To assess the cost-utility of celecoxib in three treatment strategies for arthritis in Quebec, considering both upper gastrointestinal (GI) and cardiovascular (CV) events.
A Markov analytic framework was used to model patients with osteoarthritis and rheumatoid arthritis at low/average and high risk of GI and CV toxicity over 5 years with monthly cycles. Treatment strategies were modelled in line with Canadian clinical practice. In first-line treatment, patients started on celecoxib; second-line, patients started on a non-selective non-steroidal anti-inflammatory drug (NSAID) and switched to celecoxib after a first GI event; third-line, patients started on a non-selective NSAID, added a proton pump inhibitor (PPI) after a first GI event, and switched to celecoxib after a second GI event (while maintaining the PPI). Model inputs were determined through comprehensive literature searches (MEDLINE and EMBASE) from 1995 to 2006. Included studies evaluated GI (dyspepsia, uncomplicated and complicated ulcers, death) and CV (myocardial infarction, stroke, death) events. Drug and procedure costs were derived from Canadian published sources (Can$2005).
Total costs per patient for celecoxib first-, second-, and third-line treatment were Can$4,790, $3,390, and $3,466, and total quality-adjusted life-years (QALY) were 3.251, 3.231, and 3.230, respectively. In all risk categories, celecoxib second-line was less costly and as effective as celecoxib third-line, producing savings to the healthcare system. Although celecoxib first-line generated incremental expenditures versus celecoxib second-line, it was also more effective. The resulting cost-utility ratio for the high-risk population was Can$54,696/QALY. Based on this analytical approach, a treatment strategy where celecoxib is used before the combination of a non-selective NSAID plus a PPI possesses cost advantages for the Quebec provincial drug programme. One-way sensitivity analysis (varying GI and CV event rates, utilities, and cost) generally showed second-line treatment with celecoxib as the dominant strategy compared with third-line treatment with celecoxib.
Although effectiveness of second- and third-line celecoxib use is similar, total cost is lower for second-line. These results suggest that the use of celecoxib before the combination of a non-selective NSAID plus a PPI is relatively cost-effective in the treatment of arthritis pain and support the full benefit listing of celecoxib in Quebec's drug programme.