Medicare Drug Benefits and High Cost Medications: Antipsychotics Under Part D

描述（由申请人提供）：2006年，医疗保险推出了D部分门诊处方药福利，这可能对需要长期和高成本药物治疗的患者产生重大影响，如抗精神病药物。医疗保险为抗精神病药物提供处方保护;然而，这些药物受到许多D部分计划中包含的潜在大量和复杂的成本分摊要求的影响，例如基于支出的覆盖范围缺口。一般来说，覆盖范围限制与必要药物使用的减少，不良临床事件的增加以及抵消药房成本节省的医疗成本增加有关;然而，缺乏证据表明D部分福利政策对处方抗精神病药物的患者的影响。本研究将检查D部分覆盖范围对1）药物使用和依从性的影响; 2）不良临床事件，包括急诊室就诊，住院和死亡; 3）医疗支出，包括自付药物支出，药房，门诊，住院和总医疗费用。研究人群包括接受抗精神病药物的受益人（2007年n= 43，217），他们参加了2004-2010年由两个大型D部分赞助商提供的Medicare Advantage处方药计划。它包括在差距期间费用分摊水平不同的计划、领取低收入补贴的受益人（样本的37%）和雇主赞助保险的受益人，其福利不包括差距或随时间变化以控制长期趋势。我们将比较D部分费用分摊较高和较低的受益人（例如，基本差距与无差距），以及审查低收入费用分摊补贴的影响。研究期包括D部分前两年（2004-2005年）和D部分后五年（2006-2010年）。我们将使用固定效应（条件）估计方法来检查与D部分费用分摊水平相关的年度结果变化，以及与覆盖缺口相关的年内时间变化（例如，在到达差距之前和之后）。根据药物类别定义研究队列与医疗保险制定国家处方集政策的水平一致;然而，由于我们预计费用分摊的影响会因抗精神病药物使用的临床适当性和治疗替代品的可用性而异，因此我们将评估精神病诊断的变化。我们将使用Medicare处方药事件档案，以及计划成员资格、临床就诊和药房数据，针对相关的人口统计、临床和计划特征进行调整。这项研究提供了一个独特的机会，将D部分药物的使用与临床事件和医疗支出数据联系起来，这些数据来自于一个大型的、定义明确的医疗保险受益人人群，他们接受了抗精神病药物治疗。研究结果可能会为该计划的改进提供信息，例如需要特定的费用分摊豁免（例如，以价值为基础的福利设计），完全或部分填补覆盖面缺口，或有针对性地扩大补贴，以减少意外后果并提高D部分对使用抗精神病药物的受益人的价值。

DESCRIPTION (provided by applicant): In 2006, Medicare introduced Part D outpatient prescription drug benefits, which could have significant implications for patients requiring chronic and high cost drug therapy, such as antipsychotics. Medicare provides formulary protection for antipsychotics; however, these drugs are subject to potentially substantial and complex cost-sharing requirements included in many Part D plans, such as spending-based coverage gaps. In general, coverage limits have been associated with decreases in necessary drug use, increases in adverse clinical events, and increases in medical costs that offset pharmacy cost savings; however, there is a dearth of evidence on the effects of Part D benefit policies on patients prescribed antipsychotics. This study will examine the impact of Part D coverage on 1) drug use and adherence; 2) adverse clinical events, including emergency department visits, hospitalizations and death; and 3) medical spending, including out-of-pocket drug spending, and pharmacy, outpatient, inpatient, and total medical costs. The study population includes beneficiaries receiving antipsychotics (n=43,217 in 2007) who are enrolled in Medicare Advantage Prescription Drug plans offered by two large Part D sponsors, 2004-2010. It includes plans that vary in cost-sharing levels during the gap, beneficiaries receiving low income subsidies (37% of the sample), and beneficiaries with employer- sponsored insurance, whose benefits do not include a gap or change over time to control for secular trends. We will compare beneficiaries with higher versus lower Part D cost-sharing (e.g., basic gap vs. no gap), as well as examine the impact of low income cost-sharing subsidies. The study period includes two years pre-Part D, 2004-2005, and five years post-Part D, 2006-2010. We will use fixed-effects (conditional) estimation methods to examine changes in annual outcomes associated with Part D cost-sharing levels, as well as within-year, temporal changes associated with the coverage gap (e.g., before and after the reaching the gap). Defining the study cohort based on drug class is consistent with the level at which Medicare has made national formulary policy; however, because we expect the impact of cost-sharing to vary by the clinical appropriateness of antipsychotic use and the availability of treatment alternatives, we will assess variations by psychiatric diagnosis. We will adjust for relevant demographic, clinical, and plan characteristics using Medicare Prescription Drug Event files, as well as plan membership, clinical encounter, and pharmacy data. This study provides a unique opportunity to link Part D drug utilization with clinical event and medical spending data for a large, well-defined population of Medicare beneficiaries prescribed antipsychotic drug therapy. The study findings may inform improvements to the program, such as the need for specific cost-sharing exemptions (e.g., value-based benefit designs), completely or partially filling in the coverage gap, or targeted subsidy expansions, to reduce unintended consequences and improve the value of Part D for beneficiaries using antipsychotics.