Harmonizing Cognitive Assessment in International Surveys on Aging

描述（由申请人提供）：为了响应NIA关于协调老龄化纵向跨国调查的项目公告（pas 07-387），拟议研究的目的是“协调”四项国际老龄化调查的认知功能测量-美国HRS，英国老龄化纵向研究（ELSA），欧洲健康，老龄化和退休调查（SHARE）和韩国老龄化纵向研究（KLSoA）。认知功能受损，通常是由于阿尔茨海默病和其他痴呆症，被认为是老年人功能下降和丧失独立性的一个主要原因。认知功能测量现在是正在进行的健康和退休调查（HRS）的一个组成部分，并已被纳入以HRS为模型的其他国际老龄化纵向研究中。然而，不同调查的测量方法差异很大，并且得到的验证有限。在国际老龄化调查中纳入认知评估，为认知障碍在独立中的作用以及对老年认知障碍患者援助需求的政策反应提供了跨国比较的机会，但前提是可以建立不同人群认知功能的测量等效性。项目反应理论（IRT）和分类与回归树（CART）是新的测量技术，为在调查和国家中实施认知功能和严重认知障碍的等效测量结构提供了有希望的方法。在IRT下，即使在不同的组中管理不同的项目，也可以计算出测量结构的可比分数。CART根据一个因变量对项目进行分类，并将用于制定针对具体国家的算法，以便对因认知缺陷而日常功能受损最严重的人进行跨国比较。我们在这个项目中的目标是1)首先构建和评估全球认知功能和严重认知障碍的标准化分数，然后2)使用IRT方法生成认知功能分数，证明各调查的测量等效，以及3)使用CART方法开发特定国家的认知功能项目组合，这些项目在各国的日常功能中表现出类似的预期损伤。通过使用这些技术来“协调”国际老龄化研究中使用的不同认知功能项目，本研究为有效的跨国比较认知障碍在健康轨迹中的作用以及为老年认知障碍个体提供帮助的家庭和社会所面临的相关挑战提供了方法基础。认知功能受损，最常由阿尔茨海默病和其他痴呆症引起，被认为是老年人功能下降和丧失独立性的主要原因。国际上对衰老的纵向研究包括认知功能的测量，但测量结果差异很大。本项目应用新的测量技术，构建认知功能和严重认知障碍的等效测量结构，为今后老年认知障碍患者护理和服务需求的跨国比较研究奠定基础。

DESCRIPTION (provided by applicant): The purpose of the proposed research, in response to NIA's Program Announcement regarding Harmonization of Longitudinal Cross-National Surveys of Aging (PAS-07-387) is to "harmonize" cognitive functioning measurement across four international surveys of aging - the HRS in the US, the English Longitudinal Study of Aging (ELSA), the European Survey of Health, Aging, and Retirement (SHARE), and the Korean Longitudinal Study of Aging (KLSoA). Impaired cognitive functioning, most often due to Alzheimer's disease and other dementias, is recognized as a major source of functional decline and loss of independence among older people. Cognitive functioning measures are now an integral part of the ongoing Health and Retirement Survey (HRS) and have been incorporated in other international longitudinal studies of aging modeled on the HRS. Measures vary substantially across surveys, however, and have received limited validation. Inclusion of cognitive assessments in international surveys of aging presents opportunities for cross-national comparisons of the role of cognitive impairment in independence, and of policy responses to needs for assistance of older cognitively impaired people, but only if the measurement equivalence of cognitive functioning across populations can be established. Item Response Theory (IRT) and Classification and Regression Tree (CART) are new measurement techniques that offer promising approaches to operationalizing equivalent measurement constructs for cognitive functioning and severe cognitive impairment across surveys and countries. Under IRT, comparable scores can be calculated for a measured construct even when different items are administered across groups. CART classifies items with regard to a dependent variable, and will be used to develop country specific algorithms that allow cross national comparisons of persons most impaired in everyday functioning due to cognitive deficits. Our aims in this project are 1) to first construct and evaluate standardized scores for global cognitive functioning and severe cognitive impairment, then 2) to use an IRT approach to generate cognitive functioning scores that demonstrate measurement equivalence across surveys, and 3) to use a CART approach to develop country- specific combinations of cognitive functioning items that exhibit similar expected impairment in everyday functioning across countries. By using these techniques to "harmonize" the disparate cognitive functioning items used across international studies of aging, this research provides the methodological underpinnings for valid cross-national comparisons of the role of cognitive impairment in health trajectories and the associated challenges to families and societies of providing assistance to older cognitively impaired individuals. PUBLIC HEALTH RELEVANCE: Project Narrative Impaired cognitive functioning, most often due to Alzheimer's disease and other dementias, is recognized as a major source of functional decline and loss of independence among older people. International longitudinal studies of aging are including measures of cognitive functioning, but measures vary substantially. This project applies new measurement techniques to develop equivalent measurement constructs for cognitive functioning and severe impairment across surveys, providing a foundation for future comparative cross-national research on care and service needs of older cognitively impaired individuals.