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.

Patterns and predictors of COVID-19 vaccination among young adults at 44 US sites: Secondary analysis of a randomized, controlled, open-label trial, March - December 2021.

BACKGROUND: The introduction of vaccines during the COVID-19 pandemic provided an opportunity to slow transmission of SARS-CoV-2, but initial uptake of COVID-19 vaccination was slow. We analyzed data from a randomized clinical trial of the mRNA-1273 vaccine (NCT04811664) to describe the patterns of uptake of COVID-19 vaccines among young adults. METHODS: The CoVPN 3006 trial randomized adults ages 18-29 from 44 sites in the United States to receive 1) immediate mRNA-1273 vaccination from the study site, or 2) standard of care, including the option to seek vaccination at any time in the future. Randomization occurred between March and November 2021, and an observational arm of adults who declined vaccination was enrolled beginning June 2021. Among participants in the standard of care (SoC) or Vaccine Declined arms, we estimated demographic, behavioral, and health history correlates of vaccination, and the four-month cumulative incidence of COVID-19 vaccination using inverse probability weighted Kaplan-Meier estimators. RESULTS: Among 728 SoC and 470 Vaccine Declined participants, 79% and 16% received COVID-19 vaccination, respectively. SoC and Vaccine Declined participants were more likely to seek and receive vaccination if they reported COVID-19 preventive behaviors, including wearing masks, physically distancing, and avoiding large gatherings. We identified strong predictors of vaccination in the Vaccine Declined arm, including attending class in person (adjusted risk ratio [aRR]: 0.47, 95% confidence interval [CI] 0.21, 1.03), having a COVID-19 relevant medical condition (aRR: 1.95, 95% CI: 0.89, 4.26), and avoiding large gatherings (aRR: 2.24, 95% CI: 1.18, 4.25), though low vaccination rates in this arm led to imprecise estimates. CONCLUSIONS: Individuals who initially decline vaccination can be convinced to vaccinate, particularly if they are already practicing other forms of COVID-19 prevention. Continued outreach and education from the scientific community can combat low vaccine confidence.

Impact of the South African Child Support Grant on memory decline and dementia probability in rural and low-income mothers, 2014-2021.

INTRODUCTION: Aging populations across sub-Saharan Africa are rapidly expanding, leading to an increase in the burden of Alzheimer's disease and related dementias (ADRD). Cash transfer interventions are one plausible mechanism to combat ADRD at a population-level in low-income settings. We exploited exogenous variation in eligibility for South Africa's Child Support Grant (CSG) to estimate the longitudinal association between potential CSG benefit and cognitive trajectories in rural mothers with <10 children (n = 1090). METHODS: South Africa's CSG delivers monthly cash payments to primary caregivers, predominantly mothers, to offset the costs associated with child rearing. This study implemented a quasi-experimental design using data (2014-2022) from a rural, low-income cohort in the Agincourt research area, South Africa. We fit linear mixed effects models and generalized linear models to estimate the association of potential CSG benefit per eligible child with memory decline and dementia probability, respectively. We stratified all models by the mother's total number of children (1-4 and 5-9) and examined effect modification by household wealth and the mother's education level. RESULTS: Having above median CSG per eligible child was associated with higher baseline memory scores (ß = 0.12 SD units, 95% CI = 0.02, 0.22) but steeper memory decline (ß = -0.02 SD units, 95% CI = -0.04, -0.00) compared to below median CSG. Within stratified analyses, this effect was primarily observed among mothers with 5-9 children. No associations were observed between potential CSG per eligible child and dementia probability. CONCLUSIONS: Our findings support the use of large-scale cash transfers as a promising intervention to promote healthy cognitive aging in mid-life women within rural, low-income settings. However, we found evidence that the CSG in its current structure may not be sufficient support for women to sustain measurable cognitive benefits over the long-term.

Mid-Life Household Food Insecurity and Subsequent Memory Function and Rate of Decline in Rural South Africa, 2004-2022.

INTRODUCTION: We aimed to investigate mid-life food insecurity over time in relation to subsequent memory function and rate of decline in Agincourt, rural South Africa. METHODS: Data from the longitudinal Agincourt Health and Socio-Demographic Surveillance System (Agincourt HDSS) were linked to the population-representative Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI). Food insecurity (yes vs. no) and food insecurity intensity (never/rarely/sometimes vs. often/very often) in the past month were assessed every 3 years from 2004 to 2013 in Agincourt HDSS. Cumulative exposure to each food insecurity measure was operationalized as 0, 1, and ≥2 time points. Episodic memory was assessed from 2014/15 to 2021/22 in HAALSI. Mixed-effects linear regression models were fitted to investigate the associations of each food insecurity measure with memory function and rate of decline over time. RESULTS: A total of 3,186 participants (mean age [SD] in 2004: 53 [12.87]; range: 30-96) were included and 1,173 (36%) participants experienced food insecurity in 2004, while this figure decreased to 490 (15%) in 2007, 489 (15%) in 2010, and 150 (5%) in 2013. Experiencing food insecurity at one time point (vs. never) from 2004 to 2013 was associated with lower baseline memory function (ß = -0.095; 95% CI: -0.159 to -0.032) in 2014/15 but not rate of memory decline. Higher intensity of food insecurity at ≥2 time points (vs. never) was associated with lower baseline memory function (ß = -0.154, 95% CI: -0.338 to 0.028), although the estimate was imprecise. Other frequencies of food insecurity and food insecurity intensity were not associated with memory function or decline in the fully adjusted models. CONCLUSION: In this setting, mid-life food insecurity may be a risk factor for lower later-life memory function, but not decline.

