Drug Cost Containment Changes and Quality of Care for Mentally Ill Dual Enrollees

描述（由申请人提供）：残疾，低收入的美国人同时获得医疗补助和医疗保险（即双重投保人），是医疗保险人口中增长最快的部分之一。这些受益人中约有三分之一（约250万人）患有昂贵且常常使人衰弱的精神疾病，包括精神分裂症和双相情感障碍。在这些双入选者中，较差的药物治疗依从性导致更差的健康状况和昂贵的下游临床事件，包括因严重精神疾病（SMI）住院治疗。2003年的《医疗保险现代化法案》（MMA）于2006年1月1日将双重参保者门诊处方药保险的责任从各州医疗补助计划转移到由医疗保险计划资助的私人D部分计划。医疗保险和医疗补助服务中心（CMS）随机分配双受益人D部分处方药计划（pdp）相对较低的保费。这些独立的pdp可以在计划处方中包含的处方药的数量和类型上有所不同，并且可以对任何药物处方采用诸如事先授权（PA）之类的使用管理方法。由于每个州都确定了自己的医疗补助覆盖政策，双重受益人在过渡到D部分覆盖之前面临一系列药物覆盖福利。例如，在15个州，双重参保者对处方数量有上限。因此，2006年向D部分的过渡扩大了其药品覆盖范围，并消除了造成代价高昂的不良健康事件的潜在风险因素。然而，大多数州将抗精神病药和抗惊厥药排除在医疗补助事先授权（PA）之外，而pdp通常将PA作为管理药物成本的主要方法。因此，随着药物覆盖责任从国家转移到私人计划，双重登记受益人在获得门诊处方药方面面临较少的国家决定的成本障碍，但在获得精神药物方面可能面临更多的计划决定的行政障碍。我们将在四个地理上不同的大州分别分析D部分的影响：两个州对处方数量设置了上限，并且在2004年至2007年间的共同支付额相对较高（南卡罗来纳州：每月限制4张处方；加利福尼亚州：每月限制6张），另外两个州在同一时期没有上限，共同支付额相对较低（密苏里州，新泽西州）。在目标1中，我们将使用强准实验设计，多重中断时间序列，来检验这种转变对人口水平的影响：(1)精神科药物使用的患病率和持久性；(2)使用非药物精神科服务；(3)成本。在目标2中，我们在患者水平上使用随机设计来估计覆盖限制对精神科药物使用（包括停药和转换药物）、精神科门诊和急诊室就诊以及成本的影响。在Aim 3中，我们将使用这两种设计来检查政策变化对精神分裂症和双相情感障碍患者的高危亚组（由躯体合并症和少数民族状态定义）的影响。

DESCRIPTION (provided by the applicant): Disabled, low income Americans who receive both Medicaid and Medicare insurance coverage (i.e., dual enrollees), represent one of the fastest growing segments of the Medicare population. About one-third of these beneficiaries (est. 2.5 million) have expensive, often debilitating mental illness, including schizophrenia and bipolar disorder. Poor drug treatment adherence among these dual enrollees leads to worse health and expensive downstream clinical events including hospitalizations for severe mental illness (SMI). The Medicare Modernization Act of 2003 (MMA) transferred the responsibility for outpatient prescription drug coverage for dual enrollees from individual state Medicaid programs to private Part D plans funded by the Medicare program on January 1, 2006. The Centers for Medicare and Medicaid Services (CMS) randomly assigns dual beneficiaries to Part D Prescription Drug Plans (PDPs) with relatively low premiums. These standalone PDPs can vary in the numbers and types of prescription drugs included in the plan formulary and can employ utilization management approaches such as prior authorization (PA) for any drug prescriptions. Because each state determined its own Medicaid coverage policies, dual beneficiaries faced a range of drug coverage benefits prior to their transition to Part D coverage. For example, in 15 states, dual enrollees had caps on the number of prescriptions. Thus, the transition to Part D in 2006 expanded their drug coverage and removed a potential risk factor for costly adverse health events. Most states, however, excluded antipsychotic and anticonvulsant therapy from Medicaid prior authorization (PA), while PDPs often use PA as the primary approach for managing drug costs. Thus, as drug coverage responsibility shifts from states to private plans, dually enrolled beneficiaries face fewer state-determined cost barriers to outpatient prescription drug access, but potentially more plan-determined administrative barriers to psychotropic drug access. We will analyze the impact of Part D separately in four large and geographically diverse states: two that placed caps on the number of prescriptions and had relatively higher copayments between 2004 and 2007 (South Carolina: limit of 4 prescriptions per month; California: limit of 6 per month), and two that had no caps and relatively lower copayments during the same period (Missouri, New Jersey). In Aim 1, we will use a strong quasi-experimental design, Multiple Interrupted Time Series, to examine the population level impacts of this transition on: (1) the prevalence and persistence of psychiatric medication use; (2) use of non-drug psychiatric services; and (3) costs. In Aim 2 we use a randomized design at the patient level to estimate the effect of coverage restrictions on use of psychiatric medications (including discontinuation and switching of medications), psychiatric outpatient and ER visits, and costs. In Aim 3 we will use both designs to examine the impact of the policy changes among at-risk subgroups (defined by somatic comorbidities and minority status) of patients with schizophrenia and bipolar disorder.