School of Public Health and Community Medicine, Institution of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Front Public Health. 2023 Mar 13;11:1011439. doi: 10.3389/fpubh.2023.1011439. eCollection 2023.
Socioeconomic position (SEP) strongly predicts late-life cognitive health, yet the pathways between SEP and cognitive function remain unclear. This study assessed whether and to what extent the association between SEP and cognitive function in the adult population in rural South Africa is mediated by some health conditions, behavioral factors, and social capital factors.
In this cross-sectional study, we used data from the 2014-15 "Health and Aging Africa: A Longitudinal Study of an INDEPTH Community in South Africa" (HAALSI) cohort, including 5,059 adults aged 40+ years from the Agincourt sub-district in Mpumalanga Province, South Africa. SEP, the independent variable, was measured based on ownership of household goods. Cognitive function, the dependent variable, was assessed using questions related to time orientation and immediate and delayed word recall. We used the multiple-mediation analysis on 4125 individuals with complete values on all variables to assess the mediating roles of health conditions (hypertension, diabetes, obesity, and disability), behavioral factors (leisure physical activity, alcohol consumption, and tobacco smoking), and social capital factors (community's willingness to help, trust, sense of safety, and social network contact) in the association between SEP and cognitive function.
Compared to adults in the poorest wealth quintile, those in the richest wealth quintile had better cognition (β = 0.903, < 0.001). The mediation analysis revealed that health conditions mediated 20.7% of the total effect of SEP on cognitive function. In comparison, 3.3% was mediated by behavioral factors and only 0.7% by social capital factors. In the multiple-mediator model, 17.9% of the effect of SEP on cognitive function was jointly mediated by health conditions, behavioral factors, and social capital factors.
Low socioeconomic position is a significant factor associated with poor cognitive function among adults aged 40 years and above in South Africa. Health conditions mainly mediate the effects between SEP and cognitive function. Therefore, actions to prevent and control chronic health conditions can serve as the entry point for intervention to prevent poor cognitive function among people with low socioeconomic status.
社会经济地位（SEP）强烈预测晚年认知健康，但 SEP 与认知功能之间的关系仍不清楚。本研究评估了南非农村地区成年人群体中，SEP 与认知功能之间的关联是否以及在何种程度上受到某些健康状况、行为因素和社会资本因素的影响。
在这项横断面研究中，我们使用了 2014-15 年“非洲健康与老龄化：南非一个 INDEPTH 社区的纵向研究”（HAALSI）队列的数据，该队列包括南非姆普马兰加省阿格因库尔次区的 5059 名 40 岁及以上成年人。SEP 是自变量，基于家庭用品的所有权进行测量。认知功能是因变量，通过与时间定向、即时和延迟单词回忆相关的问题进行评估。我们使用多元中介分析对 4125 名所有变量均有完整值的个体进行了分析，以评估健康状况（高血压、糖尿病、肥胖和残疾）、行为因素（休闲体育活动、饮酒和吸烟）以及社会资本因素（社区帮助意愿、信任、安全感和社会网络联系）在 SEP 与认知功能之间的关联中的中介作用。
与最贫穷财富五分位数的成年人相比，最富有财富五分位数的成年人认知能力更好（β=0.903，<0.001）。中介分析显示，健康状况解释了 SEP 对认知功能总效应的 20.7%。相比之下，行为因素解释了 3.3%，而社会资本因素仅解释了 0.7%。在多重中介模型中，SEP 对认知功能的影响有 17.9%是通过健康状况、行为因素和社会资本因素共同中介的。
低社会经济地位是南非 40 岁及以上成年人认知功能差的一个重要因素。健康状况主要中介了 SEP 与认知功能之间的关系。因此，预防和控制慢性健康状况的行动可以作为干预的切入点，防止社会经济地位较低的人认知功能下降。
