readability.

QUESTION: Table 1 seems more appropriate for the appendix.

ANSWER: Following the reviewer suggestion, Table 1 has been placed on an appendix. Thank you very much for your suggestion.

QUESTION: This relates to my comments on the introduction and background section, but the justification for the selection of variables, particularly outcome variables is lacking.

ANSWER: The selected variables are those available in the information systems of the Catalan Department of Health, and related to the type of visit and STI testing. It is true that variables related to pathologies or comorbidities were not considered, as they were not within the scope of the study.

QUESTION: More information about the sample is needed in this section. Some of this could also go in the introduction/background section. For example, what proportion of UMSWs are eligible to apply for the public healthcare card (e.g. are in regular contact with an NGO participating in the Functional Plan)? Of those eligible, how many/what proportion apply? How many are approved and receive the card? Are the public healthcare program participation rates of UMSWs different from other undocumented migrants? Other sex workers?

ANSWER: Unfortunately, and although highly informative, this information is not available.

QUESTION: Some of these comparisons are in the discussion section, which is helpful. More information is needed in the intro and background to set up these comparisons.

ANSWER: Following the reviewer suggestion, we have included in the introduction section information on healthcare service utilization and STI prevalences in other settings, in order to allow for comparison as much as possible, as also requested by another reviewer. See page 1 line 27.

QUESTION: The construction of the SES variable isn’t totally clear.

ANSWER: Together with the co-authors, and after consulting with the data managers, we decided to eliminate the SES variable. Under the current SES classification system, undocumented migrants are automatically assigned to a fictitious category solely with the aim of granting them acces to the healthcare system. Therefore, any analysis using this variable might be flawed and may lead to misleading conclusions. See table 1, table 2, page 4 from line 135 to 140, page 5 line 170 and page 16 from line 309 to 315.

QUESTION: Table 2 is somewhat difficult to read. Could it be made into landscape so it fits better and it is easier to compare across regions? I would also suggest adding a row at the bottom with the total so we can see regional totals.

ANSWER: We totally agree. We have split the table to make it more manageable—first, a table with the total, followed by another one broken down by region of origin (see Tables 1 and 2). Additionally, totals and percentages have been included in the first row.

QUESTION: Line 175: “Nine hundred and fifty-seven (57.3%) women and men contacted one or more primary care services, or emergency services during their first year in Catalonia…” This appears to be the first time that length of stay in Catalonia is brought up. How does the data indicate their arrival in Catalonia? Why is the study limited to people in their first year of arrival? This needs to be discussed further in the intro and methods section.

ANSWER : We apologise if the sentence was misleading. We have reworded the text as follows: “first year since they obtained the health card in Catalonia”. See page 7 line 183 and page 16 line 304. Actually, we have used the official denomination “health card” in the revised version of the text.

QUESTION: Line 183: “Acute hospitalization, outpatient mental healthcare services, psychiatric services, and long-term care services were not used.” This is an interesting and surprising result. Out of almost 1000 people (953) using healthcare and 808 emergency visits, there was not even one acute hospitalization?

ANSWER: We have reviewed the data, and indeed, there are no acute hospitalizations.

QUESTION: Table 4 is very difficult to read because of formatting issues. The column width and other issues need to fixed to improve readability.

ANSWER: We completely agree. We have modified the table and placed it in landscape orientation to improve readability. Thank you very much for the suggestion (see Table 4)

QUESTION: Throughout the paper, when writing out numbers, in some places periods (“.”) are used and in other places, commas (“,”) are used (e.g Table 4. 0,0555 vs. 0.0529).

ANSWER: We have revised all the text and made all changes needed.

QUESTION: This relates to multiple comments above, particularly the introduction and background, but also the methodological approach. What is the reasoning and justification for the region of origin comparisons across all outcomes? What is the theoretical, policy, and/or evidence-based rationale for this approach to analysis? What were the hypotheses for differences across regions and are these reflected in the results? This is particularly important given the distribution across regions and that all analyses include North America that has 1 person. This important background and justification information doesn’t belong in the results section, but it is necessary in order for the readers to understand why certain results are being presented.

ANSWER: The reasoning and justification for comparing the region of origin across all outcomes is based in understanding the diverse socio-cultural, economic, and health dynamics that can influence healthcare access and usage among undocumented migrant sex workers (UMSWs). This approach provides insights into the structural and systemic barriers faced by migrants from different backgrounds, which are critical for designing effective and equitable healthcare policies.

