title: Association Between Out-Of-Pocket Costs, Race/Ethnicity, and Adjuvant Endocrine Therapy Adherence Among Medicare Patients With Breast Cancer.
abstract: Purpose Previous studies suggest that adherence to adjuvant endocrine therapy (AET) for patients with breast cancer is suboptimal, especially among minorities, and is associated with out-of-pocket medication costs. This study aimed to determine whether there are racial/ethnic differences in 1-year adherence to AET and whether out-of-pocket costs explain the racial/ethnic disparities in adherence. Methods This retrospective cohort study used the SEER-Medicare linked database to identify patients ≥ 65 years of age with hormone receptor-positive breast cancer who were enrolled in Medicare Part D from 2007 to 2009. The cohort included non-Hispanic whites, blacks, Hispanics, and Asians. Out-of-pocket costs for AET medications were standardized for a 30-day supply. Adherence to tamoxifen, aromatase inhibitors (AIs), and overall AET (tamoxifen or AIs) was assessed using the medication possession ratio (≥ 80%) during the 12-month period. Results Of 8,688 patients, 3,197 (36.8%) were nonadherent to AET. Out-of-pocket costs for AET medication were associated with lower adjusted odds of adherence for all four cost categories compared with the lowest category of ≤ $2.65 ( P < .01). In the univariable analysis, Hispanics had higher odds of adherence to any AET at initiation (OR, 1.30; 95% CI, 1.07 to 1.57), and blacks had higher odds of adherence to AIs at initiation (OR, 1.27; 95% CI, 1.04 to 1.54) compared with non-Hispanic whites. After adjusting for copayments, poverty status, and comorbidities, the association was no longer significant for Hispanics (OR, 0.95; 95% CI, 0.78 to 1.17) or blacks (OR, 0.96; 95% CI, 0.77 to 1.19). Blacks had significantly lower adjusted odds of adherence than non-Hispanic whites when they initiated AET therapy with tamoxifen (OR, 0.54; 95% CI, 0.31 to 0.93) after adjusting for socioeconomic, clinic, and prognostic factors. Conclusion Racial/ethnic disparities in AET adherence were largely explained by women's differences in socioeconomic status and out-of-pocket medication costs.
authors.affiliation: All authors: The University of Texas Health Science Center at Houston, Houston, TX.
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Farias
authors.affiliation: All authors: The University of Texas Health Science Center at Houston, Houston, TX.
authors.forename: Xianglin L
authors.initials: XL
authors.lastname: Du
mesh_terms: D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000191:economics / Q000627:therapeutic use*; D047072:Aromatase Inhibitors / Q000191:economics / Q000627:therapeutic use; D001213:Asian / Q000706:statistics & numerical data; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000601:surgery; D017024:Chemotherapy, Adjuvant / Q000191:economics; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D005102:Health Expenditures / Q000706:statistics & numerical data*; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D006278:Medicare / Q000706:statistics & numerical data; D055118:Medication Adherence / Q000208:ethnology; D012189:Retrospective Studies; D018426:SEER Program / Q000706:statistics & numerical data; D012959:Socioeconomic Factors; D013629:Tamoxifen / Q000191:economics / Q000627:therapeutic use; D014481:United States; D044465:White People / Q000706:statistics & numerical data; D016903:Drug Monitoring
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D013629:Tamoxifen