An economic model for determining the costs and consequences of using various treatment alternatives for the management of arthritis in Canada

Objective: To construct a decision analytical model to compare the costs an d clinical consequences of treating patients with celecoxib or various nons teroidal anti-inflammatory drug (NSAID)/gastrointestinal (GI) co-therapy re gimens for the management of osteoarthritis and rheumatoid arthritis. The m odel quantified the number of patients expected to experience any GI compli cation commonly associated with NSAID therapy. Design: Resource use for the treatment of each GI complication in the model was estimated after consulting Canadian experts. Standard unit costs from Ontario were applied to resources to calculate the cost of each complicatio n. Main outcome measures and results: The model revealed that the NSAID-alone regimen was associated with the lowest cost [$262 Canadian dollars ($Can) p er patient per 6 months] followed by the celecoxib regimen ($Can273), diclo fenac/ misoprostol ($Can365), NSAID + histamine H-2 receptor antagonist ($C an413), NSAID + misoprostol ($Can421), and NSAID + proton pump inhibitor ($ Can731). A break-even analysis showed that up to 80% of the study cohort co uld be treated with celecoxib instead of the NSAID-alone regimen without in creasing the health system's overall budget. Celecoxib was associated with the fewest GI-related deaths, hospitalised events, symptomatic ulcers, and cases of anaemia. The celecoxib regimen was also associated with the fewest cases of upper GI distress. Sensitivity analyses revealed that the model w as most sensitive to the distribution of GI risk in the population and to t he ingredient costs of the treatment alternatives. Conclusions: This model indicates that the use of celecoxib could lead to t he avoidance of a significant number of NSAID-attributable Ct adverse event s, and the incremental cost of using celecoxib for arthritis patients great er than or equal to 65 years of age in place of current treatment alternati ves would not impose an excessive incremental impact on a Canadian provinci al healthcare budget.