1. Department of Nursing, College of Medicine and Health Sciences, Bahir Dar University, P.O. Box 79, Bahir Dar, Ethiopia
2. Department of Public Health, College of Medicine and Health Sciences, Debre Markos University, Debre Markos, Ethiopia
3. National Blood Bank, Addis Ababa, Ethiopia
4. Department of Nursing, College of Medicine and Health Sciences, Debre Markos University, Debre Markos, Ethiopia
5. Felege Hiwot Referral Hospital, Bahir Dar, Ethiopia