1. Department of Family Medicine & Polyclinics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
2. College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia
3. College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA
4. Department of Epidemiology and Scientific Computing, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia