The accurate diagnosis of H. pylori infection is an important step for establishing the strategy for gastric cancer prevention. During endoscopy, rapid urease test (RUT) is the first of biopsy-based H. pylori tests. Despite indirect test for H. pylori detection, RUT shows rapid result with good sensitivity and specificity. Several study reported that H. pylori density was related to positive reaction time of RUT. However, there was no study comparing the positive reaction times of RUT according to biopsy site, degree of gastric atrophy, and intestinal metaplasia.

The aims of this study were to: (1) assess the positive reaction times of RUT in the body and antrum, (2) investigate the association between the difference of RUT results (body and antrum) and gastric atrophy, and intestinal metaplasia, and (3) evaluate the optimal biopsy site for RUT according to degree of gastric atrophy in Korean population.

Inclusion Criteria:

• Subjects who underwent upper endoscopy and rapid urease test

Exclusion Criteria:

• : age < 20 or > 70 years; anemia (serum hemoglobin level < 10 g/dL); severe systemic disease or advanced chronic liver disease; use of certain medications, including proton pump inhibitors, H2-receptor antagonists, or antibiotics; a history of H. pylori eradication; a history of gastric surgery; a recent history of upper gastrointestinal bleeding.

The subjects who underwent an upper gastrointestinal endoscopy were enrolled in this study at a single, tertiary-care, academic medical center. During endoscopy, rapid urease tests would be performed in the body and antrum.