1. The Chinese Evidence-based Medicine Center/The Chinese Cochrane Centre; West China Hospital; Sichuan University; Chengdu 610041 China
2. Department of Medical Administration; 363 Hospital Chengdu 610041 China
3. National Chengdu Center for Safety Evaluation of Drugs; West China Hospital; Sichuan University; Chengdu 610041 China
4. West China Medical School/West China Hospital; Sichuan University; Chengdu 610041 China
5. West China Hospital; Sichuan University; Chengdu 610041 China