[1] Chinese Peoples Liberat Army Gen Hosp, Med Ctr 2, Dept Gastroenterol, Beijing 100853, Peoples R China
[2] Natl Clin Res Ctr Geriatr Dis, Beijing 100853, Peoples R China
[3] Chinese Peoples Liberat Army Gen Hosp, Med Ctr 2, Inst Geriatr, Dept Epidemiol, Beijing 100853, Peoples R China
[4] Chinese Peoples Liberat Army Gen Hosp, Med Ctr 2, Off Informat Management, Beijing 100853, Peoples R China
[5] Chinese Peoples Liberat Army Gen Hosp, Med Ctr 2, Dept Clin Lab, Beijing 100853, Peoples R China