1. Department of Critical Care Medicine, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
2. Department of Geriatric Medicine, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
3. Breast Disease Center, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China