1. West China Hospital, Sichuan University; Department of Pathology; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
2. West China Hospital, Sichuan University; Chinese Cochrane Centre, Chinese EBM Centre; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
3. Affiliated Hospital, Medical College of Yanan University; Cadre Wards; 250 Zhong Xin Street Yanan Shaanxi China 716000