150 S.-H. Park et al. Fig. 1. Flow diagram of subjects progress through the study duodenal bulb, and second part of the duodenum. An ulcer was defined as an excavated mucosal break 3 mm or more in diameter, measured with biopsy forceps or a custom-made device. Erosions were defined as superficial mucosal breaks, and intramucosal hemorrhages as hemorrhagic lesions without overlying mucosal breaks. Endoscopic mucosal damage was evaluated using the modified Lanza score, of 0 to 5, during the screening period and at the end of the study. Endoscopic diagnoses of subjects were reviewed after the study by four different endoscopists not participating in this study. Helicobacter pylori status was determined by CLO test (Kimberly-Clark Corporation, Irving, TX) during screening endoscopy. Unscheduled endoscopy Subjects who had intractable symptoms of dyspepsia, who were positive for occult blood in stool, had anemia (more than 1 g/dL decrease from baseline value of hemoglobin), hematemesis or hematochezia, or required rescue antacid consumption for more than 7 days underwent unscheduled endoscopy to ensure patient safety. Evaluation of adverse events Adverse events were of the following categories: (1) Symptoms of dyspepsia: the following gastrointestinal symptoms were to be recorded in the symptom diary-fullness, early satiety, bloating, nausea, vomiting, heartburn, and acid regurgitation. (2) Gastrointestinal complications, defined as intractable abdominal pain, intractable diarrhea, and intractable symptoms of dyspepsia. The criterion for intractable abdominal pain was moderate pain on the four-point scale lasting more than 3 days per week. The criterion for intractable diarrhea was more than 4 per day for more than 3 days per week. The criterion for intractable symptoms of dyspepsia was moderate pain on the four-point scale lasting more than 7 days between visits. End points The primary endpoint was the cumulative incidence of gastric or duodenal ulceration at 12 weeks. The secondary endpoint was the cumulative incidence of adverse events. Statistical analysis We referred to the results of a previous clinical trial in determining the trial size [10]. Equivalence of rebamipide to J. Clin. Biochem. Nutr.