Utilization and costs of cardiovascular disease medications in dialysis patients in Medicare Part D.

BACKGROUND

Cardiovascular disease (CVD) is a major source of mortality and morbidity in dialysis patients. Population-level descriptions of CVD medication use are lacking in this population.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS: Adult dialysis patients in the United States, alive on December 31, 2006, with Medicare Parts A and B and enrollment in Medicare Part D continuously in 2007.

PREDICTOR

CVDs and demographic characteristics.

OUTCOME

≥1 prescription fill during follow-up (2007).

MEASUREMENTS

Average out-of-pocket costs per user per month and average total drug costs per member per month were calculated.

RESULTS

Of 225,635 dialysis patients who met inclusion criteria during the entry period, 70% (n = 158,702) had continuous Part D coverage during follow-up. Of these, 76% received the low-income subsidy. β-Blockers were the most commonly used CVD medication (64%), followed by renin-angiotensin system inhibitors (52%), calcium channel blockers (51%), lipid-lowering agents (44%), and α-agonists (23%). Use varied by demographics, geographic region, and low-income subsidy status. For CVD medications, mean out-of-pocket costs per user per month were $3.44 and $49.59 and mean total costs per member per month were $124.02 and $110.32 for patients with and without the low-income subsidy, respectively.

LIMITATIONS

Information was available for only filled prescriptions under the Part D benefit; information for clinical contraindications was lacking, information for over-the-counter medications was unavailable, and medication adherence and persistence were not examined.

CONCLUSIONS

Most Medicare dialysis patients in 2007 were enrolled in Part D, and most enrollees received the low-income subsidy. β-Blockers were the most used CVD medication. Total costs of CVD medications were modestly higher for low-income subsidy patients, but out-of-pocket costs were much higher for patients not receiving the subsidy. Further study is warranted to delineate sources of variation in the use and costs of CVD medications across subgroups.