Geographic Variation of Adjuvant Breast Cancer Therapy Initiation in the United States: Lessons From Medicare Part D. J Natl Compr Canc Netw 2017 Dec;15(12):1509-1517
Date
12/11/2017Pubmed ID
29223989DOI
10.6004/jnccn.2017.7021Scopus ID
2-s2.0-85038431887 (requires institutional sign-in at Scopus site) 2 CitationsAbstract
Background: Drug utilization under Medicare Part D varies significantly by geographic region. This study examined the extent to which geographic variation in Part D plan characteristics contributes to the variation in choice of initial endocrine therapy agent among women with incident breast cancer. Methods: Two-stage multivariate regression analyses were applied to the 16,541 women identified from Medicare claims as having incident breast cancer in 2006-2007. The first stage determined the effect of state of residence on the probability of having an aromatase inhibitor (AI), as opposed to tamoxifen, as initial endocrine therapy. The second stage provided estimates of the impact of state-specific Part D plan characteristics on variation in choice of initial therapy. Results: There was substantial residual geographic variation in the likelihood of using an AI as initial endocrine therapy, despite controlling for socioeconomic status, breast cancer treatment, and other factors. Regression-adjusted probabilities of starting an AI ranged from 57.3% in Wyoming to 92.6% in the District of Columbia. Results from the second stage revealed that variation in characteristics of Part D plans across states explained approximately one-third (30%) of the state-level variability in endocrine therapy. A higher number of plans with cost-sharing above the mean, greater spread in deductibles, and a greater spread in monthly drug premiums were associated with lower adjusted state probabilities of initiating an AI. In contrast, a higher number of drug plans with monthly premiums above the state mean and higher mean cost-sharing (in dollars) were both positively associated with likelihood of starting on an AI. Conclusions: Study findings suggest that variation in benefit design of Part D plans accounts for an important share of the large and persisting variability in use of AIs-the preferred oral therapy for breast cancer.
Author List
Charlson JA, McGinley EL, Nattinger AB, Neuner JM, Pezzin LEAuthors
John A. Charlson MD Associate Professor in the Medicine department at Medical College of WisconsinAnn B. Nattinger MD, MPH Associate Provost, Professor in the Medicine department at Medical College of Wisconsin
Joan Neuner MD, MPH Professor in the Medicine department at Medical College of Wisconsin
Liliana Pezzin PhD, JD Professor in the Institute for Health and Equity department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AgedAged, 80 and over
Antineoplastic Agents, Hormonal
Aromatase Inhibitors
Breast Neoplasms
Endocrine System
Female
Humans
Medicare Part D
Tamoxifen
United States
