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

Abstract

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.

Keywords::

• Fibromyalgia
• Comorbidity
• Treatment patterns
• Pregabalin
• Duloxetine

Transparency

Declaration of funding

This research was funded by Pfizer Inc. All authors contributed to the concept design of the study and to data preparation and analysis. All authors drafted, reviewed, and revised the manuscript.

Declaration of financial/other relationships

Dr Gore is Principal Consultant and Kei-Sing Tai is Principal Statistician at Avalon Health Solutions, Inc., and they were paid consultants to Pfizer Inc in connection with the development and execution of both this article and the research it describes. Dr Gore also owns stock in Pfizer. Dr Zlateva and Ms Chandran are employees and stockholders in Pfizer. Dr Leslie was paid an honorarium by Avalon Health Solutions, Inc. for his participation in this research and for his review of and input for this article. Dr Leslie also has performed consulting for Kurron Bermuda Ltd.

Acknowledgments

The authors would like to thank Christopher Rice for editorial assistance in the preparation of this article. Christopher Rice is an employee of Avalon Health Solutions, Inc. Editorial support to prepare this manuscript for journal submission was provided by UBC Scientific Solutions and funded by Pfizer Inc.