Does the association between prescription copayment increases and medication adherence differ by race?

Area of Science:

• Health Services Research
• Health Economics
• Pharmacoeconomics

Background:

• Previous research indicates prescription copayment increases negatively affect medication adherence.
• Studies have not thoroughly examined racial disparities in the impact of copayment increases on adherence.

Purpose of the Study:

• To investigate whether the association between prescription copayment increases and medication adherence differs by race.
• To analyze the impact of a specific copayment increase on adherence to diabetes and hypertension medications in White and Black veterans.

Main Methods:

• Utilized Veterans Affairs (VA) administrative data to analyze medication adherence.
• Employed a difference-in-difference approach to compare adherence changes before and after a copayment increase ($2 to $7).
• Compared adherence trends between White and Black veterans, considering copayment exemption status.

Main Results:

• A copayment increase led to decreased medication adherence for both White and Black veterans.
• The reduction in adherence was statistically similar between White and Black veterans.
• No significant racial differences were found in the adherence impact of the copayment increase.

Conclusions:

• Copayment increases affect medication adherence similarly across major racial groups in the VA system.
• Despite potential minority patient barriers, copayment policy impacts on adherence appear equitable in this context.
• Findings suggest copayment policies may have a uniform effect on adherence regardless of race within the VA.