Authors’ contributions
Dongmei Ma and Yan Chen contributed to study design, drafting of manuscript. Ping Chen, Jian Guo, and Lijia Peng contributed to study design and data collection. Lijia Peng contributed to data collection and analysis. Ping Chen contributed to data collection, and follow-up. Jianhong Xu contributed to data analysis and interpretation. All authors have read and approval the final manuscript. All authors declare that they have no conflict of interest.