Letter to the editor on a recent paper on acupuncture with pelvic floor rehabilitation training

To the Editor,

Recently, we read the meta-analysis by Chu et al. ¹ on the therapeutic effect of acupuncture combined with pelvic floor rehabilitation training in treating postpartum stress urinary incontinence. The authors of this research should be congratulated on their research. However, we consider that there are some aspects of the review that merit further attention.

According to the title of the article, the treatment group mainly received acupuncture treatment. However, some of the articles included by the authors were a combination of acupuncture and moxibustion, which may affect the outcome. Acupuncture treatment uses thin metal needles inserted into acupoints to treat diseases, ² while moxibustion, which involves burning moxa or herbs at acupoints to heat them up and achieve therapeutic effects. ³ These are different techniques.

The frequency and types of acupuncture are key issues in delivering acupuncture therapy, ⁴ and so we are surprised that the authors did not conduct subgroup analysis for these differences. Indeed, the heterogeneity in some of the results from these included randomized controlled trials was relatively high (such as I² = 82%). Given the significant and substantial heterogeneity, we thought the authors should have conducted subgroup analysis or meta-regression based on factors such as age, gender, race, and disease duration to explore potential sources of heterogeneity. The subgroup analysis in this study was based solely on intervention measures and duration, without delving into other potential factors that could affect efficacy. ¹ Understanding such factors is important to enhance the comparability and reliability of research findings.

Although the acupuncture group had a lower incidence of adverse events and withdrawal rate, it is worth noting that all 21 studies included were conducted in China. ¹ The review neglected to discuss the influence of cultural biases in this regard. In other words, the research did not investigate the possible influence of differences in cultures on the efficacy or treatment compliance. Previous studies have found that participants’ cognitive levels regarding acupuncture, as well as differences in race and cultural background, may have an impact on the therapeutic effects of acupuncture.^5,6

Moreover, we were also interested to note that, in the research protocol published by the authors, ⁷ the authors reported they would be using the Grading of Recommendations Assessment, Development, and Evaluation methodology (GRADE) to evaluate the quality of evidence. However, in the review, this meta-analysis only uses the Cochrane Handbook for Systematic Reviews of Interventions, and no explanation is offered for this deviation. We also think that using objective Begger's and Egger's tests to identify potential publication bias in the meta-analyses, instead of relying on the visual assessment of funnel plot symmetry, would have been more appropriate.

In conclusion, the results from this review are important, but we think important issues have been overlooked by the authors.