Division of Health Policy & Management, School of Public Health, University of Minnesota, 420 Delaware St. S.E, Minneapolis, MN, 55455, USA.
Division of Health Policy & Management, School of Public Health, University of Minnesota, 420 Delaware St. S.E, Minneapolis, MN, 55455, USA.
Res Social Adm Pharm. 2021 Sep;17(9):1588-1595. doi: 10.1016/j.sapharm.2020.12.006. Epub 2020 Dec 16.
The trade-offs between innovation and pharmaceutical access are central to the policy debate on drug pricing. High prices may limit access, result in medication underuse, and negatively affect outcomes. Generic drugs make treatments more affordable. Prior research measured access as utilization without a defined population that should receive certain drugs, it is unknown whether generic entry reduces underuse and thus improves access.
To measure changes in access (use, timeliness) with the introduction of three generic aromatase inhibitors (AIs, oral breast cancer drugs) between June 2010 and June 2011.
This population-based study included 93,650 older (65+) women diagnosed with hormone receptor-positive breast cancer between 2007 and 2013 in the Surveillance, Epidemiology and End Results-Medicare linked database. We examined changes in access with generic entry for initiation of any adjuvant hormonal therapy drug (AIs or tamoxifen) within one year of diagnosis, time from diagnosis to initiation, and choice of initial therapy.
Among 93,650 newly diagnosed breast cancer cases, 67,372 initiated one of the four drugs. With generic entry, initiation rates increased from 69.5% to 74.3%, but non-initiation remained high (up to 25.7%). After controlling for demographics, clinical factors, and insurance coverage, the probability of initiation increased by 4.6 percentage points (P < 0.001, 95%CI: [4.1,5.2]) after generic entry. With generic entry, estimated time to initiation decreased by 0.3 months (P < 0.001, 95%CI: [0.2,0.3]) from 4.1 months, and the probability of choosing AIs over tamoxifen increased by 5.9 percentage points (P < 0.001, 95%CI: [5.3,6.5]). Patterns did not substantially differ by level of cost-sharing.
Generic entry of AIs was associated with increased probability of receiving recommended treatments, timeliness of treatment, and the probability of receiving clinically preferred treatments. Price changes with generic entry only partially explained these improvements. High non-initiation rates after generic entry suggest prices are not the sole determinant of access.
创新与药品可及性之间的权衡取舍是药品定价政策辩论的核心。高药价可能会限制可及性，导致药物使用不足，并对结果产生负面影响。仿制药可使治疗更加负担得起。先前的研究以未定义应接受特定药物的人群为基础来衡量药物可及性（即使用率），尚不清楚仿制药的进入是否会减少使用不足，从而改善药物可及性。
测量 2010 年 6 月至 2011 年 6 月期间三种新型芳香酶抑制剂（口服乳腺癌药物）上市后对可及性（用药、及时性）的影响。
这项基于人群的研究纳入了 2007 年至 2013 年间在监测、流行病学和最终结果-医疗保险链接数据库中诊断患有激素受体阳性乳腺癌的 93650 名 65 岁以上的女性。我们研究了在诊断后一年内开始使用任何辅助激素治疗药物（芳香酶抑制剂或他莫昔芬）时，随着仿制药的进入，可及性的变化情况，包括开始治疗的时间、从诊断到开始治疗的时间以及初始治疗选择。
在 93650 例新诊断的乳腺癌病例中，有 67372 例开始使用了这四种药物中的一种。随着仿制药的进入，起始率从 69.5%上升至 74.3%，但未起始率仍居高不下（高达 25.7%）。在控制人口统计学、临床因素和保险覆盖范围后，仿制药上市后，起始率增加了 4.6 个百分点（P<0.001，95%置信区间：[4.1，5.2]）。随着仿制药的进入，估计的起始时间从 4.1 个月减少了 0.3 个月（P<0.001，95%置信区间：[0.2，0.3]），选择芳香酶抑制剂的概率增加了 5.9 个百分点（P<0.001，95%置信区间：[5.3，6.5]）。这些模式在成本分担水平上没有显著差异。
芳香酶抑制剂的仿制药上市与提高接受推荐治疗的概率、治疗及时性以及接受临床首选治疗的概率有关。仿制药上市带来的价格变化部分解释了这些改善。仿制药上市后仍有较高的未起始治疗率，这表明价格并不是可及性的唯一决定因素。
