1. Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University , Guangzhou, Guangdong , PR China
2. Department of Neurology, The Eighth Affiliated Hospital of Sun Yat-sen University , Shenzhen, Guangdong , PR China
3. Department of Statistics, The Pennsylvania State University , State College, Pennsylvania , USA
4. Division of Public Health Sciences, Washington University School of Medicine in St. Louis , St Louis, Missouri , USA
5. Department of Scientific Affairs, Hugobiotech Co , Beijing , PR China
6. Department of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania , Philadelphia, Pennsylvania , USA