1. Department of Epidemiology and Health Statistics; Public Health College, Qingdao University; Qingdao Shandong China
2. Epidemiology and Biostatistics, Department of Public Health; University of Southern Denmark; Odense C Denmark
3. Department of Neurology; Affiliated Hospital of Qingdao University; Qingdao Shandong China
4. Unit of Human Genetics, Department of Clinical Research; University of Southern Denmark; Odense C Denmark