The theoretical rationale is based on the acknowledgment that migrants from different regions bring distinct cultural norms, languages, and experiences that shape their interaction with healthcare systems. This includes differences in health-seeking behaviours, awareness of healthcare services, and even perceived stigma or discrimination in healthcare settings, which can significantly impact their use of these services.

From a policy perspective, identifying these differences is vital to tailor healthcare interventions to specific needs and challenges faced by these populations, ensuring that strategies are both culturally sensitive and effectively address the barriers unique to each group.

Evidence-based rationale comes from previous studies indicating significant disparities in healthcare access and outcomes among migrant populations based on regional and ethnic backgrounds. These disparities highlight the need for targeted policy action to mitigate inequalities and enhance healthcare equity and accessibility. We have also expanded the information by adding the following text at introduction section “and experience limited healthcare access globally, with stark regional disparities. In Mexico City, 77.7% of male sex workers had ever tested for HIV, despite a 38% HIV prevalence. In India, outreach programs have achieved 70% consistent condom use among female sex workers, while in sub-Saharan Africa, fewer than 50% report regu-lar access to STI screening. In Eastern Europe, structural stigma and criminalization result in even lower service use, with coverage of HIV prevention programs falling be-low 30% in some countries”. See page 1 line 27.

The inclusion of North America, despite the small sample size, was done to maintain a comprehensive approach that considers all geographic regions where UMSWs may originate. While the presence of a single participant limits the statistical power and representativeness for North America, including this region allows us to identify potential trends and ensure that any unique narrative or outlier data isn’t overlooked in the comprehensive review.

QUESTION: Discussion: Related to the comment above on the regional comparisons: These are briefly restated in the discussion section but there is no additional context provided and the implications are not mentioned. Why do differences across region of origin matter? Are there any policy implications? What does this mean for the health sector? Sex workers? Etc.

ANSWER: In our results, these hypotheses are reflected in the observed differences in healthcare usage and health outcomes among UMSWs from different regions, providing empirical support for the theoretical and policy rationale behind this comparative approach. This reinforces the importance of context-specific interventions aimed at reducing healthcare inequalities among migrant populations. This has been included in conclusions. See page 16 line 328.

QUESTION: Comments on the Quality of English Language. The paper could use another round of close editing for grammar and flow. For example, there are incomplete sentences in the abstract and other sentences are missing words. Certain sections were not written out and instead are in bullet point form. The writing is fully understandable, but there are grammatical errors and some issues with flow throughout.

ANSWER: We have revised all the text once more, and corrected the errors that we could identify.

Reviewer 3 Report

Comments and Suggestions for Authors

This study cannot be generalized to the universe of UMSWs because the sample is limited to those who applied for public healthcare cards. Yet, there is no discussion in the paper about this sampling bias and its implications for interpreting the results. This is a serious flaw in the paper. The authors have more insight than the readers about this limitation so it is their responsibility to describe and discuss it, even if it involves speculation on their part.

In lines 131 and 132, the income brackets are too wide for very much meaningful social scientific utility at all. No explanation for this appears until the Discussion section, lines 288-291. Seeing those income brackets without any explanation of them adjacent to their first appearance leads the reader to discount the quality of the researchers' efforts prematurely. (And after the sampling bias, mentioned above, some readers would view this article as fatally flawed even though it does address an important public health issue amongst an under-researched population.)

Throughout the results section the sample size is insufficient for all the intersections of demographic variables provided. There should be at least 25 and preferably 30 cases per cell. The only way to achieve that is to combine categories. If that is not a suitable way to handle that problem for the authors the alternative would be to insert dashes in the cells where the Ns are too small for meaningful interpretation. This occurs in Tables 2 and 4.

Table 4 is mostly unreadable due to careless formatting. Because this is where most of the findings are located, the authors present an unacceptable situation.

Comments on the Quality of English Language

Sentences must have a subject, a verb, and an object: "Descriptive observational study." is NOT a sentence. Even if the clause, "This is a" seems needlessly wordy it is grammatically necessary. The same issue is present elsewhere (e.g., line 75).

