Funding for this research was provided by:
Ministry of Higher Education, Sri Lanka (PDN/0-Med/N4)
Received: 4 August 2019
Accepted: 8 January 2020
First Online: 16 January 2020
Ethics approval and consent to participate
: Ethical clearance for the study was granted by the committee on research and ethical review of the Faculty of Medicine, University of Peradeniya, Sri Lanka (2011/EC/02). Patient information sheets and consent forms were also approved by the same ethical review body. All subjects provided written informed consent to participate in the study.
: Provided by participants.
: The authors declare that they have no competing interests.