National Social Life, Health, and Aging Project: Rounds 4.2 and 4.4

国家社会生活、健康和老龄化项目（NSHAP）旨在研究老年人的社会、认知、心理和身体健康轨迹之间的联系，其中许多人将获得阿尔茨海默病和阿尔茨海默病相关痴呆（AD/ADRD）。NSHAP开始于2005 - 2006年，每5年收集一组丰富而独特的数据，包括社交网络、认知功能、心理健康、身体健康和AD/ADRD的临床诊断、药物、生物样本、感觉功能和加速度计测量的日常活动和睡眠的详细信息。第4轮（R4）目前正在进行中，将于2023年完成，届时将提供约3500名60-100岁受访者的最新数据。

The National Social Life, Health, and Aging Project (NSHAP) is designed to study the links between social, cognitive, mental, and physical health trajectories among older adults, many of whom will acquire Alzheimer’s disease and Alzheimer’s disease-related dementias (AD/ADRD). Started in 2005–06, NSHAP collects a rich and unique set of data at 5-year intervals, including detailed information on social networks, cognitive function, mental health, clinical diagnoses of physical health and AD/ADRD, medications, biological samples, sensory function, and accelerometer-measured daily activity and sleep. Round 4 (R4) is currently underway and when completed in 2023, will provide updated data on ~3,500 respondents aged 60–100. While NSHAP’s 5-year cadence may be adequate at younger ages, this is less true at older ages, especially among those who are experiencing health declines including onset of AD/ADRD and are thus at higher risk of rapid changes and mortality. We propose to augment NSHAP’s study design so researchers can study this part of the lifecourse in more detail. Specifically, we shall transition a subset of NSHAP respondents identified using data through R4 as being at greater risk of mortality to being followed-up every two years. A smaller, age-matched control group at low risk of mortality will also be included and all Black and Hispanic respondents will be included regardless of age or health status. To maximize the completeness and analytic value of information from respondents in increasingly poor physical and cognitive health, including Alzheimer's disease and Alzheimer’s disease-related dementias, we shall administer interviews with targeted measures to capture recent changes in their social, cognitive, and physical health and well-being, and to obtain spousal, proxy, and informant interviews when needed to enhance respondent data. Further, we propose to add new measures that are culturally attuned to the unique experiences of Black and Hispanic populations. This NSHAP subset and a two-year periodicity will allow the study of the antecedents and consequences of changes in key dimensions of health as they occur more rapidly in people’s final years, including AD/ADRD, daily activity, sleep, frailty, polypharmacy, and social well-being, for (1) those at high risk of mortality as compared to those at lower risk, and for (2) those at high risk who die during the period compared to those at high risk who do not die. This strategy differs from that often taken by studies of end of life in which a group of deceased individuals is studied retrospectively, thereby yielding conclusions conditional on having died.12 In contrast, our approach will allow researchers to make conclusions about the future for those currently alive, including onset and course of AD/ADRD, as well as permit us to refine our mortality prediction models. We test the overarching hypothesis that social well-being will modulate mortality risk. Throughout, we test competing hypotheses in which changes in social well-being precede changes in other health indicators such as Alzheimer’s disease and Alzheimer’s disease-related dementias that predispose toward early mortality.