1020 — Which Veterans Were Most Adversely Impacted by the VA Medication Copayment Increase?

Maciejewski ML (Durham HSR&D), Bryson CL (Seattle HSR&D), Perkins M (Seattle HSR&D), Sharp N (Seattle HSR&D), Liu CF (Seattle HSR&D)

Objectives:
Prior VA and non-VA studies have shown that medication copayments reduce adherence, but few studies have examined which subgroups are most adversely impacted by increased medication copayments. VA increased the copayment for medications from $2 to $7 per 30 days of fill in February 2002. The purpose of this study is to examine whether cost-related medication non-adherence differs between high-risk and low-risk veterans and between veterans on zero or one medication versus taking two or more other medications.

Methods:
Using a sample of 2,465 veterans with diabetes taking oral hypoglycemic agents (OHAs) and 7,731 veterans with hypertension taking anti-hypertensive medications, we stratified the samples by Diagnostic Cost Group (DCG) risk score (< 1, > 1) and by the number of medications that veterans were taking in the twelve months before baseline (< 2, > 2). We used generalized estimating equations to examine differences in pre- and post-copay changes in adherence to OHAs and anti-hypertensives between veterans exempt from copays and veterans required to pay. We controlled for age, gender, race, marital status, VA site, Census-based per capita income and education attainment in the veteran’s zip code of residence, and time trends.

Results:
Among low-risk veterans, veterans required copayments had a greater decline after the copay increase than copay exempt veterans (p=0.006). High-risk veterans in both copay groups had similar adherence between pre and post periods. Veterans taking few (< 2) medications at baseline were similarly adherent regardless of copay status. Among veterans taking two or more medications at baseline, those required copayments had a greater decrease in adherence after the copay increase (p=0.01), compared to copay-exempt veterans.

Implications:
The 2002 medication copayment increase from $2.00 to $7.00 for a 30-day fill was associated with the greatest cost-related medication non-adherence in veterans with diabetes or hypertension taking multiple medications and those with little comorbidity.

Impacts:
VA policymakers need to evaluate whether the revenue benefits of increased medication copayments are offset by cost-related medication non-adherence by veterans with diabetes or hypertension taking essential medications. VA providers may need to track more closely veterans who report cost-related medication non-adherence to maintain disease control.