Household food and water insecurity and its association with diarrhoea, respiratory illness, and stunting in Ecuadorian children under 5 years.

Household food and water insecurity has been previously associated with adverse health consequences in children. However, these relationships are understudied in middle-income Latin American populations such as in Ecuador, where a high prevalence of food and water insecurity has been reported. Using cross-sectional data from 2018 Ecuadorian National Health and Nutrition Survey, we examined the association of household food insecurity (HFI), household water insecurity (HWI), and concurrent HFI-HWI with diarrhoea, respiratory illness (RI), and stunting in 20,510 children aged ≤59 months. HFI was measured using the Food Insecurity Experience Scale. HWI was defined when households responded negatively to one or more of four drinking water indicators. Maternal caregivers reported on child diarrhoea and RI episodes during the previous 2 weeks. Measured length or height was used to assess stunting. We constructed log-binomial regression models to estimate the associations of HFI, HWI, and concurrent HFI-HWI with child outcomes. Moderate-severe HFI was associated with a higher prevalence of diarrhoea (PR = 1.39; 95% CI: 1.18, 1.63) and RI (PR = 1.34; 95% CI: 1.22, 1.47), HWI with a higher prevalence of RI (PR = 1.13; 95% CI: 1.04, 1.22), and concurrent HFI-HWI with a higher prevalence of diarrhoea (PR = 1.30; 95% CI: 1.05, 1.62) and RI (PR = 1.45; 95% CI: 1.29, 1.62). Stunting was not associated with HFI, HWI nor concurrent HFI-HWI. These findings suggest that HFI and HWI can independently and jointly act to negatively affect children's health. Policies and interventions aimed at alleviating both food and water insecurity are needed to bring sustained health improvements in Ecuadorian children.

The Impact of Old Age Pension Eligibility on Alcohol Consumption: Evidence From a Population-Based Study in Rural South Africa.

Background and Objectives: Alcohol causes more than 3 million deaths a year globally and contributes to over 5% of global disease and injury. Heavy drinking and alcohol use disorders among older adults have increased in the last 10-15 years. For individuals living in low-income countries, where wages are low and unemployment is high, old age pensions may provide a significant increase in household income. In turn, the receipt of supplementary income may increase spending on alcohol. Earlier life factors and socioeconomic status may affect alcohol consumption, making it difficult to directly assess the impact of income on alcohol consumption. This study reduces the potential for endogeneity with other life factors by exploiting an exogenous increase in income from old age pensions to isolate the impact of extra income on alcohol consumption for older adults. Research Design and Methods: We used a regression discontinuity design to assess changes in drinking patterns among rural, low-income adults who were 3 years below and 3 years above South Africa's Old Age Pension Grant eligibility threshold (age 60). We assessed this relationship separately by gender and for employed and unemployed individuals. Results: We observed a significantly increased alcohol use associated with the Old Age Pension Grant eligibility for employed men (ß = 4.57, 95% confidence interval: 1.72-12.14). We did not observe this same trend for unemployed men or for women. Discussion and Implications: The analysis in this study indicates that increased income from reaching the pension eligibility age may contribute to an increase in alcohol consumption for employed men. Interventions, such as informational campaigns on the risks of alcohol consumption for older adults or age-appropriate health interventions to help individuals reduce alcohol consumption, targeted around the time of pension eligibility age for employed men may help to reduce alcohol-related harms in low-income, rural sub-Saharan African settings.

The Impact of the Older Person's Grant Expansion on Hypertension Among Older Men in Rural South Africa: Findings From the HAALSI Cohort.

Background and Objectives: Hypertension is a major modifiable contributor to disease burden in sub-Saharan Africa. We exploited an expansion to age eligibility for men in South Africa's noncontributory public pension to assess the impact of pension eligibility on hypertension in a rural, low-income South African setting. Research Design and Methods: Data were from 1 247 men aged ≥60 in the population-representative Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa in 2014/2015. We identified cohorts of men from 0 (controls, aged ≥65 at pension expansion) through 5 years of additional pension eligibility based on their birth year. Using the modified Framingham Heart Study hypertension risk prediction model, and the Wand et al. model modified for the South African population, we estimated the difference in the probabilities of hypertension for men who benefitted from the pension expansion relative to the control. We conducted a negative control analysis among older women, who were not eligible for pension expansion, to assess the robustness of our findings. Results: Older men with 5 additional years of pension eligibility had a 6.9-8.1 percentage point greater probability of hypertension than expected without the pension expansion eligibility. After accounting for birth cohort effects through a negative control analysis involving older women reduced estimates to a 3.0-5.2 percentage point greater probability of hypertension than expected. We observed a mean 0.2 percentage point increase in the probability of hypertension per additional year of pension eligibility, but this trend was not statistically significant. Discussion and Implications: Although the Older Person's Grant is important for improving the financial circumstances of older adults and their families in South Africa, expanded pension eligibility may have a small, negative short-term effect on hypertension among older men in this rural, South African setting.

