Division of Health Policy and Management, School of Public Health, University of Minnesota, Minneapolis, MN, USA.
Department of Health Policy, Vanderbilt University School of Medicine, Nashville, TN, USA.
J Natl Cancer Inst. 2022 Jul 11;114(7):1029-1035. doi: 10.1093/jnci/djac062.
Adherence to aromatase inhibitors (AIs) and tamoxifen has considerable survival benefits for postmenopausal women diagnosed with hormone receptor-positive breast cancer. Reduced out-of-pocket costs and treatment-related side effects could increase therapy adherence. Given that individuals' side effect profiles could differ across AIs, generic AI entry could facilitate switching between AIs to manage side effects and improve adherence.
From Surveillance, Epidemiology, and End Results-Medicare, we selected women first diagnosed with hormone receptor-positive breast cancer at age 65+ years and initiated an AI within 1 year of diagnosis between January 1, 2007, and May 31, 2008, or June 1, 2011, and December 31, 2012, and followed them for up to 2 years (N = 20 677). We estimated changes in probabilities of adherence with and without switching for Part D enrollees with and without the low-income subsidy (LIS vs non-LIS) before and after generic entry using linear probability models. Tests of statistical significance are 2-sided.
After generic entry reduced out-of-pocket costs of AIs (larger reduction for non-LIS), the percentage of women who ever switched from one AI to another AI increased from 8.8% to 14.6% for non-LIS and from 7.3% to 12.5% for LIS. Adherence without switching increased by 8.0 percentage points (pp) for non-LIS (P < .001) but decreased by 4.9 pp (P < .001) for LIS. Adherence with switching increased for both non-LIS (6.4 pp, P < .001) and LIS (4.4 pp, P < .001).
Increased switching after generic entry contributed to increased adherence, suggesting switching allowed better management of treatment-related side effects. Subsidized women also experienced increased adherence with switching after generic entry, suggesting that patients and physicians might not understand Part D benefit design when making decisions.
对于绝经后被诊断患有激素受体阳性乳腺癌的女性，服用芳香化酶抑制剂（AIs）和他莫昔芬可显著延长生存期。减少自付费用和治疗相关的副作用可能会提高治疗的依从性。鉴于个体的副作用谱可能因 AIs 而不同，通用 AI 的引入可能有助于在管理副作用和提高依从性方面在 AIs 之间进行转换。
我们从监测、流行病学和最终结果-医疗保险中选择了年龄在 65 岁及以上且在诊断后 1 年内（2007 年 1 月 1 日至 2008 年 5 月 31 日或 2011 年 6 月 1 日至 2012 年 12 月 31 日）开始使用 AI 的激素受体阳性乳腺癌首次确诊的女性，并对她们进行了长达 2 年的随访（N=20677）。我们使用线性概率模型估计了在通用 AI 上市前后，有（无）低收入补贴（LIS）的 Part D 参保者（LIS 与非 LIS）的 AI 治疗的依从性（无转换）和（有转换）的概率变化。统计显著性检验为双侧检验。
通用 AI 上市降低了 AIs 的自付费用（非 LIS 降低幅度更大）后，非 LIS 女性从一种 AI 转换为另一种 AI 的比例从 8.8%增加到 14.6%，LIS 女性从 7.3%增加到 12.5%。非 LIS 患者的无转换依从性增加了 8.0 个百分点（P<0.001），而 LIS 患者的无转换依从性则降低了 4.9 个百分点（P<0.001）。非 LIS 患者的有转换依从性增加了 6.4 个百分点（P<0.001），LIS 患者的有转换依从性增加了 4.4 个百分点（P<0.001）。
通用 AI 上市后转换的增加有助于提高依从性，这表明转换有助于更好地管理治疗相关的副作用。在通用 AI 上市后，接受补贴的女性在转换后也提高了依从性，这表明在做出决策时，患者和医生可能并不了解 Part D 福利设计。
