Department of Gastroenterology, Nippon Medical School, Graduate School of Medicine, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-8603, Japan

Jun Omori, Mitsuru Kaise & Katsuhiko Iwakiri

Department of Gastroenterological Endoscopy, Tokyo Medical University, Tokyo, Japan

Naoyoshi Nagata & Kuniko Miki

Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, Tokyo, Japan

Naoyoshi Nagata & Kazuhiro Watanabe

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan

Tomonori Aoki & Atsuo Yamada

Department of Gastroenterology, Tokyo Metropolitan Bokutoh Hospital, Tokyo, Japan

Katsumasa Kobayashi

Department of Gastroenterology and Hepatology, Kitano Hospital, Tazuke Kofukai Medical Research Institute, Osaka, Japan

Atsushi Yamauchi

Department of Gastroenterology, St. Luke’s International University, Tokyo, Japan

Takashi Ikeya

Department of Gastroenterology, Hiroshima City Asa Citizens Hospital, Hiroshima, Japan

Taiki Aoyama

Department of Gastroenterology, Saga-Ken Medical Centre Koseikan, Saga, Japan

Naoyuki Tominaga

Division of Gastroenterology and Hepatology, Department of Internal Medicine, St Marianna University School of Medicine, Kanagawa, Japan

Yoshinori Sato

Department of Gastroenterology and Hepatology, Center for Digestive and Liver Diseases, Nara City Hospital, Nara, Japan

Takaaki Kishino

Department of Gastroenterology, Tokyo Shinagawa Hospital, Tokyo, Japan

Naoki Ishii

Department of Endoscopy, Nagoya University Hospital, Aichi, Japan

Tsunaki Sawada

Department of Gastroenterology, National Hospital Organization Kyoto Medical Center, Kyoto, Japan

Masaki Murata

Department of Gastroenterology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan

Akinari Takao

Department of Gastroenterology, Oita University, Oita, Japan

Kazuhiro Mizukami

Department of Gastroenterology, Fukuoka University Chikushi Hospital, Fukuoka, Japan

Ken Kinjo

Department of Gastroenterology, Chiba Hokusoh Hospital, Nippon Medical School, Chiba, Japan

Shunji Fujimori

Department of Gastroenterology, Japanese Red Cross Shizuoka Hospital, Shizuoka, Japan

Takahiro Uotani

Division of Endoscopy and Ultrasonography, Department of Clinical Pathology and Laboratory Medicine, Kawasaki Medical School General Medical Center, Okayama, Japan

Minoru Fujita

Division of Gastroenterology, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan

Hiroki Sato

Department of Gastroenterology and Hepatology, Center for Digestive Disease and Division of Endoscopy, University of Miyazaki Hospital, Miyazaki, Japan

Sho Suzuki

Department of Gastroenterology, University of Tsukuba, Ibaraki, Japan

Toshiaki Narasaka

Division of Endoscopic Center, University of Tsukuba Hospital, Ibaraki, Japan

Toshiaki Narasaka

Department of Gastroenterology, Toranomon Hospital, Tokyo, Japan

Junnosuke Hayasaka

Emergency and Critical Care Center, Saiseikai Yokohamashi Tobu Hospital, Kanagawa, Japan

Tomohiro Funabiki

Department of Emergency Medicine, Fujita Health University Hospital, Aichi, Japan

Tomohiro Funabiki

Department of Gastroenterology, Naha City Hospital, Okinawa, Japan

Yuzuru Kinjo

Department of Internal Medicine, Tokyo Saiseikai Central Hospital, Tokyo, Japan

Akira Mizuki

Department of Gastroenterology, Shuto General Hospital, Yamaguchi, Japan

Shu Kiyotoki

Division of Endoscopy, Hirosaki University Hospital, Aomori, Japan

Tatsuya Mikami

Department of Gastroenterology and Hepatology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan

Ryosuke Gushima

Department of Gastroenterology and Hepatology, National Hospital Organization Fukuokahigashi Medical Center, Fukuoka, Japan

Hiroyuki Fujii

Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan

Yuta Fuyuno

Department of Gastroenterology, Fukushima Medical University, Fukushima, Japan

Takuto Hikichi

Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University, Iwate, Japan

Yosuke Toya

Department of Internal Medicine, National Defense Medical College, Saitama, Japan

Kazuyuki Narimatsu

Division of Endoscopy and Ultrasonography, Department of Clinical Pathology and Laboratory Medicine, Kawasaki Medical School, Okayama, Japan

Noriaki Manabe

Department of Gastroenterology and Hepatology, Suita Municipal Hospital, Osaka, Japan

Koji Nagaike

Department of Endoscopy, University of the Ryukyus Hospital, Okinawa, Japan

Tetsu Kinjo

Department of Gastroenterology, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan

Yorinobu Sumida

Department of Gastroenterological Endoscopy, Fukuoka University Hospital, Fukuoka, Japan

Sadahiro Funakoshi

Department of Gastroenterology, School of Medicine, Kitasato University, Kanagawa, Japan

Kiyonori Kobayashi

Department of Gastroenterology and Neurology, Akita University Graduate School of Medicine, Akita, Japan

Tamotsu Matsuhashi

Digestive and Lifestyle Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan

Yuga Komaki

Hygiene and Health Promotion Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan

Yuga Komaki

NN was the principal investigator in this study. JO and MK designed and conducted the study, performed statistical analysis, and wrote the paper. NN and TA mainly edited the paper and advised the statistical analysis. KK, AY, AY, TI, TA, NT, YS, TK, NI, TS, MM, AT, KM, KK, SF, TU, MF, HS, SS, TN, JH, TF, YK, AM, SK, TM, RG, HF, YF, TH, YT, KN, NM, KN, TK, YS, SF, KK, TM, YK, KM, KW, OG, and KI designed the study, made decisions and definitions of survey items, and interpreted the data. All the authors have read and approved the submitted version of the manuscript.