Received: 11 September 2019
Accepted: 13 November 2019
First Online: 16 December 2019
Ethics approval and consent to participate
: As at the time this research was conducted, to the best of our knowledge, there was no ethical committee both at national and institutional level. However, all data were collected under previous consent of each participant.
: Not applicable.
: The authors declare that they have no competing interests.