Duration and dosage of PPI therapy for a one year continuous period for patients on PPI therapy for ≥3 months at maximum therapeutic dosage. Notes: One year period- January 2007 to January 2008, February 2007 to February 2008. Dosage is the dose at the end of each month. Maximum therapeutic dose= 40 mg/daily omeprazole, pantoprazole and esomeprazole. 30 mg/daily lansoprazole and 20 mg/daily rabeprazole. Maintenance therapeutic dose=10-20 mg/daily omeprazole, 20 mg/daily pantoprazole and esomeprazole. 15 mg/daily lansoprazole and 10 mg/daily rabeprazole.