To evaluate changes in health-care resource use and costs after initiating pregabalin or duloxetine in employees with fibromyalgia (FM).
Employees (18 to 64 years old) with at least one claim for an FM-attributable medication within 60 days following an FM diagnosis were identified using the Thomson Reuters MarketScan(®) Commercial Database (2006 to 2008). Patients newly initiated on pregabalin were propensity score matched to patients newly initiated on duloxetine. These treatment cohorts were evaluated for changes between the 6-month pre- and post-initiation periods in health-care utilization including prescriptions, imputed medically related work loss and expenditures. Pre- to post-initiation changes were compared between pregabalin and duloxetine using a difference-in-difference approach based on univariate statistics and multivariable models.
A total of 731 employees with FM initiated on pregabalin (89.9% female, mean age 47.1±9.7 years) were matched with 731 employees initiated on duloxetine (89.5% female, mean age 47.1±9.8 years); other demographic and clinical characteristics were also comparable between cohorts. The adjusted marginal effects were not statistically significant for pre- to post-changes in opioid utilization (P=0.856), number of FM-attributable (P=0.151) or FM-related medications (P=0.462), and all-cause (P=0.323) or FM-attributable (P=0.991) expenditures. Pregabalin was associated with a significantly lower probability of any medically related work loss of 3.2 percentage points (P=0.030) compared with duloxetine, but changes in indirect costs were not significantly different (P=0.600).
The changes in health resource utilization and costs after initiation of pregabalin were not significantly different than the changes observed after initiation of duloxetine. These results not only demonstrate an overall similarity of resource utilization, but also suggest cost neutrality between pregabalin and duloxetine.