Hiroki Sato, Haruhiro Inoue, Haruo Ikeda, Chiaki Sato, Chainarong Phlanusittepha, Shin-ei Kudo, Digestive Disease Center, Showa University, Northern Yokohama Hospital, Yokohama 224-8503, Japan
Bu’Hussain Hayee, Department of Gastroenterology, King’s College Hospital NHS Foundation Trust, London SE5 9RS, United Kingdom
Esperanza Grace R Santi, Department of Gastroenterology, De La Salle University Medical Center, Dasmariñas City 4114, The Philippines
Yasutoshi Kobayashi, Kobayashi Internal Medicine Clinic, Kobe 652-0812, Japan
Author contributions: Sato H drafted the manuscript; Inoue H supervised the study; Ikeda H, Sato C and Phlanusittepha C contributed to technical support; Hayee B, Santi EGR and Kudo S contributed to critical revision of the manuscript; and Kobayashi Y contributed to statistical analysis.
Ethics approval: This study was reviewed and approved by the Showa University Northern Yokohama Hospital Institutional Review Board.
Clinical trial registration: This study was registered at https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=history&action=list&type=summary&recptno=R000009120&language=J.
Informed consent: All study participants provided informed written consent prior to study enrollment.
Conflict-of-interest: There are no conflicts of interest.
Data sharing: No additional data are available.
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/
Correspondence to: Hiroki Sato, MD, PhD, Digestive Disease Center, Showa University, Northern Yokohama Hospital, 35-1 Chigasakichuo, Tsuzuki-ku, Yokohama 224-8503, Japan. email@example.com
Telephone: +81-45-9497000 Fax: +81-45-9497000
Received: October 2, 2014
Peer-review started: October 4, 2014
First decision: October 29, 2014
Revised: November 7, 2014
Accepted: January 8, 2015
Article in press: January 8, 2015
Published online: April 28, 2015