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Thank you for your careful and thorough revisions. I have reviewed the updated submission myself, and no further external review was required at this stage. The manuscript shows clear improvement in methodological rigor, organization, and clarity.
We particularly appreciate that you extended your literature search to include studies up to October 2025, ensuring the review reflects the most current evidence base.
Your paper, “Virtual reality technology for upper and lower limb motor function, daily function, and balance in stroke patients: A Meta-Analysis of Randomized Controlled Trials,” has now been accepted for publication. Congratulations on your excellent work!
[# PeerJ Staff Note - this decision was reviewed and approved by Mike Climstein, a PeerJ Section Editor covering this Section #]
Thank you for your submission and careful work on this meta-analysis. After further editorial review, we have identified an important issue that must be addressed before the manuscript can be considered for publication.
Your current literature search ends in December 2024. For a meta-analysis, it is essential that the search be as up to date as possible to ensure all relevant studies are included. As it currently stands, studies published in 2025 would be omitted, which could compromise the validity and completeness of your findings.
We therefore request that you:
1) Extend your database search to cover studies published in 2025.
2) Incorporate any new eligible studies identified into your analyses.
3) Update the Results, Discussion, and Conclusions accordingly.
4) Revise the PRISMA flow diagram and search strategy details to reflect the updated search.
Once these revisions are completed, please resubmit the updated manuscript and provide a point-by-point response detailing the changes made.
We look forward to receiving your revised submission.
Thank you for your careful revision. The manuscript is much improved, and you have addressed the reviewers’ comments well. At this stage, only a few minor corrections are required before acceptance:
Please check for small grammar and word-choice issues. For example:
1) “The risk of bias assessments were categorised into three levels,, was would be the correct choice” → should be “were categorised … was”.
2) “These results are interpreted below in the context of existing literature and their implications are discussed.” → a comma after literature would improve readability.
3) “(i.g., haptic gloves vs. motion sensors)” → should be “(e.g., or i.e)”.
Please review the manuscript for spelling, spacing, and punctuation consistency (e.g., extra commas, misplaced spaces).
**PeerJ Staff Note:** Please ensure that all review, editorial, and staff comments are addressed in a response letter and that any edits or clarifications mentioned in the letter are also inserted into the revised manuscript where appropriate.
**Language Note:** When you prepare your next revision, please either (i) have a colleague who is proficient in English and familiar with the subject matter review your manuscript, or (ii) contact a professional editing service to review your manuscript. PeerJ can provide language editing services - you can contact us at [email protected] for pricing (be sure to provide your manuscript number and title). – PeerJ Staff
The manuscript has been substantially improved. The authors replied satisfactorily to reviewers’ comments and took into account the suggestions given.
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The revision is appropriate.
Overall, the writing is clear and comes with sufficient literature references. For the Retrieval Strategy section, what is going on with all the PubMed citations? It seems unreadable to me, a very strange format.
Also, there are some grammar mistakes here and there; the authors should scrutinize the entire manuscript in detail one more time.
This is a meta-analysis, so there is no original experimental design. The authors compared multiple publications and tried to demonstrate a concept.
This manuscript discusses many impacts that virtual reality technology may have on the human body, including lower and upper limb motor function, daily function, and balance. Each of the sections is relatively long, so it's hard to find the core point that the authors want to convey. Glad that the authors elaborate on the limitations compared to last time.
Please justify the need for this review in light of existing publication(s) as noted by Reviewer 2.
**PeerJ Staff Note:** Please ensure that all review, editorial, and staff comments are addressed in a response letter and that any edits or clarifications mentioned in the letter are also inserted into the revised manuscript where appropriate.
Section wise Comments:
Title:
The title is clear and descriptive, accurately reflecting the study’s focus on VR for stroke rehabilitation. However, consider specifying “upper and lower limb motor functions” to clarify that the study covers both, as “limb motor function” is somewhat vague.
Suggestion:
Revise to “Virtual Reality Technology for Upper and Lower Limb Motor Function, Daily Function, and Balance in Stroke Patients: A Meta-Analysis of Randomized Controlled Trials.”
Abstract:
The abstract is concise and summarizes the key findings effectively. However, it could better highlight the clinical implications of the results (e.g., how VR might be integrated into rehabilitation protocols).
The statement “The improvement of hand function and balance function was not statistically significant” is slightly misleading, as the p-value of 0.05 is borderline significant. Consider rephrasing to “The improvement in hand function and balance was not statistically significant at conventional thresholds (p=0.05).”
Suggestion:
Add a sentence on clinical implications, e.g., “These findings support the integration of VR into stroke rehabilitation to enhance motor and daily function, though further research is needed for hand function and balance.”
