1. Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, Anhui, P.R. China
2. Internal Medicine, AMITA Health Saint Joseph Hospital Chicago, Chicago, IL, USA
3. Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
4. Division of Hospital Medicine, Department of Medicine, University of California, San Francisco, CA, USA
5. Chaohu Hospital of Anhui Medical University, Hefei, Anhui Province, P.R. China