Haemoglobin decreases in NSAID users Figure 3 | Kaplan–Meier sum- maries in non-aspirin patients with haemoglobin decreases (‡2 g ⁄ dL) in the (a) CLASS and (b) CONDOR trials. *Estimated proportion at month 6. Table 3 | Aspirin users in CLASS (crude rates over 6 months) No decrease in haemoglobin, n (%) With a decrease in haemoglobin, n (%) Celecoxib N = 872 Diclofenac N = 438 841 (96.44) 412 (94.06) 31 (3.56) 26 (5.94) OR = 1.71 (1.00–2.92) DISCUSSION Our study demonstrates that continuous 6-month expo- sure to NSAIDs is associated with a clinically meaningful decrease in haemoglobin; a meaningful decline in Aliment Pharmacol Ther 2011; 34: 808–816 ª 2011 Blackwell Publishing Ltd haemoglobin was observed in all of the treatment arms in both trials in the absence of aspirin use. However, despite differences in the study design and population of the two trials, these results were reproducible for both. Furthermore, the studies demonstrated that patients trea- ted with diclofenac were two- to threefold more likely to reach the meaningful end point than patients treated with the COX-2 selective NSAID celecoxib. We believe that this information focused on the development of pro- gressive haemoglobin decreases with the chronic use of NSAIDs, independent of acute bleeding events, and high- lights the relatively understudied clinical issue of long- term chronic occult blood loss. A decrease in haemoglobin of ‡2 g ⁄ dL has previously been considered as a clinically meaningful end point18 in 813