Charles F. and Joanne Knight Alzheimer Disease Research Center, Department of Neurology, Washington University, School of Medicine, St. Louis, MO, USA.
Department of Psychological & Brain Sciences, Washington University in St. Louis, St. Louis, MO, USA.
J Int Neuropsychol Soc. 2023 Jun;29(5):459-471. doi: 10.1017/S135561772200042X. Epub 2022 Sep 5.
Smartphones have the potential for capturing subtle changes in cognition that characterize preclinical Alzheimer's disease (AD) in older adults. The Ambulatory Research in Cognition (ARC) smartphone application is based on principles from ecological momentary assessment (EMA) and administers brief tests of associative memory, processing speed, and working memory up to 4 times per day over 7 consecutive days. ARC was designed to be administered unsupervised using participants' personal devices in their everyday environments.
We evaluated the reliability and validity of ARC in a sample of 268 cognitively normal older adults (ages 65-97 years) and 22 individuals with very mild dementia (ages 61-88 years). Participants completed at least one 7-day cycle of ARC testing and conventional cognitive assessments; most also completed cerebrospinal fluid, amyloid and tau positron emission tomography, and structural magnetic resonance imaging studies.
First, ARC tasks were reliable as between-person reliability across the 7-day cycle and test-retest reliabilities at 6-month and 1-year follow-ups all exceeded 0.85. Second, ARC demonstrated construct validity as evidenced by correlations with conventional cognitive measures ( = 0.53 between composite scores). Third, ARC measures correlated with AD biomarker burden at baseline to a similar degree as conventional cognitive measures. Finally, the intensive 7-day cycle indicated that ARC was feasible (86.50% approached chose to enroll), well tolerated (80.42% adherence, 4.83% dropout), and was rated favorably by older adult participants.
Overall, the results suggest that ARC is reliable and valid and represents a feasible tool for assessing cognitive changes associated with the earliest stages of AD.
智能手机有可能捕捉到认知的细微变化，这些变化特征是老年人群中临床前阿尔茨海默病（AD）的表现。基于生态瞬时评估（EMA）原理开发的认知动态监测（ARC）智能手机应用程序，每天对参与者进行 4 次短暂的联想记忆、处理速度和工作记忆测试，连续 7 天。ARC 的设计目的是在参与者的日常环境中使用他们自己的个人设备进行无人监督的管理。
我们评估了认知正常的 268 名老年人（年龄 65-97 岁）和 22 名轻度痴呆症患者（年龄 61-88 岁）样本中 ARC 的可靠性和有效性。参与者至少完成了一个 7 天的 ARC 测试周期和常规认知评估；大多数人还完成了脑脊液、淀粉样蛋白和 tau 正电子发射断层扫描和结构磁共振成像研究。
首先，ARC 任务具有可靠性，7 天周期内的个体间可靠性以及 6 个月和 1 年随访时的测试-重测可靠性均超过 0.85。其次，ARC 表现出构念效度，因为它与常规认知测量相关（综合评分之间的相关性为 0.53）。第三，ARC 测量与基线时的 AD 生物标志物负担具有相似程度的相关性，与常规认知测量相似。最后，密集的 7 天周期表明 ARC 是可行的（86.50%的参与者选择入组），具有良好的耐受性（80.42%的依从性，4.83%的失访率），并且受到老年参与者的好评。
总的来说，结果表明 ARC 具有可靠性和有效性，并且是评估与 AD 最早阶段相关的认知变化的可行工具。
