Review Reports - Medication Adherence in Adults with Type 2 Diabetes Mellitus Across Gulf Cooperation Council Countries: A Scoping Review of Determinants, Measurement Approaches, and Intervention Evidence

Round 1

Reviewer 1 Report (New Reviewer)

Comments and Suggestions for Authors

Overall, it is well written and addresses an important and timely topic. The focus on medication adherence among patients with T2DM in GCC countries is relevant and valuable.

I have one main suggestion to strengthen the abstract:

Include the number of studies and the total number of participants, for example, “Of 3,457 records screened, 78 studies met the inclusion criteria,” along with the total number of participants and, if available, the male/female distribution. This information would provide readers with a clearer understanding of the scope of the evidence.

Table: Add a sample characteristics column to the table (Supplementary Table S2. Summary of Evidence on Determinants and Interventions Affecting Medication Adherence in Type 2 Diabetes Patients Across Gulf).

Minor edits:

Line 366: A study from Indonesia (a Muslim-majority country) found that adherence significantly declined during Ramadan because of changes in meal times, increased busyness, and a lack of guidance on adjusting medication schedules.

Lines 662-677: The present review identified several knowledge gaps. To begin with, evidence varies by country: Saudi Arabia and the UAE have several recent studies, but evidence from Kuwait and Bahrain is scarce and, in most cases, qualitative or based on older samples. Second, most studies use self-reported adherence instruments (e.g., MMAS-8, GMAS, or author-developed tools), which have several limitations, including recall and social desirability bias; objective measures, such as pharmacy refill records, electronic monitoring, or biomarker-based proxies, are rarely used. Third, longitudinal studies are rare, and most studies are cross-sectional, making it difficult to infer causal relationships between associated factors, adherence behavior, and clinical outcomes. Fourth, there is limited evidence on at-risk subgroups, including seniors, rural populations, migrants, and patients with multimorbidity. In addition, although cultural and religious factors (e.g., Ramadan fasting, family dynamics) are often mentioned, few studies formally measure their effect on adherence or test culturally tailored interventions. Finally, Recent Saudi and Omani validation studies broaden the measurement base but also introduce ASMA and MAUQ constructs that are not directly interchangeable with MMAS, GMAS, ARMS, MARS, or PDC.

Thank you.

Author Response

Authors’ reply/modifications according to the reviewer 1 comments/suggestions

General:

The authors would like to thank the reviewer for the precious time spent reviewing the paper and his excellent suggestions for improving it. Efforts have been made to modify the paper as per the reviewer’s suggestions and recommendations. The authors will be happy to hear a positive reply. All the points included according to the reviewer’s comments can be seen in track changes.

Specific response to the reviewer’s suggestions:

Kindly find the attached response to each question one by one:

Overall comment: Overall, it is well written and addresses an important and timely topic. The focus on medication adherence among patients with T2DM in GCC countries is relevant and valuable.

Authors’ Response: Thank you very much for your positive and encouraging comment. We appreciate the reviewer’s recognition of the relevance and value of this topic.

Point 1: I have one main suggestion to strengthen the abstract: Include the number of studies and the total number of participants, for example, “Of 3,457 records screened, 78 studies met the inclusion criteria,” along with the total number of participants and, if available, the male/female distribution. This information would provide readers with a clearer understanding of the scope of the evidence.

Response 1: Thank you for this helpful suggestion. We have revised the Abstract to clarify the scope of the evidence by reporting that 3,457 records were screened, 549 reports were assessed for eligibility, and 78 studies met the inclusion criteria. A pooled sample size and sex distribution were not included because these data were not consistently available across the included studies.

Point 2: Table: Add a sample characteristics column to the table (Supplementary Table S2. Summary of Evidence on Determinants and Interventions Affecting Medication Adherence in Type 2 Diabetes Patients Across Gulf).

Response 2: Thank you for this helpful suggestion. We have revised Supplementary Table S2 by adding a “Sample characteristics” column, including available information on sample size and relevant participant characteristics for each study.

Point 3: Minor edits:

Response 3: Thanks for the comment. The suggested minor grammatical correction has been made.

Point 4: Lines 662-677: The present review identified several knowledge gaps. To begin with, evidence varies by country: Saudi Arabia and the UAE have several recent studies, but evidence from Kuwait and Bahrain is scarce and, in most cases, qualitative or based on older samples. Second, most studies use self-reported adherence instruments (e.g., MMAS-8, GMAS, or author-developed tools), which have several limitations, including recall and social desirability bias; objective measures, such as pharmacy refill records, electronic monitoring, or biomarker-based proxies, are rarely used. Third, longitudinal studies are rare, and most studies are cross-sectional, making it difficult to infer causal relationships between associated factors, adherence behavior, and clinical outcomes. Fourth, there is limited evidence on at-risk subgroups, including seniors, rural populations, migrants, and patients with multimorbidity. In addition, although cultural and religious factors (e.g., Ramadan fasting, family dynamics) are often mentioned, few studies formally measure their effect on adherence or test culturally tailored interventions. Finally, Recent Saudi and Omani validation studies broaden the measurement base but also introduce ASMA and MAUQ constructs that are not directly interchangeable with MMAS, GMAS, ARMS, MARS, or PDC.

