Contribution to authorship
XB Chen and Y Chen contributed to the data analysis, chart making,
writing-reviewing and editing of the study. Data management and curation
were by Y Jiang. Data collection was by T Dong. Chart making was by J
Li. Software selection was by MM Yang. BH Zhao and Q Luo contributed to
the concept, design, data collection, chart making, writing- reviewing
and editing in the study and take responsibility for the accuracy of the
data analysis.