Comparative Risk of Clostridium difficile Infection between Proton Pump Inhibitors and Histamine‐2 Receptor Antagonists: A 15‐year Hospital Cohort Study Using a Common Data Model

BACKGROUNDS AND AIM: There are potential concerns regarding infectious complications including Clostridium difficile infections (CDIs) among patients taking gastric acid suppressants. Furthermore, it is speculated that the stronger acid suppression by proton pump inhibitors (PPIs) potentially enhance infectious complications. This study aimed to compare the risk of CDI between PPIs and histamine-2 receptor antagonists (H2RAs). METHODS: Using the long-term database of the Kangdong Sacred Heart Hospital, converted to the Observational Medical Outcomes Partnership Common Data Model, we identified outpatients treated with PPIs and H2RAs for >/= 7 days from January 1, 2004 through December 31, 2018. We conducted Cox regression analysis to examine the hazard ratio (HR) of CDI after propensity score matching. RESULTS: During a median follow-up period of 1.2 years (interquartile range, 0.2-3.2 years), the initial CDI occurrence differed significantly between matched cohorts of patients taking PPIs and H2RAs [PPIs vs H2RAs, 88/31 095 person years vs 47/32 836 person years; HR, 2.22; 95% confidence interval (CI) 1.29-3.96; P = 0.005]. Almost 50% of all events occurred within 1 year of drug exposure. The risk of CDIs was significantly greater among groups receiving PPIs or H2RAs than in matched controls (PPIs vs control: HR, 2.65; 95% CI 1.28-5.79; P = 0.011; and H2RAs vs control: HR 2.43; 95% CI 1.09-5.68; P = 0.034]. CONCLUSION: In long-term hospital cohort, outpatient-based PPIs were associated with greater risk of CDI than H2RAs. It is necessary to be cautioned about complication of CDI in patients taking long-term PPI therapy.