To the Editor We read with great interest the article by Lazarus et at1 in a recent issue of JAMA Internal Medicine. The authors presented an interesting topic of significant relevance for our everyday practice, especially considering the epidemic of proton pump inhibitor (PPI) prescriptions among our patients. Nevertheless, we believe that differences in the frequency of hospitalizations should be considered when PPI users are compared with nonusers. Because a number of patients might have been started on a PPI after hospital discharge, we suppose that a higher frequency of hospitalization and consequently a higher risk of rehospitalization could explain the finding of a higher incidence of chronic kidney disease among PPI users. Notably, PPI users were more often obese and taking antihypertensive medications, 2 findings which can be considered potential risk factors for hospital-acquired acute kidney injury whose relationship with chronic kidney disease is well known.