Effect of a cash transfer intervention on memory decline and dementia probability in older adults in rural South Africa.

Evidence on cash transfers as a population-level intervention to support healthy cognitive aging in low-income settings is sparse. We assessed the effect of a cash transfer intervention on cognitive aging outcomes in older South African adults. We leveraged the overlap in the sampling frames of a Phase 3 randomized cash transfer trial [HIV Prevention Trial Network (HPTN) 068, 2011-2015] and an aging cohort [Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community (HAALSI), 2014-2022] in rural Mpumalanga Province, South Africa. In 2011/12, young women and their primary caregivers were randomly assigned 1:1 to receive a monthly cash transfer or control. In 2014/2015, 862 adults aged 40+ y living in trial households were enrolled in the HAALSI cohort, with cognitive data collected in three waves over 7 y. We estimated the impact of the intervention on rate of memory decline and dementia probability scores. Memory decline in the cash transfer arm was 0.03 SD units (95% CI: 0.002, 0.05) slower per year than in the control arm. Dementia probability scores were three percentage points lower in the cash transfer arm than the control arm (ß = -0.03; 95% CI: -0.05, -0.001). Effects were consistent across subgroups. A modestly sized household cash transfer delivered over a short period in mid- to later-life led to a meaningful slowing of memory decline and reduction in dementia probability 7 y later. Cash transfer programs could help stem the tide of new dementia cases in economically vulnerable populations in the coming decades.

Producing Change to Understand the Social Determinants of Health: The Promise of Experiments for Social Epidemiology.

In this commentary, invited for the 100th anniversary of the Journal, we discuss the addition of randomized experiments, along with natural experiments that emulate randomized trials using observational data, as designs in the social epidemiologist's toolbox. These approaches transform the way we define and ask questions about social exposures. They compel us to ask questions about how well-defined interventions change a social exposure that might lead to changes in health. As such, experiments are of unique public health and policy significance. We argue that they are a powerful approach to advance our understanding of how well-defined changes in social exposures impact health, and how credible social policy reforms may be instrumental to address health inequalities. We focus on two research designs. The first is a "pure" randomized controlled trial (RCT) in which the investigator defines and randomly assigns the intervention. The second is a natural experiment, which exploits the fact that policies or interventions in the real world often involve an element of random assignment, emulating an RCT. To give the reader our bottom line: While acknowledging their limits, we continue to be very excited about the promise of RCTs and natural experiments to advance social epidemiology.

Employee Cardiometabolic Risk Following a Cluster-Randomized Workplace Intervention From the Work, Family and Health Network, 2009-2013.

Objectives. To examine whether workplace interventions to increase workplace flexibility and supervisor support and decrease work-family conflict can reduce cardiometabolic risk. Methods. We randomly assigned employees from information technology (n = 555) and long-term care (n = 973) industries in the United States to the Work, Family and Health Network intervention or usual practice (we collected the data 2009-2013). We calculated a validated cardiometabolic risk score (CRS) based on resting blood pressure, HbA1c (glycated hemoglobin), HDL (high-density lipoprotein) and total cholesterol, height and weight (body mass index), and tobacco consumption. We compared changes in baseline CRS to 12-month follow-up. Results. There was no significant main effect on CRS associated with the intervention in either industry. However, significant interaction effects revealed that the intervention improved CRS at the 12-month follow-up among intervention participants in both industries with a higher baseline CRS. Age also moderated intervention effects: older employees had significantly larger reductions in CRS at 12 months than did younger employees. Conclusions. The intervention benefited employee health by reducing CRS equivalent to 5 to 10 years of age-related changes for those with a higher baseline CRS and for older employees. Trial Registration. ClinicalTrials.gov Identifier: NCT02050204. (Am J Public Health. 2023;113(12):1322-1331. https://doi.org/10.2105/AJPH.2023.307413).

Effects of Pension Eligibility Expansion on Men's Cognitive Function: Findings from Rural South Africa.

