Proton-pump inhibitors and the risk of antibiotic use and hospitalisation for pneumonia.

Abstract

OBJECTIVE: To determine whether proton-pump inhibitor (PPI) use is associated with hospitalisations for pneumonia and with antibiotic use. DESIGN AND SETTING: Historical cohort study in the Australian veteran population, conducted from 1 January 2002 to 30 December 2006, comparing veterans exposed to PPIs with those not exposed. PARTICIPANTS: All 185,533 veterans who were Gold Card holders (ie, eligible for all health services subsidised by the Department of Veterans' Affairs) and aged 65 years and over at 1 January 2002 and had been prescribed at least one medicine in the previous 6 months. MAIN OUTCOME MEASURES: The primary endpoint was hospitalisation for pneumonia. Secondary endpoints included hospitalisation for bacterial pneumonia and dispensings of antibiotics commonly used to treat respiratory tract infections. RESULTS: After adjustment for potential confounders, we found an increased risk of hospitalisation for pneumonia among those exposed to PPIs compared with the unexposed group (rate ratio [RR], 1.16; 95% CI, 1.11-1.22). The risk was not increased for bacterial pneumonia (RR, 1.13; 95% CI, 0.98-1.31), which made up 8% of pneumonia cases. An increased risk of antibiotic dispensings was observed among those exposed to PPIs (RR, 1.23; 95% CI, 1.21-1.24). CONCLUSIONS: PPI dispensings were found to be associated with a small but significant increased risk of hospitalisation for pneumonia. While the increased risk is small, the prevalent use of PPIs means that many people could be affected.