1. Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, Suita, Japan.
2. Department of Public Health, Faculty of Medicine, Beni-Suef University, Beni Suef, Egypt.
3. Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Korea.
4. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
5. Department of Public Health, Faculty of Medicine, Minia University, Minya, Egypt.
6. Department of Public Health, Yonsei University Graduate School, Seoul, Korea.