Two-thirds of people living with Alzheimer's disease and related dementias (ADRD) live in low- and middle-income countries, and this figure is expected to rise as these populations are rapidly aging. Since evidence demonstrates links between socioeconomic status and slower rates of cognitive decline, protecting older adults' cognitive function in resource-limited countries that lack the infrastructure to cope with ADRD is crucial to reduce the burden it places on these populations and their health systems. While cash transfers are a promising intervention to promote healthy cognitive aging, factors such as household wealth and level of education often confound the ability to make causal inferences on the impact of cash transfers and cognitive function. This study uses a quasi-experimental design, leveraging an exogenous expansion to the Old Age Pension for men in South Africa, to approximate causal associations with cognitive function. We found evidence that there is a potential benefit of cash transfers at an earlier age for older individuals. As such, transfers such as pensions or other forms of direct basic income transfers may hold promise as potential interventions to promote healthy cognitive aging.

Eight-Year Depressive Symptom Trajectories and Incident Stroke: A 10-Year Follow-Up of the HRS (Health and Retirement Study).

BACKGROUND: Evidence suggests a link between depressive symptoms and risk of subsequent stroke. However, most studies assess depressive symptoms at only one timepoint, with few examining this relationship using repeatedly measured depressive symptoms. This study aimed to examine the relationship between depressive symptom trajectories and risk of incident stroke. METHODS: This prospective cohort included 12 520 US individuals aged ≥50 years enrolled in the Health and Retirement Study, free of stroke at study baseline (1998). We used the 8-item Center for Epidemiologic Studies Depression scale to assess depressive symptoms (high defined as ≥3 symptoms; low <3 symptoms) at 4 consecutive, biennial timepoints from 1998 to 2004. We assigned individuals to 5 predefined trajectories based on their scores at each timepoint (consistently low, decreasing, fluctuating, increasing, and consistently high). Using self-reported doctors' diagnoses, we assessed incident stroke over a subsequent 10-year period from 2006 to 2016. Cox regression models estimated the association of depressive symptom trajectories with risk of incident stroke, adjusting for demographics, health behaviors, and health conditions. RESULTS: During follow-up, 1434 incident strokes occurred. Compared with individuals with consistently low symptoms, individuals with consistently high depressive symptoms (adjusted hazard ratio, 1.18 [95% CI, 1.02-1.36]), increasing symptoms (adjusted hazard ratio, 1.31 [95% CI, 1.10-1.57]), and fluctuating symptoms (adjusted hazard ratio, 1.21 [95% CI, 1.01-1.46]) all had higher hazards of stroke onset. Individuals in the decreasing symptom trajectory group did not show increased stroke risk. CONCLUSIONS: Depressive symptom trajectories characterized by high symptoms at multiple timepoints were associated with increased stroke risk. However, a trajectory with depressive symptoms that started high but decreased over time was not associated with higher stroke risk. Given the remitting-relapsing nature of depressive symptoms, it is important to understand the relationship between depressive symptoms and stroke risk over time through repeated assessments.

Health Selection Into Eviction: Adverse Birth Outcomes and Children's Risk of Eviction Through Age 5 Years.

Adverse birth outcomes put children at increased risk of poor future health. They also put families under sudden socioeconomic and psychological strain, which has poorly understood consequences. We tested whether infants experiencing an adverse birth outcome-low birthweight or prematurity, as well as lengthy hospital stays-were more likely to be evicted in early childhood, through age 5 years. We analyzed 5,655 observations contributed by 2,115 participants in the Fragile Families and Child Wellbeing Study-a national, randomly sampled cohort of infants born in large US cities between 1998 and 2000-living in rental housing at baseline. We fitted proportional hazards models using piecewise logistic regression, controlling for an array of confounders and applying inverse probability of selection weights. Having been born low birthweight or preterm was associated with a 1.74-fold increase in children's hazard of eviction (95% confidence interval: 1.02, 2.95), and lengthy neonatal hospital stays were independently associated with a relative hazard of 2.50 (95% confidence interval: 1.15, 5.44) compared with uncomplicated births. Given recent findings that unstable housing during pregnancy is associated with adverse birth outcomes, our results suggest eviction and health may be cyclical and co-constitutive. Children experiencing adverse birth outcomes are vulnerable to eviction and require additional supports.

