Discussion on the selection of the effect model in a meta-analysis
We read the recently published study by Feng et al. entitled “The effectiveness and safety of Chinese herbal medicine in infertile women with luteal phase deficiency: a systematic review and meta-analysis” (1). Feng et al. aimed to assess the efficacy and safety of Chinese herbal medicine (CHM) by using meta-analysis and comparing it with conventional Western therapies (CWT) to elucidate the improvement in progestin and clinical pregnancy rates. However, after reviewing the literature, we would like to raise concerns regarding some important issues in the paper.
Firstly, in the results section of clinical pregnancy rates, the authors depicted that a random-effects model was adopted for the statistical analysis because of the significant differences in CHM formulations. However, a fixed-effects model was actually shown in Fig. 3, which was not consistent with what the authors stated.
Secondly, in the results section of statistical analysis, Feng et al. stated that data were pooled by a random-effects model if a high heterogeneity was found among included studies. However, as seen in Figs. 4,5, the enrolled articles were considered to be significantly heterogeneous (I2=94% and I2=85%). Therefore, we believe that the random-effects model should be adopted, whereas the authors actually adopted a fixed-effects model to perform the meta-analysis.
In summary, Feng et al. showed a significant clinical issue concerning CHM in infertile women with luteal phase deficiency. However, the results of this study should be interpreted warily due to the issues above.
Acknowledgments
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References
- Feng H, Zhou H, Shang Y. The effectiveness and safety of Chinese herbal medicine in infertile women with luteal phase deficiency: a systematic review and meta-analysis. Ann Palliat Med 2022;11:2492-502. [Crossref] [PubMed]