Response 4: Thank you for this helpful suggestion. The paragraph has been revised accordingly to improve clarity and readability.

The authors thank the reviewer again for the positive and constructive comments.

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

Overall Assessment

This manuscript addresses an important and clinically relevant topic: medication adherence among adults with type 2 diabetes mellitus across the Gulf Cooperation Council (GCC) countries. The topic is particularly relevant given the substantial burden of diabetes in the region and the potential impact of medication adherence on long-term disease management.

The manuscript has several strengths, including its regional focus, broad coverage of adherence determinants and measurement approaches, inclusion of both quantitative and qualitative evidence, and consideration of emerging digital and pharmacist-led interventions. The authors also appropriately acknowledge substantial heterogeneity in adherence measurement instruments, study populations, and settings.

However, several methodological, reporting, and interpretive issues should be addressed before the manuscript can be considered for publication. In particular, greater transparency is needed regarding the search process and study selection, while the synthesis should more clearly distinguish medication-adherence outcomes from glycaemic or clinical outcomes. The intervention section also requires substantial clarification regarding the nature and strength of the available evidence.

I therefore recommend Major Revision.

Major Comments

1. Clarify the exact search dates and the apparent publication-date inconsistency

The manuscript states that the literature search covered publications from 1 January 2020 through 31 July 2026. However, the manuscript metadata and page headers still identify the article as Healthcare 2025, and the manuscript does not clearly report the actual date on which each database was searched.

Please provide the exact search date(s) for PubMed, Scopus, Web of Science, and the Saudi Digital Library. If the searches were conducted on different dates, these should be reported separately.

The authors should also clarify whether all studies described as 2026 publications were already published online/in press and available for retrieval by the stated final search date of 31 July 2026.

This clarification is important for reproducibility and for resolving the apparent discrepancy between the stated search period and the manuscript metadata.

2. Improve reporting of the search strategy

Table 1 provides the databases, timeframe, and general search terms, but the search strategy is not sufficiently reproducible.

Please provide the complete database-specific search strings, including Boolean operators, field restrictions, truncation/wildcards where applicable, and any filters or limits used.

It would also be helpful to report:

• the exact search date for each database;

• the number of records retrieved from each database;

• whether the Saudi Digital Library search involved a specific underlying database or platform;

• whether reference-list searching identified any additional eligible studies.

The current Figure 1 reports 910 records from PubMed, 1,012 from Scopus, 782 from Web of Science, and 753 from the Saudi Digital Library, but these numbers should ideally also be documented in the methodological description or supplementary search documentation.

3. Provide a more detailed breakdown of full-text exclusions

The PRISMA flowchart reports:

3,457 records screened;

549 reports assessed for eligibility;

471 reports excluded;

78 studies included.

The arithmetic is internally consistent. However, the 471 full-text exclusions are presented only as aggregated reasons, including non-GCC/T2DM-specific studies, absence of a medication-adherence outcome, non-original research, unavailable/non-English full text, and duplicate/overlapping data.

Please provide the number of excluded reports for each full-text exclusion reason.

If these numbers were recorded in the screening database, they should be added to the PRISMA flow diagram or supplementary material. If they cannot be reconstructed reliably, this should be stated rather than assigning retrospective numbers.

4. Include the missing Supplementary Table S2

The manuscript repeatedly refers to Supplementary Table S2, described as:

“Summary of Evidence on Determinants and Interventions Affecting Medication Adherence…”

However, Table S2 is not included in the manuscript file provided for review. The manuscript explicitly identifies this table as supplementary material.

Please ensure that the complete Table S2 is submitted and accessible to reviewers.

Given that this scoping review includes 78 studies, a comprehensive evidence table is particularly important for evaluating the accuracy and completeness of the synthesis.

5. Provide a more systematic synthesis of adherence measurement instruments

Measurement heterogeneity is one of the central issues in this review. The manuscript appropriately notes the use of MMAS-8, GMAS, MARS, ARMS-12, MARS-5, SDSCA medication domains, ASMA, Omani Arabic MAUQ, and PDC, among others.

However, the manuscript would benefit substantially from a dedicated table comparing the instruments.

Please consider reporting, where available:

• instrument name;

• number of items/domains;

• type of measure (self-report vs objective);

• scoring approach;

• adherence categories/cutoffs;

• validation status;

• language/Arabic validation;

• country in which it was used;

• study population;

• whether the measure assesses medication adherence specifically or broader treatment/self-management behaviour.

This would help readers understand why reported adherence rates cannot be directly compared across studies.

6. Avoid presenting heterogeneous adherence rates as directly comparable regional estimates

The manuscript appropriately acknowledges that adherence estimates vary according to instrument, cutoff, setting, and patient characteristics.

Nevertheless, some sections use language that may lead readers to interpret these heterogeneous estimates as a coherent regional prevalence.

The authors should consistently emphasize that the reported percentages are study-specific estimates rather than pooled or directly comparable GCC prevalence estimates.

If ranges are presented, the corresponding measurement instrument and cutoff should be clearly identified.

7. Clarify the geographical distribution of the evidence

The manuscript acknowledges that Saudi Arabia and the UAE have considerably more evidence than Kuwait and Bahrain.

