1. West China Hospital, Sichuan University; The Center of Gerontology and Geriatrics; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
2. 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
3. West China Hospital, Sichuan University; Cochrane China; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041