Outcomes Research in Review

Prescription Drug Benefits and Survival in Myeloma Among Medicare Beneficiaries

Olszewski AJ, Dusetzina SB, Trivedi AN, Davidoff AJ. Prescription drug coverage and outcomes of myeloma therapy among Medicare beneficiaries. J Clin Oncol. 2018;36(28):2879-2886.



Study Overview

Objective. To investigate the relationship between prescription drug coverage, receipt of active myeloma therapy, and overall survival (OS) among Medicare beneficiaries with multiple myeloma.

Design. Case-control and retrospective cohort archival data research.

Setting and participants. Authors examined SEER-Medicare registry and extracted patients with histologically confirmed multiple myeloma diagnosed in the period 2006 to 2011. Availability of complete Medicare part A/B claims from 1 year before diagnosis until December 2013 was required for analysis. Patients with Medicare advantage or managed care plans did not have claims data available and hence were excluded. Beneficiaries with a diagnosis of diffuse large B-cell lymphoma (DLBCL), who typically receive parenteral drugs for lymphoma therapy, were used as a control cohort.

Main outcome measures. Association between prescription drug coverage status and OS was the primary outcome measure of interest. Authors reported 3-year restricted survival time (RMST) ratios to compare OS among the beneficiaries with different prescription drug coverages. Receipt of active myeloma therapy among beneficiaries was also studied. Relative risk, adjusting for patient and disease-related characteristics, was reported to examine receipt of active myeloma therapy.

Results. Records of 9755 Medicare beneficiaries were evaluated. Of these, 1460 (15%) had no prescription coverage at diagnosis, 3283 (34%) had part D plan prescription benefits, 3607 (37%) had sponsored prescription coverage through an employer, federal employer, or veterans plan, and 1405 (14%) had a Medicaid prescription plan. Beneficiaries without coverage had fewer comorbidities, including anemia, neuropathy, or renal disease, than those with part D prescription coverage or Medicaid. Of those without any prescription drug coverage, 41% obtained prescription plan coverage after diagnosis of myeloma by the following January. Conversely, only 19% of patients with DLBCL and no coverage obtained a prescription plan.

Patients with myeloma were followed for 4.9 years and median survival was 2.3 years, with a 3-year OS rate of 43.1% (95% confidence interval [CI], 42.1%-44.1%). Relative to the group without coverage, survival was 16% longer in the Medicare part D group and sponsored plan group (RMST 1.16; 95% CI, 1.12-1.21). Medicaid/Medicare dual beneficiaries had worse OS in both myeloma and DLBCL consistent with poor performance status and unfavorable baseline comorbidities. However, among patients with myeloma, Medicaid/Medicare dual beneficiaries had better survival (RMST 1.08; 95% CI, 1.03-1.13) compared to the group without coverage. There was no difference in OS for those with or without prescription drug coverage in the DLBCL cohort.

There were significant differences in treatment of myeloma based on types of prescription drug coverage. Due to increasing use of bortezomib following its approval by the U.S. Food and Drug Administration (FDA), parenteral chemotherapy use doubled from 24% to 48% from 2006 to 2011, and utility of active myeloma care increased from 88% to 91%. Medicare part D plan enrollees were 6% more likely to receive active myeloma care, and both Medicaid group and sponsored plan group beneficiaries were equally likely to receive active myeloma care compared to beneficiaries without prescription coverage. Medicaid enrollees were less likely to receive parenteral therapy.


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