1. Department of Psychiatry, Shanghai Tenth People’s Hospital, Anesthesia and Brain Research Institute, Tongji University School of Medicine, Shanghai, P. R. China
2. Department of Anesthesiology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, P. R. China
3. Tongji University School of Medicine, Shanghai, P. R. China
4. Biostatistics Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
5. Divisions of General Medicine and Primary Care and Gerontology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
6. Geriatric Anesthesia Research Unit, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA