Most of the studies of H. pylori eradication were conducted in academic institutes and designed to enrolled patients who did not have comorbidities. However, patients in the real world may comorbid with diabetes, chronic obstructive pulmonary disease, cirrhosis, chronic kidney diseases, or others. We hypothesize that the eradication rate of H. pylori in patients with comorbidity is poor because they may be infected with antibiotics-resistant H. pylori strains or have poor medication adherence. Here, we design a study, which focus on the H. pylori eradication rates by the various regimens in the real world, especially for those with high Charlson scores. It is presumed that our data will be helpful with regard to treating such patients with H. pylori eradication in the clinical scenario.

There is a challenge for eradicating Helicobacter pylori (H. pylori) because the resistant strains of H. pylori are increasing. In order to overcome the challenge, the new regimens are developed, including 14-day triple therapy, 10-day sequential therapy, 10-day bismuth-based quadruple therapy, 10-day concomitant therapy, or 14-day hybrid therapy, which have 84%~99% of successful eradication rates. Additionally, there is a new challenge, i.e., worldwide population aging and increases in the proportion of patients with comorbidity. Most of the studies of H. pylori eradication were conducted in academic institutes and designed to enrolled patients who did not have comorbidities. However, patients in the real world may comorbid with diabetes, chronic obstructive pulmonary disease, cirrhosis, chronic kidney diseases, or others. Our previous study showed that the eradication rate of 10-day clarithromycin-based sequential therapy was 81% in diabetic patients, lower than 87% in non-diabetic patients in other study. Therefore, we hypothesize that the eradication rate of H. pylori in patients with comorbidity is poor because they may be infected with antibiotics-resistant H. pylori strains or have poor medication adherence. The former is because patients may use macrolides because of chronic obstructive pulmonary disease with airway infection, for example. The latter is because the regimen of H. pylori eradication is complex, either three or four varieties of pills and dosage intervals for administration. Moreover, the patients may have taken many other medications for their underline comorbidity. These medications may have drug-drug interaction with the H. pylori eradication regimen or make the medication adherence poor. Most of studies which were conducted in academic institutes, patients took the H. pylori eradication regimen under the study staffs' instruction and monitor; however, in the real world, their medication adherence for H. pylori eradication may be compromised. Here, we design a study, which focus on the H. pylori eradication rates by the various regimens in the real world, especially for those with high Charlson scores. It is presumed that our data will be helpful with regard to treating such patients with H. pylori eradication in the clinical scenario.

Inclusion Criteria:

• Patients who are >= 20 years and received the therapy for H. pylori eradication from January 1, 2012 to December 31, 2019 are reviewed retrospectively. The regimens include 10- or 14-day sequential therapy, 7-, 10-, or 14-day triple therapy, 10- or 14-day hybrid therapy, 7- or 14-day concomitant therapy, 10- or 14-day bismuth-based quadruple therapy.

Exclusion Criteria:

• Patients are excluded if they ever received H. pylori eradication before.

This study is conducted at the outpatient department of National Cheng Kung University Hospital in Tainan, Taiwan. Patients who are diagnosed with H. pylori infection and receive H. pylori eradication in the hospital are the candidates to be reviewed.