1. Division of Biostatistics, Graduate Institute of Epidemiology/Centre of Biostatistics Consultation, College of Public Health, National Taiwan University, Room 533, No. 17, Hsu-chow Road, Taipei, 100, Taiwan
2. Department of Otolaryngology Head and Neck Surgery, Buddhist Tzu Chi General Hospital, Taipei Branch, Taipei, Taiwan
3. School of Medicine, Tzu Chi University, Hualien, Taiwan, Taipei, Taiwan
4. Centre of Biostatistics Consultation, College of Public Health, National Taiwan University
5. Department and Graduate Institute of Health Care Management, Chang Gung University, Tao-Yuan, Taiwan