Ling-Yin Chang1, Yu-Hsuan Lin2, Shio-Jean Lin3, Tung-Liang Chiang4. 1. Institute of Health Behaviors and Community Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan. 2. Surveillance, Research and Health Education Division, Health Promotion Administration, Ministry of Health and Welfare, Taiwan. 3. Department of Pediatrics, Chi Mei Medical Center, Tainan, Taiwan. 4. Institute of Health Policy and Management, College of Public Health, National Taiwan University, Taipei, Taiwan.