Authors’ contributions
All authors have read and approved the final manuscript. GL, CZ and YZ had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. GL, CZ and YZ are joint corresponding authors. Concept and design: JW, WZ, MD, ZSW, JAS, CZ, GL, YZ. Acquisition, analysis, or interpretation of data: All authors. Drafting of the manuscript: JW, CZ, GL, YZ. Critical revision of the manuscript for important intellectual content: All authors. Statistical analysis: JW, NL, XL, YZ. Administrative, technical, or material support: ZSW, JAS, CZ, GL, YZ. Supervision: WZ, MD, ZC, GL, YZ.