Amir Abbas Tahami Monfared, MD, PhD, ORCID: https://orcid.org/0000-0003-4003-3192, Eisai, Inc., 200 Metro Blvd, Nutley, NJ 07110, USA, Tel.: (201) 746-2112, Fax: (732) 791-1088, E-mail:
J Prev Alzheimers Dis. 2024;11(5):1183-1188. doi: 10.14283/jpad.2024.114.
Updated prevalence estimates along the continuum of Alzheimer's disease (AD) can foster a more nuanced and effective approach to managing AD within the current healthcare landscape.
This study aims to estimate the prevalence and severity distribution of dementia/AD (including mild, moderate, and severe stages) and all-cause mild cognitive impairment (MCI) in the United States using data from the Health and Retirement Study (HRS).
Retrospective study.
Data from the bi-annual HRS surveys involving in-depth interviews of a representative sample of Americans aged >50 years.
Dementia/AD and all-cause MCI patients from the 4 most recent HRS surveys (2014, 2016, 2018 and 2020).
AD was identified based on diagnosis (self-report). Cognitive performance (modified Telephone Interview of Cognitive Status [TICS-m]) scores in the dementia/AD range were also captured; all-cause MCI was similarly identified using the TICS-m. Dementia/AD and MCI prevalence, as well as the distribution by dementia/AD stage (mild, moderate, or severe), were estimated. Sampling weights developed by HRS were applied to ensure the sample's representativeness of the target population and unbiased estimates for population parameters.
Across the four HRS surveys, the total number of HRS respondents ranged from 15,000 to 21,000 (unweighted); 7,000 to 14,000 had TICS-m scores. The estimated prevalence of AD (all severity categories combined) in the 2014, 2016, 2018, and 2020 HRS surveys was 1.2%, 1.2%, 1.3% and 1.0%, respectively using the diagnosis-based approach; using the cognitive performance-based approach, 23-27% patients had scores in the dementia/AD ranges across the 4 surveys. The estimated prevalence of all-cause MCI was consistently 23% in each survey. In the 2020 survey, the distribution of mild, moderate, and severe disease stages was 34%, 45%, and 21%, respectively, in patients self-reporting an AD diagnosis, and 55%, 40%, and 5%, respectively in all patients meeting TICS-m threshold for dementia/AD.
The prevalence of AD diagnosis based on self-report was approximately 1% across the 4 most recent HRS surveys and may reflect the proportion of patients who have actively sought healthcare for AD. Among HRS survey respondents with cognitive scores available, over 20% were in the dementia/AD range. The distribution of disease by stage differed for self-reported AD diagnosis vs dementia/AD based on cognitive scores. Discordance in estimates of dementia/AD and stage distributions underscores a need for better understanding of clinical practice patterns in AD diagnosis, use of clinical assessment tools, and severity classification in the United States. Accurate patient identification is needed, especially early in the AD disease continuum, to allow for timely and appropriate initiation of new anti-amyloid treatments.
更新阿尔茨海默病（AD）连续体的患病率估计可以促进在当前医疗保健环境中更细致和有效的 AD 管理方法。
本研究旨在使用来自健康与退休研究（HRS）的数据，估计美国痴呆症/AD（包括轻度、中度和重度阶段）和所有原因轻度认知障碍（MCI）的患病率和严重程度分布。
回顾性研究。
来自 HRS 双年度调查的数据，涉及对>50 岁的美国代表性样本进行深入访谈。
来自 HRS 的最近 4 次调查（2014 年、2016 年、2018 年和 2020 年）的痴呆症/AD 和所有原因 MCI 患者。
AD 根据诊断（自我报告）确定。还记录了认知表现（改良电话访谈认知状态量表 [TICS-m]）在痴呆症/AD 范围内的评分；同样使用 TICS-m 来确定所有原因 MCI。估计了痴呆症/AD 和 MCI 的患病率，以及根据痴呆症/AD 阶段（轻度、中度或重度）的分布情况。HRS 制定的抽样权重用于确保样本代表性和人口参数的无偏估计。
在 HRS 的四次调查中，HRS 受访者的总数范围为 15000 至 21000（未加权）；有 7000 至 14000 人有 TICS-m 评分。使用基于诊断的方法，2014 年、2016 年、2018 年和 2020 年 HRS 调查中 AD（所有严重程度类别合并）的估计患病率分别为 1.2%、1.2%、1.3%和 1.0%；使用基于认知表现的方法，4 次调查中有 23-27%的患者 TICS-m 评分在痴呆症/AD 范围内。每个调查中所有原因 MCI 的估计患病率均保持在 23%。在 2020 年的调查中，自我报告 AD 诊断的患者中轻度、中度和重度疾病阶段的分布分别为 34%、45%和 21%，而在所有符合 TICS-m 痴呆症/AD 阈值的患者中，分别为 55%、40%和 5%。
基于自我报告的 AD 诊断的患病率在最近的 4 次 HRS 调查中约为 1%，可能反映了主动寻求 AD 治疗的患者比例。在有认知评分的 HRS 调查受访者中，超过 20%的人处于痴呆症/AD 范围内。自我报告的 AD 诊断与基于认知评分的痴呆症/AD 的疾病阶段分布不同。痴呆症/AD 和阶段分布的估计差异突出表明需要更好地了解美国 AD 诊断的临床实践模式、临床评估工具的使用和严重程度分类。需要准确识别患者，尤其是在 AD 疾病连续体的早期，以便及时和适当开始新的抗淀粉样蛋白治疗。
