Supplementary Material for: Incidence of Cognitive Impairment during Aging in Rural South Africa: Evidence from HAALSI, 2014 to 2019

Introduction: Despite rapid population aging, there are currently limited data on the incidence of aging-related cognitive impairment in sub-Saharan Africa. We aimed to determine the incidence of cognitive impairment and its distribution across key demographic, social, and health-related factors among older adults in rural South Africa. Methods: Data were from in-person interviews with 3,856 adults aged ≥40 who were free from cognitive impairment at baseline in the population-representative cohort, “Health and Aging in Africa: a Longitudinal Study of an INDEPTH Community in South Africa” (HAALSI), in Agincourt sub-district, Mpumalanga province, South Africa (2014–19). Cognitive impairment was defined as scoring Results: The incidence of cognitive impairment was 25.7/1,000 person-years (PY; 95% confidence interval [CI]: 23.0–28.8), weighted for mortality (12%) and attrition (6%) over the 3.5-year mean follow-up (range: 1.5–4.8 years). Incidence increased with age, from 8.9/1,000 PY (95% CI: 5.2–16.8) among those aged 40–44 to 93.5/1,000 PY (95% CI: 75.9–116.3) among those aged 80+, and age-specific risks were similar by sex/gender. Incidence was strongly associated with formal education and literacy, as well as marital status, household assets, employment, and alcohol consumption but not with history of smoking, hypertension, stroke, angina, heart attack, diabetes, or prevalent HIV. Conclusions: This study presents some of the first incidence rate estimates for aging-related cognitive impairment in rural South Africa. Social disparities in incident cognitive impairment rates were apparent in patterns similar to those observed in many high-income countries.引言：尽管人口老龄化进程迅猛推进，目前撒哈拉以南非洲地区与衰老相关的认知障碍（cognitive impairment）发病数据仍极为匮乏。本研究旨在明确南非农村地区老年人群认知障碍的发病率，及其在关键人口学、社会学及健康相关因素中的分布特征。 方法：研究数据来源于南非姆普马兰加省阿金库尔分区2014至2019年开展的人群代表性队列研究——《非洲健康与老龄化：南非INDEPTH社区纵向研究》（Health and Aging in Africa: a Longitudinal Study of an INDEPTH Community in South Africa，以下简称HAALSI），共纳入3856名基线时无认知障碍的40岁及以上成年人，通过面对面访谈收集数据。认知障碍被定义为评分。 结果：在平均3.5年的随访期（范围1.5~4.8年）内，经12%的死亡率和6%的失访率加权校正后，认知障碍的发病率为25.7/1000人年（person-years, PY；95%置信区间[confidence interval, CI]：23.0~28.8）。发病率随年龄增长而升高：40~44岁人群的发病率为8.9/1000人年（95%CI：5.2~16.8），80岁及以上人群则升至93.5/1000人年（95%CI：75.9~116.3），且不同性别间的年龄别发病风险无显著差异。发病率与正规受教育程度、识字能力、婚姻状况、家庭资产、就业状态及饮酒行为显著相关，但与吸烟史、高血压、脑卒中、心绞痛、心肌梗死、糖尿病或现症HIV感染无明显关联。 结论：本研究提供了南非农村地区与衰老相关认知障碍的首批发病率估算数据之一。新发认知障碍发生率的社会差异模式与许多高收入国家中观察到的情况相似。