Although the acronym, UMSW, is defined appropriately in the abstract, the definition needs to be repeated for the first instance of the acronym in the main text (line 66).

In line 102, is "Primary care clinical station" supposed to be plural? The compound noun needs either to be preceded by the definite article, "The"; or it needs to be made plural by making "station" plural: "stations."

In lines 108 and 112, the verb "attended" needs an object. They attended, or were attended by, what. The meaning is not at all clear.

I notice in Table 5 that the European way of expressing decimals (using a comma) is mixed up with the Anglophone way (using a point). The authors must at least pick one of the two ways and stick with it consistently.

Author Response

Reviewer 3

QUESTION: This study cannot be generalized to the universe of UMSWs because the sample is limited to those who applied for public healthcare cards. Yet, there is no discussion in the paper about this sampling bias and its implications for interpreting the results. This is a serious flaw in the paper. The authors have more insight than the readers about this limitation so it is their responsibility to describe and discuss it, even if it involves speculation on their part.

ANSWER: We have added a sentence that better reflects the identified limitation: “Further, the utilization of health services as well as the prevalence and incidence rates of STDs may present an estimation bias, since not all UMSWs contacted the public healthcare system. Possibly, then, the data may not be generalizable to the entire population of UMSWs.” See page 16 line 307.

QUESTION: In lines 131 and 132, the income brackets are too wide for very much meaningful social scientific utility at all. No explanation for this appears until the Discussion section, lines 288-291. Seeing those income brackets without any explanation of them adjacent to their first appearance leads the reader to discount the quality of the researchers' efforts prematurely. (And after the sampling bias, mentioned above, some readers would view this article as fatally flawed even though it does address an important public health issue amongst an under-researched population.)

ANSWER: Together with the co-authors, and after consulting with the data managers, we decided to eliminate the SES variable. Under the current SES classification system, undocumented migrants are automatically assigned to a fictitious category solely with the aim of granting them access to the healthcare system. Therefore, any analysis using this variable might lead to misleading conclusions.

QUESTION: Throughout the results section the sample size is insufficient for all the intersections of demographic variables provided. There should be at least 25 and preferably 30 cases per cell. The only way to achieve that is to combine categories. If that is not a suitable way to handle that problem for the authors the alternative would be to insert dashes in the cells where the Ns are too small for meaningful interpretation. This occurs in Tables 2 and 4.

ANSWER: We believe it is important to include the STI table even if there are few or no reported cases, as it is a relevant aspect of public health. Furthermore, it highlights in the same article that we have been able to investigate all of them. In Tables 2 and 4, the asterisks (“*”) appear in the interquartile range when the number of cases is 0.

QUESTION: Table 4 is mostly unreadable due to careless formatting. Because this is where most of the findings are located, the authors present an unacceptable situation.

ANSWER: Tables were formatted following the journal specifications. However, our table is too big. So, we modified the table and reformatted it in landscape orientation to improve readability. Thank you very much. (see Table 4)

QUESTION: Comments on the Quality of English Language. Sentences must have a subject, a verb, and an object: "Descriptive observational study." is NOT a sentence. Even if the clause, "This is a" seems needlessly wordy it is grammatically necessary. The same issue is present elsewhere (e.g., line 75).

ANSWER: We have revised all the text once more, and corrected the errors that we could identify.

QUESTION: Although the acronym, UMSW, is defined appropriately in the abstract, the definition needs to be repeated for the first instance of the acronym in the main text (line 66).

ANSWER: You are totally right. We have repeated the definition in the main text. See page 2, line 74.

QUESTION: In line 102, is "Primary care clinical station" supposed to be plural? The compound noun needs either to be preceded by the definite article, "The"; or it needs to be made plural by making "station" plural: "stations."

ANSWER: We have reworded the text, using “Primary care electronic clinical history program (eCAP)” instead of “Primary care clinical station".

QUESTION: In lines 108 and 112, the verb "attended" needs an object. They attended, or were attended by, what. The meaning is not at all clear.

ANSWER: We have corrected the error. Actually, we revised all the text once more, and corrected the errors that we could identify.

QUESTION: I notice in Table 5 that the European way of expressing decimals (using a comma) is mixed up with the Anglophone way (using a point). The authors must at least pick one of the two ways and stick with it consistently.

ANSWER: Thank you very much for the warning and observation. We have already made the change; see Table 5.