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Comment & Response
September 9, 2013

Harmful Effects of Proton Pump Inhibitors: Discrepancies Between Observational Studies and Randomized Clinical Trials—Reply

Author Affiliations
  • 1Section of Geriatrics, Department of Clinical and Experimental Medicine, University Hospital of Parma, Parma, Italy
  • 2Geriatric Rehabilitation Department, University Hospital of Parma, Parma, Italy
  • 3Unit of Geriatric Pharmacoepidemiology, Italian National Research Centres on Aging (INRCA), Cosenza, Italy
JAMA Intern Med. 2013;173(16):1559-1560. doi:10.1001/jamainternmed.2013.8459

In Reply We are grateful to Lalmohamed and coworkers for their constructive criticisms to our study.1 We are aware of the differences existing between data on proton pump inhibitors from randomized clinical trials/meta-analyses and those obtained from observational studies. We completely agree that the residual confounding is a relevant issue in the latter. Indeed, we extensively acknowledged this limitation in our study. We also agree that confounders not included in the analysis, such as alcohol consumption and use of systemic steroids, could also have affected the results. In our study, 14 of 491 patients (2.9%) reported a daily alcohol consumption exceeding half a liter of wine, and 47 (9.6%) had a systemic steroid prescribed at discharge. However, after adjusting for these 2 additional covariates, the association between use of proton pump inhibitors and mortality was substantially unaffected (hazard ratio, 1.55; 95% CI, 1.02-2.83) (P = .04).