Clinical comorbidities, treatment patterns, and healthcare costs among patients with fibromyalgia newly prescribed pregabalin or duloxetine in usual care

Objective: To assess comorbidities, pain-related pharmacotherapy, and healthcare resource use among patients with fibromyalgia (FM) newly prescribed pregabalin or duloxetine (index event) in usual care settings. Methods: Using the LifeLink™ Health Plan Claims Database, patients with FM (International Classification of Diseases, Ninth Revision, Clinical Modification code 729.1X) were identified. Patients initiated on duloxetine were propensity score-matched with patients initiated on pregabalin (n=826; mean age [standard deviation] of 48.3 [9.3] years for both groups). Prevalence of comorbidities, pain-related pharmacotherapy, and healthcare resource use/costs were examined during the 12-month pre-index and follow-up periods. Results: Both patient groups had multiple comorbidities and a substantial pain-related and adjuvant medication burden. In the pregabalin group, use of other anticonvulsants decreased significantly (31.6% vs 24.9%), whereas use of serotonin-norepinephrine reuptake inhibitors (SNRIs; 16.5% vs 22.5%) and topical agents (10.1% vs 13.2%) increased in the follow-up period (p<0.01). In the duloxetine group, there were significant decreases in the use of other SNRIs (13.0% vs 5.7%), selective serotonin reuptake inhibitors (41.3% vs 21.7%), and tricyclic antidepressants (18.8% vs 13.2%), and an increase in the use of anticonvulsants (28.6% vs 40.1%; p<0.0001). There were significant increases (p<0.0001) in pharmacy and total healthcare costs in both cohorts, and a significant increase in outpatient costs (p=0.0084) in the duloxetine cohort from pre-index to follow-up. There were no significant differences in median total healthcare costs between the pregabalin and duloxetine groups in both the pre-index ($$10,159 vs $$9,556) and follow-up ($$11,390 vs $$11,746) periods. Limitations: Limitations of this study are typical of those associated with retrospective database analyses. Conclusions: Patients with FM prescribed pregabalin or duloxetine were characterized by a significant comorbidity and pain/adjuvant medication burden. Although healthcare costs increased in both groups, there were no statistically significant differences in direct healthcare costs between the two groups.