Introduction
The introduction provides a solid rationale for the study, citing global stroke burden and the potential of VR as a rehabilitation tool. The literature review is comprehensive, referencing key studies on stroke rehabilitation and VR.
However, the introduction could better articulate the specific gaps this meta-analysis aims to address. For example, it mentions limitations of prior studies (small sample sizes, short interventions) but does not explicitly state how this study overcomes these (e.g., by pooling larger samples or analyzing longer interventions).
The discussion of VR technologies (e.g., IREX, Xbox Kinect) is informative but could be streamlined to focus on their relevance to stroke rehabilitation.
Suggestion:
Add a sentence clarifying the study’s unique contribution, e.g., “This meta-analysis addresses these gaps by pooling data from 23 RCTs to evaluate VR’s efficacy across diverse intervention protocols and patient types.”
Materials and Methods
The methods are well-described, with clear details on search strategy, inclusion/exclusion criteria, data extraction, and statistical analysis. The use of PRISMA 2020, PROSPERO registration, and Cochrane tools enhances the study’s credibility.
Search Strategy:
o The search terms are appropriate, but the manuscript does not provide the full search strategy (e.g., Boolean operators, specific filters) as required by PRISMA item #7. This is noted as reported on pages 4-5, but the actual strategy is not included in the manuscript.
o Suggestion: Include the full search strategy for at one two database (e.g., PubMed) in the manuscript.
Inclusion/Exclusion Criteria:
o The criteria are clear, but the rationale for excluding non-English/Chinese studies is not discussed. This could introduce language bias, especially since VR research is conducted globally.
o Suggestion: Acknowledge this limitation in the Discussion and justify the language restriction (e.g., resource constraints).
Statistical Analysis:
o The use of Cohen’s d as the effect size measure is appropriate, but the manuscript does not specify why a fixed-effect model was used for moderate heterogeneity (I²=43.98% for daily function, 30.83% for balance). Fixed-effect models assume a single true effect size, which may not be appropriate for heterogeneous studies.
o Suggestion: Justify the use of fixed-effect models or consider re-running analyses with random-effects models for outcomes with moderate heterogeneity. Report both models if feasible.
• Subgroup Analysis:
o The subgroup analyses (training cycle, duration, patient type, intervention type) are well-conducted and provide valuable insights. However, the rationale for choosing these moderators is not explicitly stated.
o Suggestion: Add a sentence in the Methods explaining why these moderators were selected (e.g., based on clinical relevance or prior literature).
• Risk of Bias and Evidence Quality:
o The use of Cochrane’s risk of bias tool and GRADEpro is good. However, the manuscript notes that only a few studies achieved allocation concealment and complete outcome data, which could impact the reliability of results. This is acknowledged in the limitations but could be emphasized more in the Discussion.
o Suggestion: Discuss how these methodological limitations might have influenced the findings, particularly for non-significant results (hand function, balance).
Results
The results are clearly presented, with forest plots (Figures 4-7) and tables summarizing effect sizes and subgroup analyses. The inclusion of 23 RCTs with 779 patients strengthens the study’s statistical power.
Motor Function:
o The significant improvement in motor function (Cohen’s d=0.42, p<0.01) is well-supported, with low heterogeneity (I²=0%). The subgroup analysis showing a moderating effect of training cycle is insightful.
o However, the manuscript does not discuss the clinical significance of the effect size (Cohen’s d=0.42). Is this a small, moderate, or large effect in the context of stroke rehabilitation?
o Suggestion: Add a sentence interpreting the clinical relevance of the effect size, referencing established benchmarks (e.g., Cohen’s thresholds).
• Hand Function and Balance:
o The non-significant findings for hand function and balance (p=0.05) are intriguing, as they contrast with some prior studies (e.g., Shen et al., 2023). The manuscript acknowledges this but could explore potential reasons more thoroughly (e.g., differences in VR protocols, patient characteristics, or outcome measures).
o Suggestion: Expand the Discussion to hypothesize why VR was less effective for hand function and balance, considering factors like intervention intensity or measurement sensitivity.
• Daily Function:
o The significant improvement in daily function (Cohen’s d=0.22, p=0.02) is a key finding, but the moderate heterogeneity (I²=43.98%) suggests variability across studies. The use of a fixed-effect model here is questionable, as a random-effects model might better account for between-study differences.
o Suggestion: Re-analyze daily function with a random-effects model and compare results. Discuss the sources of heterogeneity (e.g., differences in outcome measures like FIM vs. MBI).
• Sensitivity Analysis:
o The sensitivity analysis confirms the robustness of results, which is reassuring. However, the manuscript does not specify which studies were excluded in the sensitivity analysis or how they impacted heterogeneity.
o Suggestion: Provide more details on the sensitivity analysis (e.g., which studies were removed and their impact on I²).
