Urban Environmental Determinants and Spatiotemporal Patterns of Emergency Medical Service Response to Traumatic Injuries: A Five-Year Population-Based Study

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study presents a retrospective analysis of 26,073 trauma-related EMS calls in Astana (2020–2024), integrating demographic, temporal, and GIS-based spatial methods. The authors conclude that proximity-based EMS deployment and infrastructure optimization are necessary to improve urban health equity. The identification of peak demand periods, geographic disparities, and system bottlenecks is particularly relevant for policymakers.

Major Suggestions:

1. Consider strengthening the analytical approach by incorporating multivariable analysis to better identify determinants of prolonged EMS response times. This would enhance the explanatory power beyond descriptive findings.
2. Relevant studies from other countries and healthcare systems should be incorporated, particularly to contextualize findings and enable comparison. This should be expanded in both the Introduction and Discussion sections.
3. In Section 4.1., the distinction between clinically appropriate and inappropriate hospitalization refusals is introduced but not previously defined or quantitatively examined. Providing a clear definition and, if possible, a breakdown or analysis of these categories would substantially strengthen this argument.
4. The discussion on spatial inequity (Section 4.3.) is a strong component of the manuscript that could stimulate policy discussions. To further enhance its impact, consider citing comparable studies that report similar spatial disparities in EMS response times and explicitly comparing your findings with existing evidence.

Minor Suggestions:

1. The study appears to be registry-based, which raises concerns regarding the accuracy of the informed consent statement. The claim that “informed consent was obtained electronically from all participants” should be clarified or revised to ensure consistency with the retrospective design.
2. Include a missing data analysis to allow readers to assess the extent and potential impact of bias in the dataset.
3. Provide a data processing or cleaning flowchart outlining the transition from the raw dataset to the final analytical sample of 26,073 records. This would improve transparency and reproducibility.
4. Align with STROBE reporting guidelines for observational studies.

Overall, this is a well-conceived and methodologically promising study that addresses an important gap in EMS research within Central Asia.

Comments on the Quality of English Language

Well-written.

Author Response

Major suggestions:

1. Consider strengthening the analytical approach by incorporating multivariable analysis to better identify determinants of prolonged EMS response times. This would enhance the explanatory power beyond descriptive findings.

Authors' responses: Thank you for this constructive suggestion. In response, we incorporated a multivariable logistic regression analysis to identify independent determinants of prolonged EMS response time, defined as call-to-arrival >10 minutes. The model adjusted for sex, age group, urgency category, year, season, time of day, weekend status. The analysis demonstrated that prolonged response time was independently associated with urgency level, afternoon/evening call periods, age, sex. This addition substantially strengthens the explanatory power of the study by moving beyond descriptive comparisons and isolating factors independently associated with delayed EMS arrival. Adjusted effect estimates were incorporated into the Methods, Results, and Discussion sections.

Point 2.3 of the methods section.

In Results section: Table 4.

In Discussion: in 4.2. The Diurnal Paradox and Safety Culture fourth paragraph

2. Relevant studies from other countries and healthcare systems should be incorporated, particularly to contextualize findings and enable comparison. This should be expanded in both the Introduction and Discussion sections.

Authors' responses: We thank the reviewer for this suggestion. We have expanded both the Introduction and Discussion to incorporate comparative evidence from other countries and healthcare systems. Specifically, we added studies from Sweden, the United States, China, as well as an international systematic review, to contextualize our findings on EMS delay, urban–suburban inequity, traffic-sensitive accessibility, and the role of resource distribution. These revisions strengthen the manuscript by showing that the Astana findings are consistent with broader international evidence while also highlighting the specific relevance of these issues to a rapidly expanding Central Asian capital.

Added in Intro, Discussion.

3. In Section 4.1., the distinction between clinically appropriate and inappropriate hospitalization refusals is introduced but not previously defined or quantitatively examined. Providing a clear definition and, if possible, a breakdown or analysis of these categories would substantially strengthen this argument.

Authors' responses: Thank you for this important comment. We agree that the term Refusal of Hospitalization required clearer operational definition. In the revised manuscript, we now define this category explicitly in the Methods as trauma-related EMS encounters in which the patient was assessed on scene but was not transported for inpatient hospital care, according to the disposition field recorded in the EMS registry. Because the database did not contain a validated variable allowing differentiation between clinically appropriate refusal, inappropriate refusal, patient-initiated refusal, or protocol-directed non-conveyance, we did not further subclassify these cases.

Point 2.1 of the methods section.

4. The discussion on spatial inequity (Section 4.3.) is a strong component of the manuscript that could stimulate policy discussions. To further enhance its impact, consider citing comparable studies that report similar spatial disparities in EMS response times and explicitly comparing your findings with existing evidence.

Authors' responses: Thank you for this valuable suggestion. We agree that the policy relevance of Section 4.3 is strengthened when the Astana findings are explicitly situated within the international literature. In the revised Discussion, we incorporated comparable studies from other metropolitan settings that reported spatial disparities in EMS accessibility and response time, including Busan (South Korea), Shanghai (China), and Beijing (China). We now explicitly compare our findings with these studies and highlight a shared pattern across systems: overall citywide coverage may appear acceptable, while peripheral or suburban districts experience systematically longer response times because of traffic exposure, unequal station distribution, and urban form. This revision strengthens the interpretation of the Baikonur and Saryarka findings as part of a broader and policy-relevant pattern of spatial inequity in prehospital care.

The second paragraph in discussion 4.3.

Minor suggestions:

1. The study appears to be registry-based, which raises concerns regarding the accuracy of the informed consent statement. The claim that “informed consent was obtained electronically from all participants” should be clarified or revised to ensure consistency with the retrospective design.

