However, the authors of an accompanying editorial said the findings of the study did not warrant a change to treatment recommendations on their own.
In the study, Dr Francis Chan of the Prince of Wales Hospital, Hong Kong, and colleagues from Spain and the US followed 4,484 patients with osteoarthritis or rheumatoid arthritis at increased GI risk.
Patients were either aged 60 years and over or aged 18 years and over with a previous GI ulceration.
They received either the COX-2 selective NSAID celecoxib or diclofenac plus omeprazole. Patients given celecoxib had around a 75 per cent lower risk of GI events.
After six months, 0.9 per cent of patients given celecoxib suffered a GI event, compared with 3.8 per cent in the other group. The researchers said the findings of their study were relevant to patients requiring anti-inflammatory therapy who are at increased GI but not increased cardiovascular risk.
'The findings of the trial should encourage guideline committees to review their treatment recommendations for arthritis patients,' Dr Chan and his team concluded.
But in a piece published alongside the study, Dr Elham Rahme and Dr Sasha Bernatsky, from McGill University in Canada, contested this point.
'Decreased risk of GI adverse events was driven mainly by haemoglobin decrease, not by documented lower GI bleeds,' they said.
'Thus, although the researchers close by suggesting revision of existing guidelines (which currently recommend selection of anti-inflammatory therapy on the basis of the patient's upper GI and cardiovascular risks), this advice might be premature.'