1. Resident
2. Professor, Department of Anesthesia, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
3. Assistant Professor, Division of Biostatistics, Department of Medicine
4. Professor, Department of Anesthesia, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China.
5. Professor, Department of Anesthesia, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
6. Professor, Divisions of General Medicine and Primary Care and Gerontology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.
7. Associate Professor, Geriatric Anesthesia Research Unit, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts.