Funding for this research was provided by:
National Research Council Sri Lanka (15-033)
Commonwealth Scholarship Commission of the UK (LKCN-2015-100)
Received: 8 July 2019
Accepted: 23 January 2020
First Online: 30 January 2020
Ethics approval and consent to participate
: The present study was approved by the Ethics Review Committee, Faculty of Medicine, University of Colombo, Sri Lanka (EC/14/160). Written informed consent form at the time of enrolment was obtained from each patient.
: Not applicable.
: The authors declare that they have no competing interests.