1. West China Hospital, Sichuan University; Department of Gerontology; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
2. West China Hospital, Sichuan University; Department of Geriatrics; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
3. West China Hospital, Sichuan University; Chinese Cochrane Centre, Chinese Clinical Trial Registry, Chinese Evidence-Based Medicine Centre, INCLEN Resource and Training Centre; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041