1. Division of General Surgery, Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan, R.O.C.
2. Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan, R.O.C.
3. Center for Geriatrics and Gerontology, Kaohsiung Veterans General Hospital, Pingtung 900, Taiwan, R.O.C.
4. Laboratory Medicine Division, Zuoying Branch of Kaohsiung Armed Forces General Hospital, Kaohsiung 813, Taiwan, R.O.C.