Please provide a clear numerical summary of the number of included studies from each GCC country.

A table or figure showing:

would substantially improve the interpretation of the evidence base.

The Discussion should also explicitly address how the substantial geographical imbalance affects the generalizability of conclusions to the GCC region as a whole.

8. Strengthen the distinction between determinants, correlates, mediators, and outcomes

This is an important conceptual issue.

The Methods section appropriately states that HbA1c and glycaemic control are generally considered outcomes rather than direct determinants of adherence unless analyzed as predictors in the original study.

However, this distinction is not consistently maintained throughout the Results and Discussion.

For example, the Discussion refers to poor glycaemic control together with factors associated with lower adherence.

The authors should systematically classify findings into:

1. Potential determinants/predictors of adherence

2. Barriers/facilitators

3. Medication-taking/adherence outcomes

4. Clinical consequences or outcomes associated with adherence, such as HbA1c

5. Potential bidirectional associations

Because many included studies are cross-sectional, causal terminology should be avoided unless supported by the study design.

9. Separate direct medication-adherence outcomes from glycaemic outcomes in the intervention synthesis

This is a particularly important issue.

Some interventions appear to have been evaluated primarily using HbA1c, fasting glucose, weight, engagement, or other clinical outcomes, rather than a validated medication-adherence outcome.

For example, the discussion of My Dose Coach emphasizes faster achievement of fasting glucose levels, while the GluCare discussion primarily reports HbA1c and weight outcomes.

Improvement in glycaemic control should not automatically be interpreted as evidence of improved medication adherence.

Please classify intervention studies according to whether they:

• directly measured medication adherence;

• measured medication possession/refill metrics;

• measured self-reported adherence;

• measured only glycaemic/clinical outcomes;

• or measured both adherence and clinical outcomes.

This distinction would substantially strengthen the scientific validity of the intervention synthesis.

10. Distinguish completed intervention studies from protocols and ongoing trials

The intervention section should clearly distinguish completed studies reporting results from study protocols or ongoing trials.

In particular, the Qatar Diabetes Mobile Application Trial (QDMAT) is cited as a study protocol, not as a completed efficacy study. The reference itself identifies it as a protocol, and its primary outcome is planned to be the six-month change in HbA1c.

Therefore, QDMAT should not be presented as evidence demonstrating intervention effectiveness or improved medication adherence.

Please revise the intervention synthesis accordingly and clearly label:

• completed intervention studies;

• ongoing trials/protocols;

• observational evaluations of interventions;

and interventions with only clinical outcomes.

11. Provide a structured table of intervention characteristics

The intervention evidence is currently presented primarily in narrative form.

Please provide a dedicated table summarizing, at minimum:

• country;

• intervention type;

• study design;

• sample size;

• intervention provider;

• intervention duration;

• comparator/control;

• adherence measurement method;

• adherence outcome;

• clinical outcome;

• reported effect size/statistical significance;

• follow-up duration.

This would allow readers to distinguish interventions with direct evidence of improved adherence from those showing improvements only in clinical outcomes.

12. Moderate the interpretation of intervention effectiveness

The manuscript appropriately acknowledges that intervention evidence is limited and heterogeneous.

However, terms such as “promising,” “powerful tool,” “supporting medication adherence,” and similar statements should be used cautiously when the evidence is based on small studies, observational designs, indirect outcomes, or heterogeneous adherence measures.

The absence of formal risk-of-bias assessment is not necessarily a methodological flaw in a scoping review. However, because the manuscript explicitly discusses intervention potential and effectiveness, the conclusions should be appropriately qualified.

I recommend either:

substantially tempering causal/effectiveness language throughout the Results, Discussion, Abstract, and Conclusions; or

if the authors consider an appraisal necessary for their intended interpretation, providing an appropriate critical appraisal of the relevant intervention evidence and explaining the chosen methodology.

13. Improve integration of qualitative evidence

The manuscript includes qualitative studies addressing issues such as insulin refusal, self-adjustment of doses, beliefs about alternative treatments, forgetfulness, physician–patient relationships, family support, and perceived barriers.

However, qualitative and quantitative evidence are not always clearly distinguished in the synthesis.

I recommend a dedicated subsection or table for qualitative evidence summarizing:

• country;

• qualitative methodology;

• participant characteristics;

• major themes;

• barriers/facilitators identified;

• and how these findings complement quantitative evidence.

This would be particularly valuable for the sociocultural component of the review.

14. Clarify the role of the term “compliance”

The search strategy includes “drug compliance” among the search terms.

This is acceptable as a search synonym because terminology varies across the literature. However, the manuscript should consistently use “medication adherence” in the narrative unless discussing terminology used by an individual source.

A brief statement explaining that “compliance” was retained only as a search synonym would improve methodological clarity.

Author Response

Authors’ reply/modifications according to the reviewer 2 comments/suggestions

General:

Specific response to the reviewer’s suggestions:

Kindly find the attached response to each question one by one:

Overall comment: This manuscript addresses an important and clinically relevant topic: medication adherence among adults with type 2 diabetes mellitus across the Gulf Cooperation Council (GCC) countries. The topic is particularly relevant given the substantial burden of diabetes in the region and the potential impact of medication adherence on long-term disease management.

