elcome to Medical statistics 医学统计学 Yu xiaojin余小金 Phd, Associate professor from Department of Epidemiology Biostatistics, public Health school xiaojinyu@seu.edu.cn1 Welcome to Medical Statistics 医学统计学 Yu xiaojin 余小金 Phd , Associate professor from Department of Epidemiology & Biostatistics ,public Health school xiaojinyu@seu.edu.cn