Discussion
• The Discussion effectively contextualizes the findings, comparing them to prior studies (e.g., Zhang et al., 2021; Laver et al., 2017) and highlighting the potential of VR in stroke rehabilitation.
• Motor Function:
o The discussion of motor function is robust, linking VR’s effectiveness to its immersive and interactive nature. The comparison to Moore et al. (2020) is relevant but could be expanded to discuss specific VR protocols (e.g., immersive vs. non-immersive).
• Hand Function:
o The explanation for the lack of effect on hand function (e.g., reliance on handheld controllers, reduced patient motivation) is plausible but could be supported with more references. The contrast with Rodríguez-Hernández et al. (2023) is noted, but the manuscript does not explore whether specific VR systems (e.g., gloves, haptic feedback) might yield different results.
o Suggestion: Discuss emerging VR technologies for hand rehabilitation (e.g., haptic gloves) and their potential to address current limitations.
• Daily Function:
o The discussion of daily function is strong, emphasizing VR’s role in improving independence and quality of life. The moderating effect of training cycle (5-8 weeks) is well-articulated, but the lack of effect for patient type and intervention type is underexplored.
o Suggestion: Hypothesize why patient type (sub-acute vs. chronic) did not moderate outcomes, considering neuroplasticity or disease stage.
• Balance:
o The non-significant finding for balance is surprising given prior evidence (e.g., Shen et al., 2023). The manuscript attributes this to study differences but could delve deeper into methodological factors (e.g., balance outcome measures like BBS vs. TUG, or VR tasks targeting balance).
o Suggestion: Discuss the sensitivity of balance outcome measures and whether VR protocols in the included studies were optimized for balance training.
• Limitations:
o The limitations section is adequate, acknowledging heterogeneity and methodological issues. However, it does not address the potential impact of excluding non-English/Chinese studies or the lack of long-term follow-up data.
o Suggestion: Add limitations related to language bias and the absence of long-term outcomes. Suggest future research to address these gaps.
• Clinical Implications:
o The manuscript briefly mentions VR’s potential to reduce economic burdens and improve quality of life but could provide more concrete recommendations for clinicians (e.g., optimal VR protocols, integration with conventional therapy).
o Suggestion: Include a paragraph on practical implications, such as recommended training cycles (5-8 weeks) and considerations for implementing VR in clinical settings.
Conclusion
• The conclusion summarizes the key findings and highlights VR’s potential in stroke rehabilitation. However, it could be more forward-looking, emphasizing specific research directions (e.g., optimizing VR for hand function and balance, long-term studies).
• Suggestion: Revise to include a call for future research on specific VR technologies and long-term outcomes, e.g., “Future studies should explore advanced VR systems, such as haptic feedback devices, and assess the sustainability of VR’s effects over extended follow-up periods.”
References
• The reference list is comprehensive and includes recent, relevant studies. However, some citations in the text (e.g., “World Stroke Organization, 2023”) are incomplete or unclear.
• Suggestion: Ensure all citations are complete and formatted consistently. Verify that all referenced studies are listed.
Supplemental Files
• The raw data (Excel file) is well-organized, providing detailed study characteristics and outcome measures. This enhances transparency.
• The PRISMA checklist is included and confirms adherence to reporting guidelines, though some items (e.g., funnel plot, flow diagram) are missing from the manuscript.
Additional Comments
1. Heterogeneity and Effect Size Interpretation:
o The manuscript reports I² values and uses fixed-effect models for moderate heterogeneity, which may underestimate variability. A random-effects model might be more appropriate for daily function and balance.
o The clinical significance of effect sizes (e.g., Cohen’s d=0.42 for motor function, 0.22 for daily function) is not discussed. Readers need context to understand whether these are meaningful improvements.
o Recommendation: Provide a brief interpretation of effect sizes (e.g., small, moderate, large) and consider random-effects models for outcomes with I²>25%.
2. Patient Stratification:
o The study includes both sub-acute and chronic stroke patients but does not explore whether outcomes differ by stroke severity or time since stroke. This could be a source of heterogeneity.
o Recommendation: If data permit, conduct exploratory analyses by stroke severity or time since stroke, or discuss this as a limitation and future research direction.
3. Publication Bias:
o The Egger test suggests no publication bias,
o Recommendation: Include the funnel plot and discuss any asymmetry, even if the Egger test is non-significant.
4. Long-Term Outcomes:
o The manuscript notes the lack of long-term follow-up as a limitation but does not elaborate on its implications. Long-term effects are critical for assessing VR’s sustainability in stroke rehabilitation.
o Recommendation: Emphasize the need for longitudinal studies in the Discussion and Conclusion.
