Disease Markers
Volume 2019 (2019), Article ID 9263862, 1 page
https://doi.org/10.1155/2019/9263862

Letter to the Editor

Comment on “Sex Differences in the Association between Night Shift Work and the Risk of Cancers: A Meta-Analysis of 57 Articles”

Pengfei Sun,¹ Minglei Bi,¹ Yipeng Su,² and Zhenyu Chen²

¹Department of Medicine, Qingdao University, 266000 Qingdao, China
²Department of Plastic Surgery, Affiliated Hospital of Qingdao University, 266000 Qingdao, China

Correspondence should be addressed to Zhenyu Chen; czy.plastic@126.com

Received 15 January 2019; Accepted 18 February 2019; Published 9 May 2019

Academic Editor: Fabrizia Bamonti

Copyright © 2019 Pengfei Sun et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

We carefully read the published study by Liu et al. about sex differences in the association between night shift work and the risk of cancer [1]. However, we found many problems in the article.

Firstly, according to the requirements of PRISMA [2], detailed retrieval strategies for at least one database should be provided in the article. But the author did not mention it in the article. They only provided keywords in the article instead.

Secondly, the authors stated in their article that they tested heterogeneity between studies using the statistic with indicating heterogeneity, and if no significant heterogeneity existed, a fixed effects model was adopted; otherwise, a random effects model was used. Although their statement was correct, they did not do so. For example, the random effects model should be used for the meta-analysis of (a) women (%) and (b) men (%) while the fixed effects model was used in Figure 2.

Thirdly, in the article, the dose-response analysis is not rigorous. A binary analysis of dose-response relationship should be performed before the dose-response analysis. If there is no statistical difference in the binary analysis of dose-response relationship, there is no need for the dose-response analysis.

Fourthly, publication bias will affect the final results of meta-analysis [3]. However, the article has obvious publication bias () and high heterogeneity, so we think the conclusion of the article is not credible.

In summary, based on the problems in the article, we question the final conclusion of the article.

Conflicts of Interest

The authors declare that there is no conflict of interests.

References

W. Liu, Z. Zhou, D. Dong, L. Sun, and G. Zhang, “Sex differences in the association between night shift work and the risk of cancers: a meta-analysis of 57 articles,” Disease Markers, vol. 2018, Article ID 7925219, 20 pages, 2018.

A. Liberati, D. G. Altman, J. Tetzlaff et al., “The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration,” BMJ, vol. 339, article b2700, 2009.

P. Sun and W. Zhao, “Be careful about heterogeneity and publication bias in meta-analysis,” Journal of Clinical Anesthesia, vol. 53, p. 76, 2019.