1. Evidence-based Medicine Center, Medical School of Nantong University; Nantong China
2. Medical School of Nantong University; Evidence-based Medicine Center; 19 Qixiu Road Nantong Jiangsu China 226001
3. West China Hospital, Sichuan University; Chinese Clinical Trial Registry, Chinese Ethics Committee of Registering Clinical Trials; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041