Response: Thank you for this comment. Thank you for your constructive assessment and recognition of the manuscript’s strengths and clinical relevance. We appreciate the reviewer’s valuable observations. We have carefully addressed the specific comments and revised the manuscript to improve methodological transparency, clarify the distinction between medication adherence and clinical outcomes, and strengthen the interpretation of intervention evidence.

Point 1: Clarify the exact search dates and the apparent publication-date inconsistency

Please provide the exact search date(s) for PubMed, Scopus, Web of Science, and the Saudi Digital Library. If the searches were conducted on different dates, these should be reported separately.

The authors should also clarify whether all studies described as 2026 publications were already published online/in press and available for retrieval by the stated final search date of 31 July 2026.

This clarification is important for reproducibility and for resolving the apparent discrepancy between the stated search period and the manuscript metadata.

Response 1: Thank you for this valuable comment. In accordance with the reviewer’s suggestions, we have clarified the publication eligibility period (1 January 2020–31 July 2026) and the final search date (7 August 2026) in the revised manuscript. We have also corrected the 2025 template (downloaded from healthcare, MDPI) to 2026. The publication dates of the included 2026 studies were reviewed to ensure compliance with the eligibility period.

Point 2: Improve reporting of the search strategy

Table 1 provides the databases, timeframe, and general search terms, but the search strategy is not sufficiently reproducible.

Please provide the complete database-specific search strings, including Boolean operators, field restrictions, truncation/wildcards where applicable, and any filters or limits used.

It would also be helpful to report:

the exact search date for each database;

the number of records retrieved from each database;

whether the Saudi Digital Library search involved a specific underlying database or platform;

whether reference-list searching identified any additional eligible studies.

Response 2: Thank you for this valuable suggestion. In accordance with the reviewer’s recommendations, we have expanded the search methodology in the revised manuscript by specifying the final search date for all four databases (7 August 2026) and the number of records retrieved from each database. We have also added detailed database-specific search strategies, including Boolean operators, field restrictions, and applied filters, as Supplementary Table S3, and clarified the reference-list screening process.

Point 3: Provide a more detailed breakdown of full-text exclusions

The PRISMA flowchart reports:

3,457 records screened;

549 reports assessed for eligibility;

471 reports excluded;

78 studies included.

Please provide the number of excluded reports for each full-text exclusion reason.

Response 3: Thank you for this valuable suggestion. In accordance with the reviewer’s recommendation, we have revised Figure 1 (PRISMA flow diagram) to provide a detailed numerical breakdown of full-text exclusions according to the specific reasons for exclusion, thereby improving transparency in the study selection process.

Point 4: Include the missing Supplementary Table S2

The manuscript repeatedly refers to Supplementary Table S2, described as:

“Summary of Evidence on Determinants and Interventions Affecting Medication Adherence…”

However, Table S2 is not included in the manuscript file provided for review. The manuscript explicitly identifies this table as supplementary material.

Please ensure that the complete Table S2 is submitted and accessible to reviewers.

Given that this scoping review includes 78 studies, a comprehensive evidence table is particularly important for evaluating the accuracy and completeness of the synthesis.

Response 4: Thank you for this valuable comment. In accordance with the reviewer’s recommendation, we have included all supplementary tables, including the requested evidence summary table (renumbered as Supplementary Table S4), in a separate ZIP file accompanying the revised manuscript. We have also requested the Healthcare editorial team to ensure that all supplementary materials are accessible to the reviewers.

Point 5: Provide a more systematic synthesis of adherence measurement instruments

However, the manuscript would benefit substantially from a dedicated table comparing the instruments.

Please consider reporting, where available:

instrument name;
number of items/domains;
type of measure (self-report vs objective);
scoring approach;
adherence categories/cutoffs;
validation status;
language/Arabic validation;
country in which it was used;
study population;
whether the measure assesses medication adherence specifically or broader treatment/self-management behaviour.

This would help readers understand why reported adherence rates cannot be directly compared across studies.

Response 5: Thank you for this valuable suggestion. In accordance with the reviewer’s recommendation, we have added a detailed comparison of medication-adherence measurement instruments as Supplementary Table S3 and referred to it in the revised manuscript. The table summarises the instruments, number of items/domains, measurement approaches, scoring methods, adherence thresholds, validation status, Arabic-language availability, GCC countries, study populations, and scope of measurement.

Point 6: Avoid presenting heterogeneous adherence rates as directly comparable regional estimates

The manuscript appropriately acknowledges that adherence estimates vary according to instrument, cutoff, setting, and patient characteristics.

Nevertheless, some sections use language that may lead readers to interpret these heterogeneous estimates as a coherent regional prevalence.

The authors should consistently emphasize that the reported percentages are study-specific estimates rather than pooled or directly comparable GCC prevalence estimates.

If ranges are presented, the corresponding measurement instrument and cutoff should be clearly identified.

