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 were 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. The resulting study was called Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI). 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 study investigators received renewed funding through 2028 from the National Institute on Aging, allowing the project to expand to the Health and Aging in Africa: Longitudinal Studies in South Africa (HAALSA) family of studies. HAALSA is conducted at several levels in South Africa:

• HAALSA HARPS: Nationally representative survey (Health, Aging and Retirement Panel Study)
• HAALSA SAPRIN: HAALSA survey administered at SAPRIN nodes
• HAALSA Indepth: Community cohort in Agincourt (HAALSI)

This larger next phase of HAALSA includes the continuation of the decade-long community cohort study in Agincourt (HAALSA Indepth) for the 4th and 5th waves of data collection, while also expanding to conduct the first wave of a longitudinal nationally representative survey (HAALSA HARPS). The national survey will be led in collaboration with partners at the Southern Africa Labour and Development Research Unit at the University of Cape Town. The team is engaging directly with policy-makers and public health researchers in South Africa including Statistics South Africa, the South African Medical Research Council, and the South African Population Research Infrastructure Network (SAPRIN), as the country takes on new challenges around ensuring the healthy aging of its population.

HAALSA is led by an interdisciplinary team of collaborators from:

• Harvard T.H. Chan School of Public Health
• University of Witwatersrand, Johannesburg
• University of Cape Town
• Columbia University Department of Neurology

HAALSA continues to explore aging in South Africa, with focal areas in cognitive health, cardiometabolic disease, HIV and HIV treatment, public policies, social determinants of health, and health inequalities. Research focuses on exploring the interrelationships between: Alzheimer’s Disease and related dementias; physical and cognitive functioning; lifestyle risk factors; household income & expenditure; depression and mental health; social networks and family composition; HIV infection; and cardiometabolic disease.

The HAALSA 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 HAALSA 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. 

Portrait on homepage slideshow is by Jan Truter on Flickr