4484 cardiovascularly healthy patients with a clinical diagnosis of osteoarthritis or rheumatoid arthritis were randomized to be treated with either selective cox-2 inhibitor NSAID (celecoxib) or a combination of non-selective NSAID (diclofenac) and a proton pump inhibitor (omeprazole) for at least 6 months. After 6 months of treatment observation period, the rate of clinically significant GI events was 4 times higher in patients receiving diclofenac plus omeprazole over celecoxib. Subjective patient assessment via the Patient's Global Assessment of Arthritis showed no significant difference.