Received: 15 April 2019
Accepted: 21 July 2019
First Online: 26 July 2019
Ethics approval and consent to participate
: Ethical approval for the study was obtained from the Ethics Review Committee (ERC), Faculty of Medicine, University of Kelaniya, Sri Lanka. Written consent from all the participants were obtained prior to recruitment.
: Not applicable
: The authors declare that they have no competing interests.