This trial will compare the retention on treatment (based on the rate of patients staying on treatment for 1 year) of patients suffering from primary osteoarthritis using two different doses of lumiracoxib (100 mg od or 100 mg bid) or using celecoxib (200 mg od)

Inclusion Criteria:

• Primary osteoarthritis in the hip, knee, hand, or spine
• Requiring NSAID therapy

Exclusion Criteria:

• Secondary OA with history and/ or any evidence of the following diseases: rheumatoid arthritis, uncontrolled gout, inflammatory joint disease, ochronosis, acromegaly, hemochromatosis, Wilson's disease, primary osteochondromatosis, heritable disorders (e.g. hypermobility), collagen gene mutations, primary fibromyalgia (secondary fibromyalgia is allowed if in the opinion of the investigator it will not interfere with the patient's OA pain assessment), and systemic lupus erythematosus
• History and/ or any evidence of the following diseases in the target joint: septic arthritis, gout, recurrent episodes of pseudogout, Paget's disease of the bone, and articular fracture. If the patient has history of these conditions, then patient should only be excluded if the target joint is affected.
• History of severe adverse reactions of any kind under lumiracoxib or celecoxib treatment.

Other protocol-defined inclusion/exclusion criteria may apply.