1 Department of Gastroenterology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China.
2 School of Population Medicine and Public Health, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China.
3 JC School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China.
4 Emergency Department, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China.
5 Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, Canada.
6 Centre for Health Economics and Policy Analysis, McMaster University, Hamilton, Canada.
7 State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China.
8 Clinical Epidemiology Unit, International Clinical Epidemiology Network, Beijing 100730, China.