Contribution to authorship
Xiao-jun Chen and Jun Guan contributed to the study design and data interpretation. Zhi-ying Xu, Bing-yi Yang, Wei-wei Shan, Jiong-bo Liao, Wen-yu Shao, Peng-fei Wu, Shuang zhou, Cheng-cheng Ning, Xue-zhen Luo, Qin Zhu, Hong-wei Zhang and Feng-hua Ma contributed to the data collection. Zhi-ying Xu, Bing-yi Yang, and Jun Guan contributed to literature search, figures, tables and data analyses. This article was written by Zhi-ying Xu and Jun Guan. All authors critically reviewed the manuscript and approved the final version for submission.