Article History
Received: 24 August 2017
Accepted: 4 April 2018
First Online: 10 April 2018
Ethics approval and consent to participate
: The conduct of this study was approved by the ethical review committee of the School of Public Health, College of Health Sciences, Addis Ababa University. Informed written consent to participate in the study was obtained from all participants.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.