1. Chinese Evidence-based Medicine Center; West China Hospital, Sichuan University; No. 37 Guo Xue Xiang; 610041; Chengdu; Sichuan; China
2. School of Public Administration; Sichuan University; No. 24 South Section 1, Yihuan Road; 610065; Chengdu; China
3. Chinese Evidence-based Medicine Center; West China Hospital; Sichuan University; No. 37 Guo Xue Xiang; 610041; Chengdu; Sichuan; China
4. School of Medicine; Queen's University Belfast; University Road Belfast; BT7 1NN; Northern Ireland; UK
5. West China School of Medical; Sichuan University; No. 37 Guo Xue Xiang; 610041; Chengdu; Sichuan; China