Recommendations for Revision
Based on the above comments, I recommend major revisions before the manuscript is suitable for publication. The study has strong potential but requires improvements in methodological clarity, reporting completeness, and discussion depth. Specific action points include:
1. Clarify Statistical Methods:
o Justify the use of fixed-effect models for moderate heterogeneity or re-analyze with random-effects models.
o Provide the full search strategy and funnel plot in supplemental files.
o Interpret the clinical significance of effect sizes using established benchmarks.
2. Enhance Discussion:
o Explore reasons for non-significant findings (hand function, balance) in greater depth, integrating conflicting literature.
o Discuss emerging VR technologies (e.g., haptic feedback) and their potential to address current limitations.
o Add practical recommendations for clinicians, such as optimal training protocols.
3. Address Limitations:
o Acknowledge language bias from excluding non-English/Chinese studies.
o Discuss the impact of methodological limitations (e.g., allocation concealment, incomplete outcome data) on results.
o Emphasize the need for long-term follow-up studies.
4. Improve Language Clarity and Readability:
o Proofread the manuscript to correct grammatical errors and improve phrasing.
While generally clear, the manuscript contains grammatical errors and awkward phrasing (e.g., “shed lights on” [p. 8], “substandard studies” [p. 11], “State17” [p. 4]), these reduce readability for an international audience.
Examples needing revision include:
o Abstract, line 15: “State17 software” should be “Stata 17.”
o Introduction, line 85: “shed lights on” should be “shed light on.”
o Discussion, line 293: “requires creative therapy to recover effectively” is vague.
o Streamline the Introduction and Discussion to focus on key points.
5. Strengthen Subgroup Analyses:
o Provide a rationale for selected moderators in the Methods.
o If feasible, explore additional moderators (e.g., stroke severity, time since stroke) or discuss their absence as a limitation.
Conclusion
This meta-analysis provides valuable evidence supporting VR’s role in improving motor and daily function in stroke patients, with nuanced findings for hand function and balance. The study is methodologically sound and adheres to PRISMA guidelines, questionable statistical choices (fixed-effect models), and an underdeveloped discussion of non-significant findings and clinical implications.
The rationale for conducting a new meta-analysis on VR for stroke rehabilitation is not established. Many similar and rigorous meta-analyses already exist. Furthermore, the research question is vague and overly broad, addressing multiple outcomes (motor function, daily function, balance) without justification for combining such heterogeneous constructs.
Bargeri, S., Scalea, S., Agosta, F., Banfi, G., Corbetta, D., Filippi, M., ... & Gianola, S. (2023). Effectiveness and safety of virtual reality rehabilitation after stroke: an overview of systematic reviews. EClinicalMedicine, 64.
Search strategy (Table 1)- Many of the VR-related terms (e.g., "Educational Virtual Realities", "Instructional Virtual Reality") are not contextually appropriate for a clinical rehabilitation topic. These are typically used in education/learning environments rather than post-stroke therapy.
To comply with PRISMA standards and improve the transparency and reproducibility of systematic reviews and meta-analyses, the authors should clearly report the number of records identified from each database.
The authors report identifying only 1327 articles across five major databases, despite using a broad search strategy. However, even a simple query like ("virtual reality" AND "stroke") yields >1,500 records on PubMed alone. This discrepancy raises serious concerns about the reliability of the literature search process.
Risk of bias assessment- an outdated tool was used, please use the RoB 2 tool (a revised Cochrane risk-of-bias tool for randomized trials) and update the results and figures.
Sterne, J. A., Savović, J., Page, M. J., Elbers, R. G., Blencowe, N. S., Boutron, I., ... & Higgins, J. P. (2019). RoB 2: a revised tool for assessing risk of bias in randomised trials. bmj, 366.
GRADE assessment is inadequately applied and not aligned with current standards. No detailed downgrading rationale is provided.
The overall methodological rigor is poor. The manuscript does not provide enough evidence to support its conclusion that virtual reality significantly improves outcomes in stroke patients.
The conclusion overstates the findings, calling VR “effective” and “evidence-based” despite low-to-moderate certainty and non-significant findings on key outcomes.
Overall the manuscript is clear. Some issues:
1. line 17, "A total of 23 studies were included. Virtual reality technology is able to improve the
18 motor function (Cohen’s d=0.42, 95% CI 0.26-0.58, P=0.00)". P-value can't equal to zero, please double check.
2. Table 3, P-value can't equal to zero, please update reporting format
3. line 244-245 'Egger test showed that motor function (z = -0.93, Prob>|z|
245 =0.3522), hand function (z = 0.55, Prob >|z| = 0.5841), daily function (z =1.15, Prob>|z| = 0.2486).' reporting the p with probability compared to z is unprofessional, please update
Since this is a meta-analysis, authors compared multiple publications results and methodologies. No comment on the original research aspects.
In the content and also table 3/table 4, there are Q values mentioned, what is that?
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