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 <1.5 standard deviations below the mean of the baseline distribution of orientation and episodic memory scores. Incidence rates and rate ratios for cognitive impairment were estimated according to key demographic, social, and health-related factors, adjusted for age, sex/gender, and country of birth. 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.

Work Redesign for the 21st Century: Promising Strategies for Enhancing Worker Well-Being.

Work is a key social determinant of population health and well-being. Yet, efforts to improve worker well-being in the United States are often focused on changing individual health behaviors via employer wellness programs. The COVID-19 health crisis has brought into sharp relief some of the limitations of current approaches, revealing structural conditions that heighten the vulnerability of workers and their families to physical and psychosocial stressors. To address these gaps, we build on existing frameworks and work redesign research to propose a model of work redesign updated for the 21st century that identifies strategies to reshape work conditions that are a root cause of stress-related health problems. These strategies include increasing worker schedule control and voice, moderating job demands, and providing training and employer support aimed at enhancing social relations at work. We conclude that work redesign offers new and viable directions for improving worker well-being and that guidance from federal and state governments could encourage the adoption and effective implementation of such initiatives. (Am J Public Health. 2021;111(10):1787-1795. https://doi.org/10.2105/AJPH.2021.306283).

Alcohol Consumption and Sexual Risk Behavior in an Aging Population in Rural South Africa.

We sought to characterize the relationship between alcohol consumption and sexual risk-taking in an aging population in rural South Africa. A cross-sectional analysis was conducted using baseline data from the Health and Ageing in Africa: a Longitudinal Study of an INDEPTH Community (HAALSI) cohort. We elicited information on sexual risk behavior and self-reported frequency of alcohol consumption among 5059 adults ≥ 40 years old. Multivariable models showed that more frequent alcohol consumption is associated with a higher number of sexual partners (ß: 1.38, p < .001) and greater odds of having sex for money (OR: 42.58, p < .001) in older adults in South Africa. Additionally, daily drinkers were more likely to have sex without a condom (OR: 2.67, p = .01). Older adults who drank more alcohol were more likely to engage in sexual risk-taking. Behavioral interventions to reduce alcohol intake should be considered to reduce STI and HIV transmission.

Older Adults Vastly Overestimate Both HIV Acquisition Risk and HIV Prevalence in Rural South Africa.

Perceptions of HIV acquisition risk and prevalence shape sexual behavior in sub-Saharan Africa (SSA). We used data from the Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa baseline survey. Data were collected through home-based interviews of 5059 people ≥ 40 years old. We elicited information on perceived risk of HIV acquisition and HIV prevalence among adults ≥ 15 and ≥ 50 years old. We first describe these perceptions in key subgroups and then compared them to actual estimates for this cohort. We then evaluated the relationship between sociodemographic characteristics and accurate perceptions of prevalence in regression models. Finally, we explored differences in behavioral characteristics among those who overestimated risk compared to those who underestimated or accurately estimated risk. Compared to the actual HIV acquisition risk of < 1%, respondents vastly overestimated this risk: 35% (95% CI: 32-37) and 34% (95% CI: 32-36) for men and women, respectively. Respondents overestimated HIV prevalence at 53% (95% CI: 52-53) for those ≥ 15 years old and 48% (95% CI: 48-49) for those ≥ 50 years old. True values were less than half of these estimates. There were few significant associations between demographic characteristics and accuracy. Finally, high overestimators of HIV prevalence tested themselves less for HIV compared to mild overestimators and accurate reporters. More than 30 years into the HIV epidemic, older people in a community with hyperendemic HIV in SSA vastly overestimate both HIV acquisition risk and prevalence. These misperceptions may lead to fatalism and reduced motivation for prevention efforts, possibly explaining the continued high HIV incidence in this community.