The economic burden associated with fibromyalgia in the U.S. is substantial. The objective of this study was to compare changes in health care costs in fibromyalgia patients initiated on pregabalin and duloxetine in real-world settings.
Patients (≥ 18 years old) initiating pregabalin or duloxetine between June 1, 2007 and December 31, 2008 were identified using a U.S. managed care database. Patients were selected if they had ≥ 2 medical claims for fibromyalgia (ICD-9-CM, 729.1) at least 90 days apart or ≥ 1 claim for fibromyalgia followed within 30 days by a pharmacy claim for pregabalin. The date of the first pregabalin or duloxetine prescription was defined as the index date, and continuous enrollment for 6-month pre- and postindex periods was required.
A total of 1,616 pregabalin and 207 duloxetine patients were identified. Treatment differences between pregabalin and duloxetine in the pre-/postindex change in mean [SD] all-cause total health care costs ($1,307 [16,747] vs. -$158 [17,337]; P = 0.24) or fibromyalgia-related total health care costs ($584 [3,834] vs. $759 [2,133]; P = 0.32) were not significant. Multivariate analysis using difference-in-differences models showed no significant difference in all-cause costs (mean cost ratio = 1.05, 95% CI: 0.84 to 1.31) or fibromyalgia-related costs (0.85, 95% CI: 0.61 to 1.18) between treatments during the postindex period.
No significant differences were found between pregabalin and duloxetine in the pre- to postindex change in mean all-cause or fibromyalgia-related total health care costs.