Population ageing is a global phenomenon. The United Nations estimates that the world population aged over 60 will have increased 3-fold from 1950 to 2050, to reach 21% of the population. 1 This compositional shift is happening fastest in low-and middle-income countries (LMIC). 2 South Africa in particular is undergoing a dramatic demographic and epidemiological transition, and little is known about the socioeconomic determinants or consequences of transition. This study, following important findings in previous studies in Agincourt 3-6 and South Africa in general, 7-9 is set up to inform us about morbidity, mortality and aetiological factors shaping these trends. Various ageing studies, including the Studies on Global Ageing and Adult Health (SAGE) and the 2015 Global Burden of Disease, found that noncommunicable diseases, driven mainly by population growth and ageing, have become leading causes of death and disability globally, including in LMIC such as South Africa. 10-14 At the same time, the share of the population 60 and above in South Africa is estimated to increase from 7.8% in 2012 to 14.8% in 2050, 15 and the population aged 50 and over living with HIV will triple by 2040. 16 We established the cohort 'Health and Ageing in Africa: A Longitudinal Study of an INDEPTH Community' in South Africa (HAALSI) in the INDEPTH Health and Demographic Surveillance System (HDSS) site of Agincourt, as a harmonized sister study to the Health and Retirement Study (HRS) in the USA 17 and other similar studies worldwide, including ELSA in the UK, 18

IntroductionThe rapid ageing of populations around the world is accompanied by increasing prevalence of multimorbidity. This study is one of the first to present the prevalence of multimorbidity that includes HIV in the complex epidemiological setting of South Africa, thus filling a gap in the multimorbidity literature that is dominated by studies in high-income or low-HIV prevalence settings.MethodsOut of the full sample of 5059 people aged 40+, we analysed cross-sectional data on 10 conditions from 3889 people enrolled in the Health and Ageing in Africa: A longitudinal study of an INDEPTH Community in South Africa (HAALSI) Programme. Two definitions of multimorbidity were applied: the presence of more than one condition and the presence of conditions from more than one of the following categories: cardiometabolic conditions, mental disorders, HIV and anaemia. We conducted descriptive and regression analyses to assess the relationship between prevalence of multimorbidity and sociodemographic factors. We examined the frequencies of the most prevalent combinations of conditions and assessed relationships between multimorbidity and physical and psychological functioning.Results69.4 per cent (95% CI 68.0 to 70.9) of the respondents had at least two conditions and 53.9% (52.4–55.5) of the sample had at least two categories of conditions. The most common condition groups and multimorbid profiles were combinations of cardiometabolic conditions, cardiometabolic conditions and depression, HIV and anaemia and combinations of mental disorders. The commonly observed positive relationships between multimorbidity and age and decreasing wealth were not observed in this population, namelydue to different epidemiological profiles in the subgroups, with higher prevalence of HIV and anaemia in the poorer and younger groups, and higher prevalence of cardiometabolic conditions in the richer and older groups. Both physical functioning and well-being negatively associated with multimorbidity.DiscussionMore coordinated, long-term integrated care management across multiple chronic conditions should be provided in rural South Africa.

Collin Payne and colleagues investigated development of disabilities and years expected to live with disabilities in participants 45 years and older participating in the Malawi Longitudinal Survey of Families and Health. Please see later in the article for the Editors' Summary

Rationale Little research has evaluated the life course drivers of cognitive aging in South Africa. Objectives We investigated the relationships of self-rated childhood health and father’s occupation during childhood with later-life cognitive function score and whether educational attainment mediated these relationships among older South Africans living in a former region of Apartheid-era racial segregation. Methods Data were from baseline assessments of “Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community” (HAALSI), a population-based study of 5059 men and women aged ≥40 years in 2015 in rural Agincourt sub-district, South Africa. Childhood health, father’s occupation during childhood, and years of education were self-reported in study interviews. Cognitive measures assessed time orientation, numeracy, and word recall, which were included in a z-standardized latent cognitive function score variable. Linear regression models adjusted for age, sex, and country of birth were used to estimate the total and direct effects of each childhood risk factor, and the indirect effects mediated by years of education. Results Poor childhood health predicted lower cognitive scores (total effect = −0.28; 95% CI = −0.35, −0.21, versus good); this effect was not mediated by educational attainment. Having a father in a professional job during childhood, while rare (3% of sample), predicted better cognitive scores (total effect = 0.25; 95% CI = 0.10, 0.40, versus unskilled manual labor, 29% of sample). Half of this effect was mediated by educational attainment. Education was linearly associated with later-life cognitive function score (0.09; 95% CI = 0.09, 0.10 per year achieved). Conclusion In this post-Apartheid, rural South African context, older adults with poor self-reported childhood health or whose father worked in unskilled manual labor had relatively poor cognitive outcomes. Educational attainment strongly predicted cognitive outcomes, and appeared to be, in part, a mechanism of social stratification in later-life cognitive health in this context.

BackgroundFrailty is a key predictor of death and dependency, yet little is known about frailty in sub-Saharan Africa despite rapid population ageing. We describe the prevalence and correlates of phenotypic frailty using data from the Health and Aging in Africa: Longitudinal Studies of an INDEPTH Community cohort.MethodsWe analysed data from rural South Africans aged 40 and over. We used low grip strength, slow gait speed, low body mass index, and combinations of self-reported exhaustion, decline in health, low physical activity and high self-reported sedentariness to derive nine variants of a phenotypic frailty score. Each frailty category was compared with self-reported health, subjective wellbeing, impairment in activities of daily living and the presence of multimorbidity. Cox regression analyses were used to compare subsequent all-cause mortality for non-frail (score 0), pre-frail (score 1–2) and frail participants (score 3+).ResultsFive thousand fifty nine individuals (mean age 61.7 years, 2714 female) were included in the analyses. The nine frailty score variants yielded a range of frailty prevalences (5.4% to 13.2%). For all variants, rates were higher in women than in men, and rose steeply with age. Frailty was associated with worse subjective wellbeing, and worse self-reported health. Both prefrailty and frailty were associated with a higher risk of death during a mean 17 month follow up for all score variants (hazard ratios 1.29 to 2.41 for pre-frail vs non-frail; hazard ratios 2.65 to 8.91 for frail vs non-frail).ConclusionsPhenotypic frailty could be measured in this older South African population, and was associated with worse health, wellbeing and earlier death.Electronic supplementary materialThe online version of this article (10.1186/s12877-017-0694-y) contains supplementary material, which is available to authorized users.