Outcomes of beta blockers after myocardial infarction in nursing home residents

描述（由申请人提供）：背景：心肌梗死（心脏病发作）后使用β受体阻滞剂进行二级预防得到了许多非卧床人群的可靠证据基础的支持。然而，几乎没有关于β受体阻滞剂在老年疗养院患者中的结果的数据，这些患者可能特别容易受到β受体阻滞剂的不良事件的影响，并且从这些药物中获益较少。目的：（1）描述老年疗养院患者心肌梗死后使用β受体阻滞剂的模式和预测因素;（2和3）确定β受体阻滞剂对该人群功能结局、再住院和死亡的影响。研究方法：使用结合临床和管理数据的观察性研究设计，研究人群将包括2007年5月至2010年3月期间因心肌梗死住院且在此事件之前未使用β受体阻滞剂的大型全国连锁养老院的长期居民。将在出院后对受试者进行6至32个月的结局随访，比较在指数住院后开始和未开始β受体阻滞剂治疗的受试者。本研究的数据将来自（1）最小数据集，一个标准化临床评估数据的综合数据库，由临床医生定期为美国几乎所有的疗养院居民完成;（2）医疗保险A部分的住院诊断和服务索赔数据;以及（3）来自Medicare Part D和来自私人疗养院连锁（Manor Care）的药物使用数据，其捕获在Part D的索赔数据不可用的时期内的药物使用。将采用倾向评分方法和其他因果推断方法来控制β受体阻滞剂使用与关注结局之间关系的潜在混杂因素。认识到没有一种方法可以最终解决所有潜在的混杂因素，将使用相关方法的一系列估计值来收敛于有临床意义的效应量范围。为了进一步检验和交叉验证结果，将在另外两个队列中重复分析。首先，将对全国范围内所有从医院返回疗养院的医疗保险患者的结果进行分析，这些患者没有经过急性后康复的中间期（医疗保险D部分不可见的时期）。其次，将对VA疗养院的患者进行重复分析。VA数据包含Medicare无法提供的其他元素，允许测试建模假设和潜在偏倚，可用于完善主要队列的分析。相关性/公共卫生意义：更好地了解β受体阻滞剂在心肌梗死后虚弱的疗养院居民中的益处和危害，将大大改善证据基础，并有助于指导这一重要人群的治疗决策。

DESCRIPTION (provided by applicant): Background: The use of beta blockers for secondary prevention after myocardial infarction (heart attack) is supported by a solid evidence base for many ambulatory populations. However, virtually no data exist on outcomes of beta blockers in older nursing home patients, who may be particularly susceptible to adverse events from beta blockers and yield less benefit from these drugs. Aims: (1) To describe patterns and predictors of beta blocker use in older nursing home patients after myocardial infarction; and (2 and 3) to determine the impact of beta blockers on functional outcomes, rehospitalization, and death in this population. Methods: Using an observational study design that combines clinical and administrative data, the study population will comprise long-term residents in a large, national nursing home chain who were hospitalized for myocardial infarction between May 2007 and March 2010 and had not been using beta blockers prior to this event. Subjects will be followed for outcomes for 6 to 32 months after hospital discharge, comparing those who were and were not started on beta blockers after the index hospitalization. Data for this study will come from (1 the Minimum Data Set, a comprehensive database of standardized clinical assessment data that is completed at regular intervals by clinicians for nearly all nursing home residents in the United States; (2) claims data on inpatient diagnoses and services from Medicare Part A; and (3) drug utilization data from Medicare Part D and from a private nursing home chain (Manor Care), which captures drug use during periods where claims data from Part D are unavailable. Propensity score approaches and other causal inference methods will be employed to control for potential confounding in the relationship between beta blocker use and the outcomes of interest. Recognizing that no single approach can conclusively address all potential confounders, a series of estimates from related approaches will be used to converge on a clinically meaningful range of effect sizes. To further test and cross-validate results, the analyses will be repeated in two other cohorts. First, results will be analyzed for all Medicare patients nationwide who returned from hospital to nursing home without an intermediary period of post-acute rehabilitation (the period invisible to Medicare Part D). Second, analyses will be repeated for patients in VA nursing homes. VA data contain additional elements not available through Medicare, allowing testing of modeling assumptions and potential biases that can be used to refine analyses in the primary cohort. Relevance / public health significance: Better understanding the benefits and harms of beta blockers in frail nursing home residents after myocardial infarction will substantially improve the evidence base and help guide treatment decisions for this important population.