COGNITIVE AND PHYSICAL BASIS OF DISABLEMENT

这项研究将测试“残疾”的因果模型，在该模型中，损伤(运动或认知能力测试的低分)和功能限制(日常任务的低效或不安全执行)导致残疾(承认日常生活中的工具性和基本活动方面的困难或需要帮助[IADL/BADL])。我们将追踪从华盛顿高地-因伍德哥伦比亚老龄化项目(WHICAP)现有的多种族社区研究中招募的360名老年人，他们都将有轻度到中度的残疾，不符合痴呆症的标准。他们将被评估3次，相隔18个月。在残疾群体中(基于自我报告的1、2或3个领域)，一半的受试者认知正常，一半的受试者有轻微的认知障碍或可疑的痴呆症。我们将评估损伤和功能限制对残疾的直接和间接影响，这些群体由自我报告的残疾状况和认知表现定义，在不同的种族-民族(非洲裔美国人、西班牙裔美国人、白人)和纵向上。此外，我们将使用临床诊断(在临床共识会议上建立)作为黄金标准，或者通过使用不假定黄金标准的潜在类别模型来评估自我和代理残疾报告的准确性。这项研究的一个重要特点是它使用了运动和过程技能评估(AMPS)，这是一种对日常生活活动中的功能限制进行评级的职业评估工具。AMPS评估给出了影响IADL/BADL任务有效和安全执行的运动和认知/过程限制的分数。OT‘s将在受试者家庭中进行AMPS评估，以及对身体损伤的详细评估(以及家庭和邻里环境的测量)。家长WHICAP的研究将提供有关认知表现和神经医学状况的数据。我们的主要目标是测试致残的因果(结构方程)模型。我们假设，损伤与残疾直接相关，但也通过观察到的运动和认知/过程限制而间接相关。我们会测试这种间接影响对某些长者(例如轻度伤残人士)是否较其他组别为强。这一发现表明，残疾可以通过运动和认知/过程技能的补救以及努力减少损伤来减少。

This research will test a causal model of "disablement,"in which impairment (low scores on tests of motor or cognitive performance) and functional limitation (inefficient or unsafe performance of daily tasks) result in disability (recognition of difficulty or need for help in instrumental and basic activities of daily living [IADL/BADL]). We will follow 360 elders recruited from an existing multi-ethnic community-based study, the Washington Heights-Inwood Columbia Aging Project (WHICAP), all of whom will have mild-to-moderate disability and not meet criteria for dementia. They will be assessed 3 times, 18 months apart. Within disability groups (1, 2, or 3 domains based on self-reports), half of the subjects will be cognitively normal and half will have mild cognitive impairment or questionable dementia. We will assess the direct and indirect effects of impairment and functional limitation on disability in groups defined by self-reported disability status and cognitive performance, in different race-ethnic groups (African-American, Hispanic, white), and longitudinally. In addition, we will assess the accuracy of self- and proxy-reports of disability using a clinical diagnosis (established in a clinical consensus conference) as a gold standard, and alternatively through use of latent class models that do not assume a gold standard. An important feature of this research is its use of the assessment of Motor and Process Skills (AMPS) , an occupational assessment tool for rating functional limitation in the activities of daily living. AMPS evaluations yield scores for motor and cognitive/process limitations that interfere with efficient and safe performance of IADL/BADL tasks. OT's will conduct AMPS evaluations in subject homes, along with detailed assessments of physical impairment (as well as measures of home and neighborhood environment). The parent WHICAP study will provide data on cognitive performance and neurologic-medical status. Our major goal is to test a causal (structural equations) model of disablement. We hypothesize that impairment is related to disability directly but also indirectly through observed motor and cognitive/process limitations. We will test whether this indirect effect is stronger for some groups of elders (e.g., mild disabled) than others. This finding would suggest that disability may be reduced through remediation of motor and cognitive/process skills, as well as by efforts to reduce impairment.