Mechanisms of Intervention Impact for Diverse Dementia Caregiving Populations

说明(申请人提供)：老年人口的预计增长以及对阿尔茨海默病和类似痴呆症的早期识别的更加重视，对医疗保健系统提出了巨大的要求，包括向痴呆症患者提供某种持续非正式护理的1,500多万家庭成员。相当多的研究记录了痴呆症护理的主要和次要压力来源，并提供循证服务以减轻与护理相关的负担和压力仍然是主要的公共卫生优先事项。由于家庭照顾者是一个非常多样化的群体，他们在许多人口统计和情景变量上存在差异，因此需要进行仔细和复杂的分析，以更好地了解现有干预试验在不同亚群中取得效果的机制。在这份提案中，我们描述了一系列将对第二资源加强阿尔茨海默氏症照顾者健康(REACH II)项目公开可用的数据进行的二次分析。REACH II在现有的照顾者干预随机试验中是独一无二的，它纳入了地理和种族多样化的样本，但到目前为止，只有少数出版物检查了干预结果的影响，没有发表的分析检查了干预影响的中介因素，或测试了这些机制是否因种族或其他重要的人口统计亚组(例如，性别、配偶和非配偶照料者)而不同。我们提出了一系列协调一致的分析，以解决四个相互关联的目标。特别是，我们建议1)对用于评估REACH II结果的常用工具进行项目级心理测量学分析，包括差异项目功能(DIF)分析，以确定人口亚组中的一些结果是否可能部分受到测量偏差的影响；2)对干预可能实现主要结果好处(减少照顾者的抑郁和负担)的潜在机制(改善的社会支持，减少的压力评估)进行中介分析；3)进行多组结构方程建模分析，以确定目标2的中介效应和先前发表的调节效应是否随种族或民族而变化；4)检验REACH II干预措施依从性的预测因素，并对充分遵守REACH II干预措施的受试者子集的干预效果进行编译平均因果效应(CACE)分析。这些分析将为REACH II干预措施的潜在人口影响提供大量信息，并有助于指导特定痴呆症护理亚群的额外翻译工作。

DESCRIPTION (provided by applicant): The projected growth of the older adult population and the greater emphasis on early stage identification of Alzheimer's disease and similar dementias are placing heavy demands on the health care system, including the more than 15 million family members who provide some type of ongoing informal care to persons with dementia. A considerable body of research documents the primary and secondary stressors of dementia caregiving, and providing evidence-based services to ease the burden and stress associated with caregiving continues to be a major public health priority. Because family caregivers are an incredibly diverse group who differ along many demographic and situational variables, careful and sophisticated analyses are needed to better understand the mechanisms by which existing intervention trials have achieved their effects among diverse subgroups. In this proposal, we describe a series of secondary analyses to be conducted on the publically-available data from the second Resources for Enhancing Alzheimer's Caregivers Health (REACH II) project. REACH II was unique among the existing randomized trials of caregiver interventions in its enrollment of a geographically and racially diverse sample, but only a few publications to date have examined intervention outcome effects, and no published analyses have examined the mediators of intervention impact or tested whether such mechanisms differ by race or by other important demographic subgroups (e.g., gender, spouse vs. non-spouse caregivers). We propose a coordinated series of analyses that will address four inter-related aims. In particular, we propose 1) to conduct item-level psychometric analyses of the common instruments used to assess REACH II outcomes, including differential item functioning (DIF) analyses, to determine if some findings across demographic subgroups might be partially contaminated by measurement biases; 2) to perform mediation analyses of the potential mechanisms (improved social support, reduced stress appraisals) by which the intervention may have achieved primary outcome benefits (reduced caregiver depression and burden); 3) to conduct multiple group structural equation modeling analyses that will determine if the mediation effects from aim 2 and previously published moderator effects vary as a function of race or ethnicity; and 4) to examine the predictors of compliance with the REACH II intervention and conduct complier-average causal effect (CACE) analyses of the effect of the intervention among the subset of participants who sufficiently complied with it. These analyses will substantially inform the potential population impact of the REACH II intervention and be useful for guiding additional translational work for particular dementia caregiving subgroups.