Authors’ contributions
Yue Liu and Xiaohong Guan contributed to the determination of study
topic and design of the study. Yue Liu and Yun Zhang mainly conducted
the article search, extracted the data, performed the assessment of
methodological quality of enrolled studies and pooled the results. Yue
Liu contributed to the original manuscript writing. Xiaohong Guan was in
charge of oversight and leadership responsibility for the research
activity planning and execution. All authors approved the final version
of the manuscript to be published.