Alimentary Pharmacology and Therapeutics Haemoglobin decreases in NSAID users over time: an analysis of two large outcome trials J. L. Goldstein*, F. K. L. Chan , A. Lanas , C. M. Wilcox§, D. Peura–, G. H. Sands**, M. F. Berger**, H. Nguyen** & J. M. Scheiman *Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA. Department of Medicine and Therapeutics, Prince of Wales Hospital, Shatin, Hong Kong. University of Zaragoza, Aragon Health Research Institute (IIS Arago´n) CIBERehd, Spain. §Division of Gastroenterology/Hepa- tology, University of Alabama at Bir- mingham, Birmingham, AL, USA. –Division of Gastroenterology and Hepatology, University of Virginia Health Sciences Center, Charlottesville, VA, USA. **Pﬁzer Inc, New York, NY, USA. Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA. Correspondence to: Dr J. L. Goldstein, Department of Medicine, University of Illinois at Chicago, 840 South Wood Street (m ⁄ c787), Room 1020 - 10th Floor, Chicago, IL 60612, USA. E-mail: jlgoldst@uic.edu Publication data Submitted 4 March 2011 First decision 26 March 2011 Resubmitted 4 July 2011 Accepted 5 July 2011 EV Pub Online 2 August 2011 Re-use of this article is permitted in accordance with the Terms and Conditions set out at http:// wileyonlinelibrary.com/onlineopen# OnlineOpen_Terms 808 SUMMARY Background Nonsteroidal anti-inﬂammatory drugs (NSAIDs) have been associated with clinically signiﬁcant decreases in haemoglobin dependent and independent of acute bleeding events. Aim To evaluate the incidence and time to a clinically meaningful decrease in haemoglobin in two double-blind, prospective randomised clinical trials comparing NSAIDs in patients with osteoarthritis (OA) or rheumatoid arthritis (RA). Methods In CLASS, patients with OA ⁄ RA who were aged ‡18 years and required continuous NSAID treatment were included; patients who were Helicobacter pylori positive and ⁄ or using aspirin were not excluded. In contrast, in the CONDOR trial, comparing celecoxib alone to diclofenac sustained release (plus omeprazole), patients were aged ‡60 years or ‡18 years with a history of gastroduodenal ulcer and were H. pylori negative; aspirin or other anti- platelet users were excluded. To make a parallel post hoc analysis we limited our study to 6 months and the populations to only the non-aspirin users in CLASS and those patients receiving either celecoxib or diclofenac. A decrease in haemoglobin of ‡2 g ⁄ dL deﬁned the primary end point. Results At 6 months, in the CLASS and CONDOR trials, 1.9% and 2.0% of patients treated with celecoxib and 3.3% and 5.7% of patients treated with diclofe- nac developed a ‡2 g ⁄ dL decrease in haemoglobin, respectively, [CLASS: odds ratio (OR) 1.80 (95% conﬁdence interval (CI), 1.22–2.65) and CON- DOR: OR 2.93 (95% CI, 2.06–4.15), respectively]. Conclusion In these two large, independent trials, clinically-meaningful decreases in haemoglobin ‡2 g ⁄ dL occurred in a relatively similar fashion over time despite differences in trial designs. Aliment Pharmacol Ther 2011; 34: 808–816 ª 2011 Blackwell Publishing Ltd doi:10.1111/j.1365-2036.2011.04790.x