Response 6: Thank you for this valuable comment. In accordance with the reviewer’s recommendation, we have revised the Abstract, Results, and Discussion sections to consistently present medication-adherence percentages as study-specific estimates rather than pooled or directly comparable regional prevalence estimates. We have also clarified the influence of measurement instruments, adherence thresholds, and study populations on the reported findings. Additionally, Supplementary Table S3 provides a systematic comparison of adherence measurement instruments to support the interpretation of these variations.

Point : 7. Strengthen the distinction between determinants, correlates, mediators, and outcomes

This is an important conceptual issue.

However, this distinction is not consistently maintained throughout the Results and Discussion.

For example, the Discussion refers to poor glycaemic control together with factors associated with lower adherence.

The authors should systematically classify findings into:

Potential determinants/predictors of adherence
Barriers/facilitators
Medication-taking/adherence outcomes
Clinical consequences or outcomes associated with adherence, such as HbA1c
Potential bidirectional associations

Because many included studies are cross-sectional, causal terminology should be avoided unless supported by the study design.

Response 7: Thank you for this important comment. In accordance with the reviewer’s recommendation, we have revised the manuscript to distinguish adherence-related factors from clinical outcomes, including HbA1c, and clarified potentially bidirectional associations while avoiding causal interpretations of cross-sectional findings.

Point 9: Separate direct medication-adherence outcomes from glycaemic outcomes in the intervention synthesis

This is a particularly important issue.

Some interventions appear to have been evaluated primarily using HbA1c, fasting glucose, weight, engagement, or other clinical outcomes, rather than a validated medication-adherence outcome.

For example, the discussion of My Dose Coach emphasizes faster achievement of fasting glucose levels, while the GluCare discussion primarily reports HbA1c and weight outcomes.

Improvement in glycaemic control should not automatically be interpreted as evidence of improved medication adherence.

Please classify intervention studies according to whether they:

directly measured medication adherence;
measured medication possession/refill metrics;
measured self-reported adherence;
measured only glycaemic/clinical outcomes;
or measured both adherence and clinical outcomes.

This distinction would substantially strengthen the scientific validity of the intervention synthesis.

Response 9: Thank you for this important comment. In accordance with the reviewer’s recommendation, we have revised the intervention synthesis to distinguish studies measuring medication adherence directly, including self-reported and refill-based measures, from those reporting only clinical outcomes or both. We have also clarified that improvements in HbA1c, fasting glucose, or weight do not necessarily indicate improved medication adherence.

Point 10: Distinguish completed intervention studies from protocols and ongoing trials

The intervention section should clearly distinguish completed studies reporting results from study protocols or ongoing trials.

Therefore, QDMAT should not be presented as evidence demonstrating intervention effectiveness or improved medication adherence.

Please revise the intervention synthesis accordingly and clearly label:

completed intervention studies;
ongoing trials/protocols;
observational evaluations of interventions;

and interventions with only clinical outcomes.

Response 10: Thank you for this valuable comment. In accordance with the reviewer’s recommendation, we have revised the intervention section to distinguish completed studies, observational evaluations, and study protocols. We have also clarified that QDMAT is a study protocol and does not provide evidence of intervention effectiveness.

Point 11: 11. Provide a structured table of intervention characteristics

The intervention evidence is currently presented primarily in narrative form.

Please provide a dedicated table summarizing, at minimum:

country;
intervention type;
study design;
sample size;
intervention provider;
intervention duration;
comparator/control;
adherence measurement method;
adherence outcome;
clinical outcome;
reported effect size/statistical significance;
follow-up duration.

This would allow readers to distinguish interventions with direct evidence of improved adherence from those showing improvements only in clinical outcomes.

Response 11: Thank you for this valuable suggestion. In accordance with the reviewer’s recommendation, we have further refined Supplementary Table S4 (Table S2 in first submission and renumbered it to S4 after including few tables as suggetested by the reviewer) to provide a more structured summary of intervention characteristics, study designs, sample sizes, measurement approaches, and adherence and clinical outcomes, including intervention duration, comparators, and reported effects where available.

Point 12: Moderate the interpretation of intervention effectiveness

The manuscript appropriately acknowledges that intervention evidence is limited and heterogeneous.

I recommend either:

substantially tempering causal/effectiveness language throughout the Results, Discussion, Abstract, and Conclusions; or

Response 12: Thank you for this valuable comment. In accordance with the reviewer’s recommendation, we have moderated the language regarding intervention effectiveness throughout the revised manuscript and clarified the limitations of the available evidence, avoiding unsupported causal interpretations.

Point 13: Improve integration of qualitative evidence

However, qualitative and quantitative evidence are not always clearly distinguished in the synthesis.

I recommend a dedicated subsection or table for qualitative evidence summarizing:

country;
qualitative methodology;
participant characteristics;
major themes;
barriers/facilitators identified;
and how these findings complement quantitative evidence.

This would be particularly valuable for the sociocultural component of the review.

Response 13: Thank you for this valuable suggestion. In accordance with the reviewer’s recommendation, we have strengthened the qualitative evidence synthesis by explicitly highlighting the major barriers, facilitators, and sociocultural themes identified in qualitative studies and clarifying how these findings complement the quantitative evidence.

Point 14: Clarify the role of the term “compliance”

The search strategy includes “drug compliance” among the search terms.

