1038 lected 20 min later. Breath samples were analyzed by isotope ratio mass spectrometry (UBiT-IR300; Photal Otsuka Elec- tronics, Japan) and 2.5 (subtraction of baseline from sam- ple) was used as the cut-off value. Statistical analysis Statistical comparison of the two regimens was performed using with Fisher’s exact test. Data analysis was performed using the Statistical Package for Social Science (version 10.0; SPSS INC. Chicago, Illinois, U.S.A.). The level of significance was set at 0.05. RESULTS The 233 children consisted of 115 males and 118 females and mean age was 10 yr (ranged from 2 to 15 yr). There were no demographic differences between the children treated with the OAC and BAM regimens (Table 1). Of the 141 children treated with the OAC regimen, 105 were UBT negative after treatment. Of the 36 children who failed the OAC regimen, 26 were secondarily treated with the BAM regimen, of whom 21 became UBT negative. Table 1. Demographic characteristics of the study population (n=233) BAM (n=92) 40/52 10.4±3.4 OAC (n=141) 73/67 9.8±3.1 Sex* (male/female) Mean age±SD* (yr) *p value >0.05 OAC, omeprazole (1 mg/kg/ day)+amoxicillin (50 mg/kg/day)+clarith- romycin (15 mg/kg/day); BAM, bismuth subsalicylate (8 mg/kg/day)+ amoxicillin (50 mg/kg/day)+metronidazole (20 mg/kg/day). Table 2. Eradication rate of Helicobacter pylori treated with first- line triple regimens OAC, omeprazole+amoxicillin+clarithromycin; BAM, bismuth subsalicy- late+amoxicillin+metronidazole; UBT, urea breath test. Table 3. Eradication rate of Helicobacter pylori treated with sec- ond-line triple regimens UBT negative 105 (74%) 78 (85%) 183 (79%) UBT negative 6 (86%) 21 (81%) 27 (82%) UBT positive 36 (26%) 14 (15 %) 50 (21%) UBT positive 1 (14%) 5 (19 %) 6 (18%) J. Choi, J.Y. Jang, J.S. Kim, et al. Of the 92 children treated with the BAM regimen, 78 were UBT negative after treatment. Of the 14 children who failed the BAM regimen, 7 were secondarily treated with the OAC regimen, of whom 6 became UBT negative (Fig. 1). As the first-line therapies, the eradication rates of the OAC and BAM regimens were 74% and 85%, respectively, and the overall eradication rate of both first-line triple regimens was 79% (Table 2). Although the BAM regimen was more effective than the OAC regimen in eradicating H. pylori infec- tion, the difference did not reach statistical significance (p= 0.07). As the second-line therapies, the eradication rates of the OAC and BAM regimens were 86% and 81%, respec- tively, and the overall eradication rate of both second-line triple regimens was 82% (Table 3). Again, the difference between the two regimens was not statistically significant (p=0.53). After the second-line treatment, as both first and second-line the overall eradication rate of the OAC and BAM regimens was 90% (210/233). DISCUSSION The previous studies of H. pylori eradication according to antibiotic regimens were rare in Korean children. Bae et al. (9) reported 90% with BAM regimen in 1998, Choi et al. (10) reported 82% with OAC regimen in 2002. Both results were better than our results, which may reflect the increas- ing rate of antibiotic resistance with time, although we did not directly test the H. pylori sensitivity to antibiotics in this population. Bae et al. (9) also reported that triple therapy with BAM regimen was more effective and safe than dual thera- py with bismuth subcitrate and amoxicillin, eradication rate was 90% in group treated with triple regimen, 61% in group treated with dual regimen. However there have been no re- 233 children 141 with OAC 105 with UBT- 36 with UBT+ 92 with BAM 14 with UBT+ 78 with UBT- 105 with BAM 7 with OAC 5 with UBT+ 21 with UBT- 1 with UBT+ 6 with UBT- OAC BAM Overall OAC BAM Overall OAC, omeprazole+amoxicillin+clarithromycin; BAM, bismuth subsalicy- late+amoxicillin+metronidazole; UBT, urea breath test. Fig. 1. Treatment strategies and outcomes of the study population. OAC, omeprazole+amoxicillin+clarithromycin; BAM, bismuth sub- salicylate+amoxicillin+metronidazole; UBT, urea breath test.