Cohort Profile Update: Cognition and dementia in the Health and Aging in Africa Longitudinal Study of an INDEPTH community in South Africa (HAALSI dementia)

The Health and Aging in Africa Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) is a harmonized sister study to the US Health and Retirement Study (HRS).Established in 2015, it includes 5059 individuals aged 40 and over, in a rural community in Agincourt, South Africa.• In light of the projected rise of dementia burden in sub-Saharan Africa, the HAALSI Dementia study was launched in 2019 to investigate the prevalence, incidence and risk factors of cognitive decline and dementia in South Africa.• The HAALSI Dementia sample includes 635 individuals, 50 years and older, of whom 99 also participated in an ancillary magnetic resonance imaging (MRI) sub-study.• The HAALSI Dementia study encompasses a comprehensive, culturally sensitive cognitive battery with multidomain psychometric scales, informant interviews and neurological evaluations, and has sufficient overlap with international Harmonized Cognitive Assessment Protocol (HCAP) and HRS studies to enable cross-calibration.