Yahya Al Farsi1, Rashid Al Abri2, Abdullah Al Hajri3, Shahid Al Balushi3. 1. Department of Family Medicine and Public Health, College of Medicine and Health Science, Sultan Qaboos University, Muscat, Sultanate of Oman. 2. ENT Division, Surgery Department, College of Medicine and Health Science, Sultan Qaboos University, Muscat, Sultanate of Oman. 3. Department of Operations Management & Business Statistics College of Economics and Political Science, Sultan Qaboos University, Muscat, Sultanate of Oman.