A brief statement explaining that “compliance” was retained only as a search synonym would improve methodological clarity

Response 14: Thank you for this helpful comment. In accordance with the reviewer’s suggestion, we have clarified that “compliance” was retained as a search synonym and standardised the use of “medication adherence” throughout the revised manuscript, except when referring to terminology used in original studies.

The authors thank the reviewer once again for the positive and constructive comments.

Reviewer 3 Report (Previous Reviewer 3)

Comments and Suggestions for Authors This is a relevant and useful scoping review on medication adherence among patients with T2DM in GCC countries. It investigates the variation in adherence levels, measurement tools, associated factors, and interventions. However, a few points and comments should be addressed to improve clarity and consistency.

The search strategy needs more detail. Please provide the complete search strategy for at least one database. This would improve reproducibility. As the authors have mentioned only keywords and names of databases only.
Please clarify how medication adherence was defined during study selection. Some included studies assessed HbA1c, glucose control, or app engagement without directly measuring medication adherence.
HbA1c improvement should not be considered evidence of improved medication adherence unless adherence was also measured (although the authors did put that as a criteria in the methods, however, this criteria was violated later). Hence, This distinction should be applied throughout the manuscript.
Please clarify duplicate removal in the PRISMA flow diagram. The number of duplicates removed before screening should be reported.
Some cross-sectional associations are discussed as possible explanations or causal relationships (correlation does not mean causation). These interpretations should be reconsidered. The results mainly support associations.
In the intervention section, please distinguish between studies that directly measured medication adherence and those that only measured clinical or self-management outcomes.
The conclusion that adherence generally “tends to be low to moderate” may be too broad. The included studies used different tools and outcomes. 8. The manuscript requires substantial language editing, there are several repetitive and complex paragraphs.
"Medication adherence in the GCC region is not optimal. Reported adherence estimates varied widely according to the clinical setting, population, measurement instrument and adherence threshold." The finding should better reflect the purpose of a scoping review,, the review maps "scopes" the available evidence rather than providing a summarized evidence about the adherence across the GCC. The conclusions should therefore focus more on the variability of the available evidence, measurement approaches, research gaps, and areas requiring further investigation not answering/summarizing the adherence in GCC. Hence, this approach must be taken care of all over the study
The rationale for conducting this scoping review is not sufficiently clear. The Introduction states that no recent comprehensive synthesis is available for the GCC, but this alone does not clearly establish the need for the review. The specific knowledge gap should be better defined. In addition, a clear review question is missing. The authors should clarify what this scoping review is intended to map and what it adds to the existing literature (especially for a common disease like T2DM)

Author Response

Authors’ reply/modifications according to the reviewer 3 comments/suggestions

General:

Specific response to the reviewer’s suggestions:

Kindly find the attached response to each question one by one:

Overall comment: This is a relevant and useful scoping review on medication adherence among patients with T2DM in GCC countries. It investigates the variation in adherence levels, measurement tools, associated factors, and interventions. However, a few points and comments should be addressed to improve clarity and consistency.

Response: Thanks for the comments. The authors are pleased to hear the reviewer’s positive assessment of the manuscript. In accordance with the reviewer’s suggestions, we have made the necessary revisions to improve the clarity and consistency of the manuscript.

Point 1: The search strategy needs more detail. Please provide the complete search strategy for at least one database. This would improve reproducibility. As the authors have mentioned only keywords and names of databases only.

Response 1: Thank you for this valuable suggestion. In accordance with the reviewer’s recommendation, we have expanded the search methodology and provided detailed database-specific search strategies in Supplementary Table S2 to improve reproducibility.

Point 2: Please clarify how medication adherence was defined during study selection. Some included studies assessed HbA1c, glucose control, or app engagement without directly measuring medication adherence.

Response 2: Thank you for this valuable comment. In accordance with the reviewer’s suggestion, we have clarified the definition of medication adherence during study selection and distinguished direct adherence measures from clinical and digital engagement outcomes in the revised manuscript.

Point 3: HbA1c improvement should not be considered evidence of improved medication adherence unless adherence was also measured (although the authors did put that as a criteria in the methods, however, this criteria was violated later). Hence, This distinction should be applied throughout the manuscript.

Response 3: Thank you for this important comment. In accordance with the reviewer’s recommendation, we have revised the manuscript to consistently distinguish medication-adherence outcomes from HbA1c and other clinical outcomes, avoiding the interpretation of improved glycaemic control as direct evidence of improved adherence.

Point 4: Please clarify duplicate removal in the PRISMA flow diagram. The number of duplicates removed before screening should be reported.

Response 4: Thank you for this helpful comment. We have clarified the duplicate-removal process in the revised PRISMA flow diagram. Duplicate or overlapping reports (n = 30) were excluded during the full-text eligibility assessment, as indicated in Figure 1.

Point 5: Some cross-sectional associations are discussed as possible explanations or causal relationships (correlation does not mean causation). These interpretations should be reconsidered. The results mainly support associations.

Response 5: Thank you for this important comment. In accordance with the reviewer’s recommendation, we have revised the Results and Discussion to emphasise associations rather than causal relationships, particularly for findings derived from cross-sectional studies.

Point 6: In the intervention section, please distinguish between studies that directly measured medication adherence and those that only measured clinical or self-management outcomes.

