1 The First Clinical Medical School, Lanzhou University, Lanzhou 730000, China; Evidence-Based Medicine Center, School of Basic Medical Sciences and WHO Collaborating Centre for Guideline Implementation and Knowledge Translation, Lanzhou University, Lanzhou, China.
2 Evidence-Based Medicine Center, School of Basic Medical Sciences and WHO Collaborating Centre for Guideline Implementation and Knowledge Translation, Lanzhou University, Lanzhou, China.
3 Institute of Global Health, University of Geneva, Geneva, Switzerland; Institute of Mathematical Statistics and Actuarial Science, University of Bern, Bern, Switzerland.
4 Evidence-Based Medicine Center, School of Basic Medical Sciences and WHO Collaborating Centre for Guideline Implementation and Knowledge Translation, Lanzhou University, Lanzhou, China. Electronic address: chenyaolong@lzu.edu.cn.