Authors' responses: Thank you for this important observation. We agree that the original informed consent statement was inconsistent with the retrospective registry-based design of the study. The manuscript has been revised accordingly. Specifically, we clarified that this research was based on anonymized retrospective EMS registry data and that the requirement for individual informed consent was waived by the Local Ethics Committee. We removed the incorrect statement indicating that electronic informed consent had been obtained from all participants.

Informed Consent Statement section.

2. Include a missing data analysis to allow readers to assess the extent and potential impact of bias in the dataset.

Authors' responses: Thank you for this important suggestion. We agree that the original manuscript did not sufficiently report the extent of missing data. In the revised version, we added a formal missing-data assessment to the Methods section. Before analysis, the registry extract was screened for duplicate call records and item-level missingness across demographic, temporal, outcome, and geospatial variables. Blank fields were treated as missing values.

2.3. Data Quality Assessment and Missing Data in method section.

3. Provide a data processing or cleaning flowchart outlining the transition from the raw dataset to the final analytical sample of 26,073 records. This would improve transparency and reproducibility.

Authors' responses: Thank you for this valuable suggestion. We agree that the original manuscript did not sufficiently describe the transition from the raw EMS registry extract to the final analytical cohort. In the revised version, we added a data processing and cleaning flowchart that outlines each step of sample derivation, including extraction from the source registry, trauma-case filtering, removal of duplicate records, exclusion of records with invalid or missing key timestamps, exclusion of records with insufficient address information for geocoding, and derivation of the final analytical sample of 26,073 trauma-related EMS encounters.

Figure 1 in method section.

4. Align with STROBE reporting guidelines for observational studies.

Authors' responses: We thank the reviewer for this suggestion. The manuscript has been revised to improve compliance with the STROBE reporting guideline for observational studies.

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for the opportunity to review this interesting article. I carefully read this paper. I had the following concern about the manuscript.

Major

1 Time intervals summarised in Table 2 are much longer than those reported in Europe and other advanced countries. Particularly, the call-dispatch interval is very long. Please provide details on EMS in your country.  How is EMS activated? Do you have a centralised dispatch centre? What is the cause of the delay in dispatch?

#2 Please provide the severity levels or scores of patients admitted to hospitals.

#3 Please discuss the human factors associated with the delays in hospital admission.

#4 Do you have any educational system for EMS?

 

Author Response

#1. Time intervals summarised in Table 2 are much longer than those reported in Europe and other advanced countries. Particularly, the call-dispatch interval is very long. Please provide details on EMS in your country.  How is EMS activated? Do you have a centralised dispatch centre? What is the cause of the delay in dispatch?

Authors' responses: Thank you for this important comment. We agree that the time-interval findings require clearer health-system context. In the revised manuscript, we added a description of how EMS is activated and organized in Kazakhstan. Specifically, ambulance care is accessed through the national ambulance number 103 and can also be reached through the unified emergency number 112, with medical emergencies routed to ambulance dispatch. Kazakhstan operates a centralized EMS model in which ambulance stations work through dispatch centers that receive calls, verify the address, assign urgency category, provide telephone instructions if needed, and allocate the responding team. We also clarified that the call-to-dispatch interval in our study is not simply ring-to-answer time; rather, it reflects the full dispatcher processing period from call receipt to team assignment. This includes call interrogation, triage, address clarification, and, for lower-acuity cases, possible routing to primary-health-care emergency teams. National rules set a 5-minute target for this dispatcher processing stage, and our mean value of 6.29 min therefore indicates performance above the target. However, the registry does not contain dispatcher-level reason codes, so we cannot attribute this delay to a single cause. Kazakhstan emergency contacts and EMS activation pathways are described by official government sources, while the centralized structure and 5-minute dispatcher processing standard are described in national EMS rules and contemporary publications on Kazakhstan’s ambulance system.

2.2. EMS Activation and Dispatch Context in Kazakhstan in method section.

#2 Please provide the severity levels or scores of patients admitted to hospitals.

Authors' responses: Thank you for this important comment. We agree that clinical severity should be reported more explicitly. However, the EMS registry used in this retrospective study did not contain validated trauma severity scores

#3 Please discuss the human factors associated with the delays in hospital admission.

Authors' responses: Thank you for this important comment. We agree that the original Discussion focused predominantly on spatial and traffic-related determinants and did not sufficiently address the human factors that may contribute to delay in hospital admission. In the revised manuscript, we added a paragraph discussing the likely human and organizational contributors to prolonged call-to-admission time. Specifically, we now note that this interval may be influenced by on-scene clinical assessment and stabilization, destination decision-making, communication between EMS and hospital staff, ambulance-to-ED handover quality, emergency department crowding and offload delay, and patient- or family-related factors affecting transport acceptance. Because the registry did not contain timestamps for handover completion, bed assignment, or hospital acceptance decisions, these mechanisms could not be measured directly in the present study and are therefore discussed as plausible explanatory factors rather than tested determinants.

The second paragraph in discussion.

#4 Do you have any educational system for EMS?

Authors' responses: Thank you for this relevant question. Yes, Kazakhstan does have a formal educational and training framework for emergency medical services personnel, including sector-level training activities coordinated through the National Coordination Center for Emergency Medicine and its Educational and Training Center. Officially, this center provides simulation-based and continuing training in emergency care, including ambulance dispatch, triage, BLS, ACLS, PALS, and PHTLS. However, we have not expanded this issue in the manuscript because it is beyond the direct scope of the present registry-based analysis and our dataset did not contain personnel-level variables on training, certification, or continuing professional education. Therefore, we believe that a detailed discussion of the EMS educational system, although important in general, would be descriptive rather than analytically supported in the context of the current study.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for your good revision of the manuscript. I have no further comments.