Andrew Ming-Liang Ong, Shu-Wen Tay, Yu-Tien Wang, Department of Gastroenterology and Hepatology, Singapore General Hospital, Singapore 169856, Singapore
Andrew Ming-Liang Ong, Yu-Tien Wang, Duke-NUS Graduate Medical School, Singapore 169856, Singapore
Author contributions: Ong AML wrote the manuscript and performed the research. Wang YT and Tay SW performed the research and contributed to the editing of the manuscript. All authors have approved the final version of the manuscript. The manuscript is original work of author. All data, tables, figures, etc. used in the manuscript are prepared originally by authors, otherwise the sources are cited and reprint permission should be attached.
Conflict-of-interest statement: The authors have no conflict of interest to declare.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Andrew Ming-Liang Ong, MBChB, MRCP, Assistant Professor, Doctor, Department of Gastroenterology and Hepatology, Singapore General Hospital, 20 College Road, Level 3, Academia Building, Singapore 169856, Singapore. firstname.lastname@example.org
Telephone: +65-6321-4684 Fax: +65-6227-3623
Received: April 22, 2019
Peer-review started: April 23, 2019
First decision: May 24, 2019
Revised: May 31, 2019
Accepted: June 10, 2019
Article in press: June 10, 2019
Published online: June 30, 2019