It has been suggested that the goal of H.pylori therapy should now be eradication in≥90% of treated patients[14]. There is a prospective clinical trials carried out in central-south of china found that the the eradication rate of IDFB (ilaprazole, doxycycline, furazolidon and colloidal bismuth tartrate) was 91.8% in PP analysis[15]. Another prospective clinical trials carried out in central-south of china found that the eradication rate of RADB (rabeprazole, amoxicillin, doxycycline and colloidal bismuth tartrate) was 93.8% in PP analysis[16]. In this large-sized retrospective study, we focus on patients don't receive antibiotics with high resistance and have good compliance. We found that the overall eradication rates in this special population is 91.4%. The result is consistent with previously reported eradication rates in the same area.
Eradication success was significantly associated with younger age, the eradication rate showed a significant decreasing trend with increase in age[17,18]. Our study showed that age≥45yrs was a significant risk factor for eradication failure. This finding is consistent with previous studies. Possible reasons for elderly groups have higher risk for eradication failure may include: 1.the aged population have more co-infection treatment maybe lead increased antibiotic resistance[18,19]; 2.Because of the hypertension, coronary artery disease and diabetes, the aged take more drugs, the possible drug interactions may lower the efficiency the quadruple therapy.
In this study, we also noticed that male is the risks for eradication failure. However, controversy exists over the role of gender as a risk factor. Our study and another prospective, nationwide, multi-center registry study in Korea both found out female sex was significantly associated with eradication success[18]. In contrast, some studies showed that female gender is the factor affecting H.pylori eradication failure[20,21]. However, those studies showed that the female gender is an unfavorable factor affecting eradication have something in common: the antibiotic regimens involve metronidazole, clarithromycin or levofloxacin. These antibiotics with high resistance were excluded in our study. This might be one of the reasons for different results. Therefore, the relationship between eradication failure and gender are needing further research.
Our study also analyzed the risk factors of the primary eradication population. Antibiotic abuse is a common phenomenon in china as medications are prescribed without supervision. Such an irrational use of antibiotics is responsible for the development of antibiotic resistance. Our study found that irrational use antibiotics without doctors` approve may cause H.pylori eradication failure. Government should strengthening antibiotics prescription supervision in order to improve eradication rates.
As we all know, H.pylori may be passed from person to person through direct contact with saliva. Always eating out may increase the risk of H.pylori infection of reinfection. However, to our best knowledge, this study maybe the first study found eating out is the risk factor associated with primary eradication failure. One reasonable guess is that people always eating out got more chance to exposure to the the resistant bacterial strains. Although, the relationship between eating out and eradication failure are needing further research.
We also found that in the absence of clarithromycin, metronidazole and levofloxacin, amoxicillin plus doxycycline, amoxicillin plus furazolidone and doxycycline plus furazolidone have almost the same efficiency in eradication H.pylori. Although numerous studies explored the eradication rates of various therapeutic regimens, most studies are involved clarithromycin or metronidazole, a few studies concerned only amoxicillin, furazolidone and doxycycline. A study showed that there was no significant difference between amoxicillin plus doxycycline and amoxicillin plus furazolidone in H.pylori eradication[22]. And another large-scale prospective, single-center clinical trial verified that the efficiency of amoxicillin plus furazolidone and doxycycline plus furazolidone are almost the same[23]. These findings were in consistent with our study. In addition to antibiotics, analyses were also performed according to different PPIs. However, we did not find various PPIs is associated with eradication failure.
The current study also presents some limitations: First, our study is a single center retrospective study, and the applicability of the results may be limited. Second, the antibiotics regimen and PPI regimen distribution in our study was uneven. The sample size of some antibiotics and PPIs are small, limit the reliability of the corresponding results. Finally, some important factors, such as bacterial strains and CYP2C19 genotype of patients were not included in our study. Future studies will be needed to include and analyses these factors.