A positive PPI test was observed 93.2% of the ERD group and 87.2% of the NERD group during 2 weeks treatment (Table 2). There was no difference between two groups (p>0.05).
lansoprazole at a dose of 15 mg, 30 mg once daily 
lansoprazole at a dose of 60 mg once daily 
numbers of positive proton pump inhibitor (PPI) test