Specialty Tier-Level Cost Sharing and Biologic Agent Use in the Medicare Part D Initial Coverage Period Among...

Area of Science:

• Rheumatology
• Health Economics
• Health Services Research

Background:

• Rheumatoid arthritis (RA) treatment often involves costly biologic agents.
• Medicare Part D's specialty tier cost-sharing can significantly impact patient out-of-pocket expenses.
• Understanding the effect of cost-sharing on biologic agent utilization is crucial for patient adherence and outcomes.

Purpose of the Study:

• To investigate the association between specialty tier cost-sharing and the use of biologic agents for rheumatoid arthritis (RA).
• To compare RA patients facing high out-of-pocket costs with those having low-income subsidies in Medicare Part D.
• To analyze treatment patterns, including biologic agent use and treatment gaps, during the initial coverage period (ICP).

Main Methods:

• Retrospective analysis of 2007-2010 Medicare 5% sample files.
• Comparison of RA patients without low-income subsidies (non-LIS group) to those with low-income subsidies (LIS group).
• Logistic regression models used to estimate risk-adjusted outcomes, controlling for patient and plan characteristics.

Main Results:

• Non-LIS patients faced significantly higher out-of-pocket costs for biologic agents ($484 vs. $5).
• Non-LIS patients were less likely to fill Part D biologic agents (61.2% vs. 72.7%) and any biologic agent (70.1% vs. 76.9%).
• Non-LIS patients were more likely to use Part B biologic agents (9.9% vs. 4.4%) and experienced longer treatment gaps.

Conclusions:

• Specialty tier cost-sharing in Medicare Part D is associated with reduced biologic agent use and treatment interruptions in RA patients.
• Financial barriers significantly influence treatment adherence for RA biologic agents.
• Policy interventions may be needed to mitigate cost-related non-adherence for RA patients in Medicare Part D.