Estimating the economic benefits of positive shifts in fibromyalgia severity: an exploratory analysis based on modeling of clinical trial data of pregabalin

Abstract

Objective:To estimate the annualized differences in direct medical and indirect costs associated with improvement in fibromyalgia (FM) severity among pregabalin-treated patients.Methods:Data from three clinical trials of pregabalin in patients with FM were modeled; efficacy results were extrapolated. Mean annual costs (direct and indirect) were assigned based on FM severity levels (mild: $10,219; moderate: $26,217; severe: $42,456). FM severity levels were defined using established cut-points on the Fibromyalgia Impact Questionnaire (FIQ). Mean annualized costs at end-point were estimated for all patients within each cohort and the mean differences in costs were compared using a regression model.Results:Relative to placebo, there was a significantly higher proportion of subjects with mild FM at end-point with pregabalin 450 mg and a significantly lower proportion of subjects with severe FM. Mean total costs were lower with pregabalin (300 mg, $25,721; 450 mg, $24,103) than placebo ($26,162). The difference in mean annual costs was $2059 lower for pregabalin 450 mg (p = 0.003) and $441 lower for pregabalin 300 mg (p = 0.52). Mean direct medical costs were higher with pregabalin (300 mg, $4962; 450 mg, $4820) than placebo ($4364). The difference in mean annual direct medical costs was significantly higher for pregabalin 450 mg by $456 (p < 0.0001) and by $599 for pregabalin 300 mg (p < 0.0001). Mean indirect costs for pregabalin (300 mg, $20,783; 450 mg, $19,306) were lower than placebo ($21,735). The difference in mean annual indirect costs for pregabalin 450 mg was lower by $2429 (p < 0.0001); pregabalin 300 mg was lower by $951 (p = 0.12).Limitations:Use of 13-week end-point data from clinical trials to extrapolate to annual costs and an assumption of continuous therapy over the course of 1 year.Conclusions:Improvements in FM severity were associated with overall reductions in cost. Reductions in indirect costs may offset the costs of treatment with pregabalin.