Response to Comments on: “The effectiveness of high-intensity laser therapy in individuals with neck pain: a systematic review and meta-analysis”

Dear Editor,

Thank you for contacting us regarding the comments received on our published article titled “The Effectiveness of High-intensity Laser Therapy in Individuals with Neck Pain: A Systematic Review and Meta-Analysis” [[1]].

First, in the meta-analysis, the Neck Disability Index (NDI) scores for the experimental group and control groups were not the post-treatment NDI scores, but the difference between post-treatment and pre-treatment scores (i.e., change scores). Therefore, a greater positive value indicates more improvement (i.e., reduction in disability).

Second, during the peer review process, we were requested by the reviewers to use standardized mean difference (SMD) for the meta-analysis to take into account the high heterogeneity among the included studies.

Third, the 11-item PEDro scale is a widely used tool for assessing methodological quality of physiotherapy trials. The original RoB tool (7 items) is also commonly used and many of the items are similar to the PEDro. RoB 2 tool (21 items) is more comprehensive. It is acknowledged that the PEDro scale and Cochrane’s RoB 2 may lead to different sets of trials of adequate quality, and different combined treatment estimates from meta-analyses of trials [[2]]. However, some studies [3, 4] have found the Cochrane RoB 2 to be complex even for highly experienced raters, and its reliability is yet to be examined. On the other hand, the clinimetrics of PEDro has been well established [[5]].

Fourth, although the study by Shady et al. did not use placebo laser for comparison group, it did use conventional physiotherapy for comparison group, whereas the HILT group used HILT plus conventional physiotherapy. Therefore, the effect of HILT can still be delineated, which explains why this study was included in the meta-analysis in Fig. 1 [[1]]. Some of the data (i.e., cervical rotation in the study by Venosa et al.) were not available for meta-analysis.

Fig. 1Forest plot results for meta-analysis (weighted mean difference and 95% CI) of HILT on pain intensity compared with placebo. HILT: high-intensity laser therapy.

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Fifth, the study by Conforti et al. [[6]] was excluded because their study population had a diagnosis of whiplash injuries. Song et al. also did not include this study in their systematic review [[7]]. Perhaps it could have been made clearer in our review that neck pain caused by whiplash (trauma) would be excluded. The study by Alayat et al. [[8]] was excluded because the article showed that the mean power of the Multiwave Locked System laser was within 500 mW, which we did not consider to be HILT; and other two studies (Barassi et al. and Ahmed et al.) [9, 10] were excluded because the full text was not available for download from multiple sources.

Lastly, we acknowledge that the depth of action of HILT is indeed wavelength dependent, and this point may not have been made very clear in the manuscript.

In conclusion, we appreciate the insightful comments on our manuscript. While we acknowledge the limitations of the review, we believe that it still provides useful information for informing clinical practice in the treatment of neck pain.

Acknowledgements

None.

Ethical approval

N/A.

Funding

This study was supported by the Dongguan Science and Technology of Social Development Program (grant no. 20221800905692), China; and the Talent Development Foundation of the Dongguan First Affiliated Hospital of Guangdong Medical University (grant no. GCC2022004).

Conflict of interest

None.