Health and Aging in Africa: A Longitudinal Study in South Africa (HAALSI)

Like many low- and middle-income countries, South Africa has experienced complex demographic and epidemiologic transitions in the last few decades, with uneven declines in mortality related to infectious (primarily HIV-related) and non-communicable diseases. Many adults in South Africa are now surviving to older ages and developing multiple chronic diseases. Of these diseases, some of the least understood are related to dementia and Alzheimer’s Disease. By 2050, more than 75% of global dementia cases are projected to occur in low- and middle-income countries, yet to date, little is understood about the nature of aging in the region, and the biological, social, and economic factors that shape patterns of dementia risk and resilience.

The Harvard Center for Population and Development Studies, in partnership with the MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt) of the University of the Witwatersrand was awarded a P01 grant in 2013 from the National Institute on Aging to study the drivers and consequences of HIV and non-communicable diseases in an aging population in Agincourt, South Africa. From 2014–2015, a first wave of interview and biomarker data were collected from a sample of men and women aged 40 and older in Agincourt. The grant was renewed in 2017 for a five-year period, and two additional waves of data collection took place in 2018 and 2021.

In 2023, The Health and Aging in Africa: A Longitudinal Study in South Africa (HAALSI) study was renewed for another 5-year period, and involves a major expansion of the project with a focus on dementia and cognitive decline, as well as major diseases and disorders (cardiometabolic disease and HIV) that impact cognitive function. The team is planning a 4th and 5th survey wave of our community-representative cohort in rural Agincourt, South Africa, in addition to the launch of a nationally representative longitudinal HAALSI survey across South Africa, with partners at the Southern Africa Labour and Development Research Unit at the University of Cape Town.

HAALSI is led by an interdisciplinary team of collaborators from:

The HAALSI team’s research focuses on exploring the interrelationships between:
Alzheimer’s Disease and related dementias • physical & cognitive functioning • lifestyle risk factors • household income & expenditure • depression & mental health • social networks & family composition • HIV infection • cardiometabolic disease

The HAALSI study design is finely tuned to capture characteristics specific to the aging process in South Africa, as well as to harmonize with the Health and Retirement Study (HRS) and sister studies in India, China, Brazil, the UK, Europe, and the U.S. Both the community and national surveys include an in-depth cognitive assessment on a sub-sample of participants using the Harmonized Cognitive Assessment Protocol (HCAP). In this way, the HAALSI data provide a unique opportunity to compare the biological, social, and economic determinants of chronic diseases and dementia, and their effects on functional and health outcomes in aging populations.