Sample size
Supposing the cure rate of the clarithromycin-based regimen and to the levofloxacin-based regimen is 69% versus 84.5% respectively, using Medcalc, the minimum required sample size was calculated as 116 patients for each arm (type 1 error = 5%, type II error = 20%). Each arm was increased by 10% to compensate for drop-out. The sample size was 135 for each arm. Two hundred seventy patients were enrolled.Patients aged 18–65 years old with newly diagnosed 