S1. Definition of high-risk individuals.

Item	Risk level
*, Hot food means that the temperature of food is over 70 ℃, and hard food generally refers to food that is difficult to digest. **, Including gastric ulcer, superficial gastritis, atrophic gastritis.
Smoking at least 20 cigarettes per day and last for 10 years or more	1
Drinking at least 28 g ethanol per day and last for 10 years or more	1
Eating salt-preserved food at least once per week	1
Eating habit of very hot and hard food*	1
Family history of upper gastrointestinal cancer	2
Current symptom of chest pain, pressure or burning	2
Dysphagia	2
Chronic heartburn or indigestion	2
Vomiting or hemoptysis	2
Progressive weight loss	2
Esophageal reflux	2
History of gastric disease**	2