Response 6: Thank you for this valuable comment. In accordance with the reviewer’s recommendation, we have revised the intervention section to clearly distinguish studies directly measuring medication adherence from those reporting only clinical or self-management outcomes.

Point 7: The conclusion that adherence generally “tends to be low to moderate” may be too broad. The included studies used different tools and outcomes. 8. The manuscript requires substantial language editing, there are several repetitive and complex paragraphs.

Response 7: Thank you for this helpful comment. In accordance with the reviewer’s suggestion, we have revised the Conclusion to emphasise study-specific variations in adherence rather than making broad generalisations across GCC countries. Furthermore, we have carefully edited the manuscript to improve grammar, clarity, and readability, while reducing repetitive wording and simplifying complex sentences throughout.

Point 8: "Medication adherence in the GCC region is not optimal. Reported adherence estimates varied widely according to the clinical setting, population, measurement instrument and adherence threshold." The finding should better reflect the purpose of a scoping review,, the review maps "scopes" the available evidence rather than providing a summarized evidence about the adherence across the GCC. The conclusions should therefore focus more on the variability of the available evidence, measurement approaches, research gaps, and areas requiring further investigation not answering/summarizing the adherence in GCC. Hence, this approach must be taken care of all over the study.

Response 8: Thank you for this valuable comment. In accordance with the reviewer’s recommendation, we have revised the Abstract, Results, Discussion, and Conclusions to emphasise evidence mapping, methodological heterogeneity, and research gaps rather than presenting generalised regional adherence estimates.

Point 9: The rationale for conducting this scoping review is not sufficiently clear. The Introduction states that no recent comprehensive synthesis is available for the GCC, but this alone does not clearly establish the need for the review. The specific knowledge gap should be better defined. In addition, a clear review question is missing. The authors should clarify what this scoping review is intended to map and what it adds to the existing literature (especially for a common disease like T2DM).

Response 9: Thank you for this valuable suggestion. In accordance with the reviewer’s recommendation, we have clarified the specific knowledge gap and added an explicit review question in the Introduction to better establish the rationale and contribution of this scoping review.

The authors thank the reviewer once again for the positive and constructive comments.

Reviewer 4 Report (New Reviewer)

Comments and Suggestions for Authors

It is an interesting study because many scientist are not familiar with some of these regions. However there are some points need improvement

Abstract section please change "review findings" to "results" as it is written in the main section
In some partst of the manuscript the meaning is no clear. For example lines 85-88
Use the same term either glycaemic or glycemic not both of them
It could helpful if authors had table mentioning their main findings and the differences among regions
It could be more interesting if authors compared their findings with the western societies

Author Response

Authors’ reply/modifications according to the reviewer 4 comments/suggestions

General:

Specific response to the reviewer’s suggestions:

Kindly find the attached response to each question one by one:

Overall comment: It is an interesting study because many scientist are not familiar with some of these regions. However there are some points need improvement.

Response: Thank you very much for your positive and encouraging comment. We appreciate the reviewer’s recognition of the relevance of synthesizing evidence from Gulf Cooperation Council countries. We have carefully addressed the specific points raised and revised the manuscript accordingly.

Point 1: Abstract section please change "review findings" to "results" as it is written in the main section.

Response 1: Thanks for the comment. According to the reviewer’s comments, the abstract in the revised manuscript is changed (Review findings to Results).

Point 2: In some partst of the manuscript the meaning is no clear. For example lines 85-88.

Response 2: Thank you for this comment. We agree that some sentences required clarification. We have revised the sentence in lines 85-88 and made minor language edits to additional sentences in the Introduction to improve clarity and readability while preserving the original meaning.

Point 3: Use the same term either glycaemic or glycemic not both of them.

Response 3: Thank you for pointing this out. We have standardized the spelling throughout the manuscript and now consistently use “glycaemic.” The original spelling used in published reference titles has been retained as it appears in the source publications.

Point 4: It could helpful if authors had table mentioning their main findings and the differences among regions.

Response 4: Thank you for this helpful suggestion. We have added a concise summary table presenting the main findings, overall evidence patterns, key associated factors, and notable country-specific differences across the GCC. As the included studies used different adherence measurement tools, cut-off values, clinical settings, and patient populations, these findings are presented as country-specific evidence patterns rather than direct prevalence comparisons.

Point 5: It could be more interesting if authors compared their findings with the western societies.

Response 5: Thank you for this valuable suggestion. We have strengthened the Discussion by incorporating brief comparisons with evidence from Western populations across adherence levels, patient-related factors, therapy-related determinants, and adherence-improvement approaches. These comparisons highlight both similarities and context-specific differences between GCC and Western settings, while acknowledging methodological differences across studies.

The authors thank the reviewer once again for the positive and constructive comments.

Round 2

Reviewer 1 Report (New Reviewer)

Comments and Suggestions for Authors

Thank you.

Author Response

We sincerely thank the reviewer for their positive feedback and appreciation of our revised manuscript. We are pleased that the revisions have satisfactorily addressed the reviewer's concerns.

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

The authors have provided a thorough, highly satisfactory, and professional response to the previous round of review. I am pleased to recommend this manuscript for acceptance and publication in Healthcare.

