Funding for this research was provided by:
Thailand Research Fund (RTA 488–0007, TRG5880200)
Commission on Higher Education (CHE-RES-RG-49)
Received: 16 October 2017
Revised: 12 January 2018
Accepted: 16 January 2018
First Online: 26 February 2018
Ethics approval and consent to participate
: The study was approved by the Siriraj Institutional Review Board (no. Si248/2011), in accordance with the Helsinki Declaration of 1975. All patients were provided with an explanation and with a participant information sheet and signed the informed consent.
: The authors declare that they have no competing interests.
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