Gross Alden L, Duhon Madeline, Ochieng Eric, Ikanga Jean N, Dow William H, Lee Jinkook, Walker Michael W, Layvant Michelle, Ngugi Anthony, Ehrlich Joshua R, Miguel Edward A
Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA.
Department of Economics, Pepperdine University, Malibu, California, USA.
BMJ Open. 2025 Aug 5;15(8):e096619. doi: 10.1136/bmjopen-2024-096619.
Cohort studies of ageing and cognitive decline typically do not begin fielding comprehensive cognitive assessments until older adulthood. However, for identifying preventable dementia risk factors, there is strong value in beginning at earlier ages. The case is especially compelling in sub-Saharan Africa, where the number of older individuals is expected to triple in the next three decades, and where risk factors may operate more intensively at earlier ages. This study reports on the adaptation and validity of the Harmonised Cognitive Assessment Protocol (HCAP) approach in the Kenya Life Panel Survey (KLPS), collected among middle-aged respondents.
To evaluate the validity of the HCAP approach in Kenya, this study assesses model fit statistics from confirmatory factor analyses (CFA) and tests measurement invariance by respondent characteristics.
Both rural and urban areas in Kenya.
A sample of n=5878 individuals from the KLPS, who have been surveyed regularly since they were schoolchildren in the 1990s. The HCAP assessment was administered in 2023 at an average age of 37 years (10-90 range 34 to 41).
For each individual, the CFA generates a general cognitive performance score, and cognitive performance scores for five distinct domains, including memory, executive functioning, language, orientation to time and place, and visuospatial functioning.
Fit of the models to the data was adequate for general cognitive performance (root mean squared error of approximation (RMSEA)=0.03; comparative fit index (CFI)=0.94; standardised root mean residual (SRMR)=0.05), language (RMSEA=0.02; CFI=0.95; SRMR=0.05) and good for memory (RMSEA=0.05; CFI=0.99; SRMR=0.02) and executive functioning (RMSEA=0.03; CFI=0.98; SRMR=0.03). The CFA indicate that the factor structure is consistent with findings from other countries and that reliability for the general cognitive performance score was high. Statistical models also suggest invariance at the scalar level for leading demographic (gender, age) and socioeconomic (education, occupational complexity) characteristics.
This study demonstrates that the cognitive functioning of mid-age Kenyans appears to be well captured by the adapted protocol. While there is a moderate decline in cognitive performance among older individuals, this relationship appears to be mediated by education, indicating that this KLPS HCAP provides a valuable baseline for studying future cognitive decline.
关于衰老与认知衰退的队列研究通常要到成年后期才开始进行全面的认知评估。然而，为了识别可预防的痴呆风险因素，在更早的年龄开始研究具有重要价值。在撒哈拉以南非洲，这种情况尤其引人注目，预计在未来三十年里，老年人口数量将增至三倍，而且风险因素可能在更早的年龄就更为密集地发挥作用。本研究报告了在肯尼亚生活面板调查（KLPS）中对中年受访者采用的统一认知评估方案（HCAP）方法的适应性及有效性。
为评估HCAP方法在肯尼亚的有效性，本研究评估了验证性因素分析（CFA）的模型拟合统计量，并按受访者特征检验测量不变性。
肯尼亚的农村和城市地区。
从KLPS中抽取的n = 5878名个体样本，自20世纪90年代他们还是学生时起就定期接受调查。2023年进行了HCAP评估，平均年龄为37岁（年龄范围10 - 90岁，34至41岁）。
对于每个个体，CFA生成一个总体认知表现分数，以及五个不同领域的认知表现分数，包括记忆、执行功能、语言、时间和地点定向以及视觉空间功能。
模型与数据的拟合对于总体认知表现（近似均方根误差（RMSEA）= 0.03；比较拟合指数（CFI）= 0.94；标准化均方根残差（SRMR）= 0.05）、语言（RMSEA = 0.02；CFI = 0.95；SRMR = 0.05）是合适的，对于记忆（RMSEA = 0.05；CFI = 0.99；SRMR = 0.02）和执行功能（RMSEA = 0.03；CFI = 0.98；SRMR = 0.03）是良好的。CFA表明因素结构与其他国家的研究结果一致，并且总体认知表现分数的可靠性很高。统计模型还表明，在主要人口统计学（性别、年龄）和社会经济（教育、职业复杂性）特征的标量水平上具有不变性。
本研究表明，经改编的方案能够很好地反映肯尼亚中年人的认知功能。虽然老年人的认知表现有适度下降，但这种关系似乎由教育介导，这表明该KLPS HCAP为研究未来认知衰退提供了有价值的基线。
