OBJECTIVE: To evaluate the cost-effectiveness and the total cost differences between valdecoxib 10 or 20 mg qd and diclofenac 75 mg SR bid in the treatment of OA of the knee and/or hip.
METHODS: Study 063, a double-blind, randomized, 12-month study, evaluated the efficacy of valdecoxib 10 mg qd (n=259) and valdecoxib 20 mg qd (n=261) versus diclofenac 75 mg SR bid (n=262). Hospitalizations, unscheduled health care visits, concomitant medications and unscheduled diagnostic and medical procedures were prospectively collected during the trial. This economic evaluation was conducted from a UK National Health Service perspective, using published UK sources for cost. Cost per averted ulcer was used as a cost-effectiveness measure.
RESULTS: Valdecoxib 10 and 20 mg qd had comparable efficacy to diclofenac 75 mg SR bid at all time points; none of the 95% confidence intervals (CIs) overlapped 15 mm VAS, the smallest difference determined to be clinically meaningful. The overall incidence of adverse events was significantly lower in both valdecoxib groups than in the diclofenac group. Both valdecoxib groups demonstrated a lower mean number of hospital days (valdecoxib 10: 0.44 days; valdecoxib 20: 0.53 days; diclofenac: 1.02 days) and a smaller percentage of patients hospitalized (valdecoxib 10: 7.3%; valdecoxib 20: 8.4%; diclofenac: 9.5%). The valdecoxib 10 mg group resulted in lower mean total costs than the diclofenac group with a treatment cost difference of -£129.20 (95% CI: -£448.80, £190.39). The corresponding difference between the valdecoxib 20 mg group and the diclofenac group was -£79.74 (95% CI: -£400.92, £241.44). Cost per averted ulcer showed valdecoxib as the dominant therapy with fewer ulcers and lower total medical costs.
CONCLUSIONS: Valdecoxib 10 and 20 mg qd provided comparable efficacy with a more beneficial safety profile at a similar total medical cost compared to diclofenac 75 mg bid in treating OA.
