Funding for this research was provided by:
Ministry of Health, Sri Lanka
Received: 18 April 2019
Accepted: 16 April 2020
First Online: 23 April 2020
Ethics approval and consent to participate
: The study is in accordance with Helsinki Declaration. The study protocol has been approved by the Ethics Committee of Colombo Medical Faculty (EC-15-081). Participants gave their informed consent.
: Not applicable.
: The authors declare that they have no competing interests.