1. Balıkesir University, Faculty of Medicine, Department of Public Health, 10145, Balıkesir, Turkey
2. Ege University Faculty of Medicine Department of Biostatistics and Medical Informatics, 35040 Bornova, İzmir, Turkey
3. Western University, Faculty of Medicine, Department of Epidemiology and Biostatistics, London- On, Canada
4. Nangarhar University, Faculty of Medicine, Department of Clinical Ophthalmology, Celalabad, Afghanistan