Author Response

We sincerely thank the reviewer for their encouraging feedback and appreciation of our revisions and responses. We are grateful for the reviewer's positive evaluation and recommendation for acceptance and publication of our manuscript.

Reviewer 4 Report (New Reviewer)

Comments and Suggestions for Authors

Authors responded to every comment. However, in my opinion l8nes 111-113 could be omitted

Author Response

We sincerely thank the reviewer for their positive feedback and helpful suggestion. According to the reviewer’s suggestion, we have omitted the redundant sentence (previously lines 111–113) to improve the clarity and conciseness of the manuscript.

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

Line 48 and Line 51 - Use the term "diabetes mellitus".
Lines 75-77 - Provide appropriate reference.
Lines 85-86 - Provide appropriate reference.
Lines 93-95 - Provide appropriate reference.
Section 3.1. Medication Adherence Levels in GCC - I recommend presenting a table summarising the analysed studies, including the following elements: authors, country (region or city), study design, sample size and population, tools used to measure adherence, adherence levels, and key findings.
Section 3.3. Interventions and Strategies - This section could also be improved by summarising findings in a table, including intervention/strategy and impact on medication adherence.
Results and discussion could be separated.

Reviewer 2 Report

Comments and Suggestions for Authors

Enhancing Patient Care Through Better Medication Adherence: An Updated Review of Determinants and Interventions in Type 2 Diabetes Across Gulf Countries

Introduction

The authors should be consistent in using only one terminology, “adherence” or “compliance,” throughout the manuscript.

Line 61: Please rephrase the sentence as “A systematic review in 2023 found that...”

Lines 62-64: The article focuses on GCC countries; therefore, the Middle East's prevalence may confuse readers. So, please add more insights on prevalence in GCC countries by replacing the Middle East data.

Lines 81-83: “Recently, a systematic … medication regimens adequately.”. Missing reference to authenticate this information. Please add it. References 11 and 12 are cross-sectional studies, not a systematic review.

Lines 79-81 & Lines 83-85: The sentences in these lines repeated the same message. Please combine these as one sentence.

Lines 85-88: Again, both sentences in these lines address the same message. Please avoid the repetition (e.g., glucose control and complications).

There is clarity on the gap between the current literature evidence and the purpose of the review. In this regard, the consequences of medication non-adherence need to be comprehensively addressed, and more data from GCC countries could provide the platform for this review.

Line 99: “…collect evidence from recent studies (2020-2025).”. Why the particular period 2020-25? The authors should explain why they chose a limited time period.

Methods and Search Strategies

Please provide the details of the exclusion of articles in Figure 1 based on each criterion in the screening process and the criteria for inclusion and exclusion.

Lines 107-108: The authors mentioned Google Scholar in the resources section of the abstract, but not in the methods. Please be consistent with your statement.

Line 109: August 2025, which was inconsistent with the abstract (September 2025).

Line 119: “Exclusion criteria included articles.” Please change it to “Exclusion criteria for the articles were...”

Main text and findings

The author mentions they included 58 articles, but I guess some are missing in this section. Therefore, please provide the details of 58 studies in a Table with a description of the author’s name et al., year of publication, country, sample size, instrument used, percentage of adherence, and potential determinants of adherence (i.e., therapy-related, patient-related, healthcare system-related, etc.). This will help readers get more details.

The authors discussed the findings of around only 19 articles (references 16-34) under the sub-head of Medication Adherence Levels in GCC. What about the medication adherence levels in the remaining 39 articles?

Also, in the demographic factors section, only a few articles' findings were explored. What about the remaining articles?

Please revise the discussion section after incorporating the comprehensive details as mentioned above.

References

The authors found 58 full-text articles in this review. A total of 70 references in this review (58 articles already eligible for this review) might not be enough. The authors were either unsuccessful in including the results of eligible articles or in comprehensively interpreting the findings of the included articles in the context of other related evidence.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript presents valuable recent pieces of evidence on medication adherence among T2DM in GCC countries. The authors made efforts to list and interpret the findings. However, I have several comments:

1. there is inconsistency between the Abstract (January 2020–September 2025) and the Methods section (line 109: January 2020–August 2025)
2. the authors should provide a brief justification for selecting the 2020–2025 time window

3. Although the manuscript is described as a narrative review, it incorporates systematic/scoping features such as: defined databases, explicit inclusion/exclusion criteria, a study selection flowchart. It reads like a systematic review.

4. Main findings and Discussion, merge descriptive study findings with interpretive part. This makes it lengthy and difficult to follow. To improve structure and readability, the authors should ensure that “Findings” remain primarily descriptive and “Discussion” handles interpretation, explanation, and implications

5. The manuscript would benefit from condensing overlapping/repeated content and focusing on unique insights per country or per category.

6. The section describing Ramadan fasting,, is longer than necessary relative to the amount of supporting data. In several places, background descriptions of religious practices are provided without direct link to adherence

7. The manuscript alternates between the terms “compliance” and “adherence”. Modern terminology favors “adherence”, which is more patient-centered and does not mean blind obedience! Hence, please standardize terminology, use “adherence” except when quoting a scale or study that uses “compliance”.

Best