1. Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, USA
2. Caritas-Egypt, Cairo, Egypt
3. Department of Community Medicine, Ain Shams University, Cairo, Egypt
4. Department of Public Health, Cairo University, Cairo, Egypt
5. Department of Nursing, School of Nursing & Health Studies, Georgetown University, Washington, DC, USA
6. Department of Oncology, Georgetown Lombardi Comprehensive Cancer, Georgetown University, Whashington, DC, USA