1. Division of Nephrology, Department of Internal Medicine, Yuan’s General Hospital, Kaohsiung 802, Taiwan
2. Division of Hepatogastroenterology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University, Kaohsiung 833, Taiwan
3. Graduate Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei 100, Taiwan
4. Taiwan Cancer Registry, Taipei 100, Taiwan
5. Department of Public Health, Kaohsiung Medical University, Kaohsiung 807, Taiwan
6. Department of Environmental and Occupational Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan