1. Chinese Evidence-Based Medicine Center; West China Hospital, Sichuan University; Chengdu China
2. Department of Rheumatology and Immunology; West China Hospital, Sichuan University; Chengdu China
3. The Second People's Hospital; Mudanjiang China
4. Department of Teaching Affairs, West China Medical School; Sichuan University; Chengdu China
5. Centre for Evidence-Based Medicine and Clinical Research, Taihe Hospital; Hubei University of Medicine; Shiyan China
6. Department of Clinical Epidemiology and Biostatistics; McMaster University; Hamilton Canada