COGNITIVE AND PHYSICAL BASIS OF DISABLEMENT

这项研究将测试“残疾“的因果模型，其中损伤（运动或认知表现测试得分低）和功能限制（日常任务的低效或不安全表现）导致残疾（识别工具性和基本日常生活活动的困难或需要帮助[IADL/BADL]）。 我们将跟踪从现有的多种族社区研究中招募的360名老年人，即华盛顿高地-英伍德哥伦比亚老龄化项目（WHICAP），所有这些人都将有轻度至中度残疾，不符合痴呆症的标准。 他们将被评估3次，间隔18个月。 在残疾组（基于自我报告的1、2或3个领域）中，一半受试者的认知正常，一半受试者有轻度认知障碍或可疑痴呆。我们将评估损伤和功能限制对残疾的直接和间接影响，这些残疾是通过自我报告的残疾状态和认知表现来定义的，在不同的种族-民族群体（非洲裔美国人、西班牙裔、白色）中，并进行纵向评估。 此外，我们将使用临床诊断（在临床共识会议中建立）作为金标准，或者通过使用不假设金标准的潜在类模型，评估残疾的自我和代理报告的准确性。 本研究的一个重要特点是使用运动和过程技能（AMPS）评估，这是一种职业评估工具，用于评估日常生活活动中的功能限制。 AMPS评估产生运动和认知/过程限制的分数，这些限制干扰IADL/BADL任务的有效和安全性能。 OT将在受试者家中进行AMPS评估，沿着对身体损伤的详细评估（以及对家庭和社区环境的测量）。 母WHICAP研究将提供认知表现和神经医学状态的数据。 我们的主要目标是测试残疾的因果（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/过程限制间接相关。 我们将测试这种间接影响是否对某些老年人群体更强（例如，轻度残疾）。 这一发现表明，残疾可能会减少通过补救运动和认知/处理技能，以及通过努力减少损害。

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.