Proton pump inhibitors: do they increase the risk of pneumonia?

There have been meta-analyses which have linked an increase in pneumonia with Proton Pump Inhibitors (PPI); however was this association due to confounding factors? This study by Othman et al (doi: http://dx.doi.org/10.1136/bmj.i5813) looked at 160 000 people who received a first dose of PPI who were part of the Clinical Practice Research Datalink(CPRD) a primary care research database. They carried out a self-controlled case series study along with a cohort study; those within the cohort study were matched for age sex and year of prescription. Potential confounders were extracted and evaluated. These were smoking, alcohol use, number of visits to their general practitioner in the year before PPI prescription, immunosuppression and comorbidities based on the Charlson index score. Those who were prescribed PPIs were more likely to have a history of smoking (42.9% vs 33.7% of their matched controls) and alcohol use (29.1% vs 23.9%); they also had a higher burden of comorbidity and used more corticosteroids and opioids. Most patients used PPIs for short periods median 28 days. There were …