Previous studies have associated the use of PPIs with an increased risk of community-acquired pneumonia (CAP) in a dose–response-like relationship. Gulmez et al. aimed to confirm this association by performing a large case-control study of the population of the County of Funen, Denmark.

http://www.nature.com/nrgastro/journal/v4/n9/full/ncpgasthep0885.html