Child support grant expansion and cognitive function among women in rural South Africa: Findings from a natural experiment in the HAALSI cohort.

BACKGROUND: Cash transfers are a promising but understudied intervention that may protect cognitive function in adults. Although South Africa has a rapidly ageing population, little is known about the nature of association between cash transfers and cognitive function in this setting. OBJECTIVES: We leveraged age-eligibility expansions to South Africa's Child Support Grant (CSG) to investigate the association between duration of CSG eligibility and cognitive function of biological mothers of child beneficiaries in South Africa. METHODS: We analysed 2014/2015 baseline data from 944 women, aged 40-59 years with at least one CSG-eligible child, enrolled in the population-representative HAALSI cohort in Agincourt, South Africa. Duration of CSG eligibility for each mother was calculated based on the birth dates of all their children and the CSG age-eligibility expansion years (2003-2012). Cognitive function was measured using a cognitive battery administered at the HAALSI baseline interview. Linear regression was used to estimate the association between duration of CSG eligibility, dichotomized as low (≤10 years) and high (>10 years) eligibility, and cognitive function z-scores of the mothers. RESULTS: High vs. low duration of CSG eligibility, was associated with higher cognitive function z-scores in the full sample [ß: 0.15 SD units; 95% CI: 0.04, 0.26; p-value = 0.01]. In mothers with one to four lifetime children, but not five or more, high vs. low duration of CSG eligibility, was associated with higher cognitive function z-scores [ß: 0.19 SD units; 95% CI: 0.05, 0.34, p-value = 0.02]. CONCLUSION: Government cash transfers given to support raising children may confer substantial protective effects on the subsequent cognitive function of mothers. Further studies are needed to understand how parity may influence this relationship. Our findings bring evidence to policymakers for designing income supplementation programmes to promote healthy cognitive ageing in low-income settings.

Mid-life employment trajectories and subsequent memory function and rate of decline in rural South Africa, 2000-22.

AIM: To investigate mid-life employment trajectories in relation to later-life memory function and rate of decline in rural South Africa. METHODS: Data from the Agincourt Health and Socio-Demographic Surveillance System were linked to the 'Health and Ageing in Africa: A Longitudinal Study of an INDEPTH Community in South Africa' (HAALSI) in rural Agincourt, South Africa (N = 3133). Employment was assessed every 4 years over 2000-12 as being employed (0, 1, 2 and ≥3 time points), being employed in a higher-skill occupation (0, 1, 2 and ≥3 time points) and dynamic employment trajectories identified using sequence analysis. Latent memory z-scores were assessed over 2014-22. Mixed-effects linear regression models were fitted to examine the associations of interest. RESULTS: Sustained mid-life employment from 2000-12 (ß = 0.052, 95% CI: -0.028 to 0.132, 1 vs 0 time points; ß = 0.163, 95% CI: 0.077 to 0.250, 2 vs 0 time points; ß = 0.212, 95% CI: 0.128 to 0.296, ≥3 vs 0 time points) and greater time spent in a higher-skill occupation (ß = 0.077, 95% CI: -0.020 to 0.175, 1 vs 0 time points; ß = 0.241, 95% CI: 0.070 to 0.412, 2 vs 0 time points; ß = 0.361, 95% CI: 0.201 to 0.520, ≥3 vs 0 time points) were associated with higher memory scores in 2014/15, but not subsequent rate of memory decline. Moving from a lower-skill to higher-skill occupation was associated with higher memory function, but a faster rate of decline over 2014-22. CONCLUSIONS: Sustained mid-life employment, particularly in higher-skill occupations, may contribute to later-life memory function in this post-Apartheid South African setting.

Prevalence of and Risk Factors for Peripheral Artery Disease in Rural South Africa: A Cross-Sectional Analysis of the HAALSI Cohort.

BACKGROUND: The burden of peripheral artery disease (PAD) is increasing in low- and middle-income countries. Existing literature from sub-Saharan Africa is limited and lacks population-representative estimates. We estimated the burden and risk factor profile of PAD for a rural South African population. METHODS AND RESULTS: We used data from 1883 participants from a rural, low-income cohort of South African adults aged 40 to 69 years with available ankle-brachial index measurements. We defined clinical PAD as ankle-brachial index ≤0.90 or >1.40, and borderline PAD as ankle-brachial index >0.90 and ≤1.00. We compared the distribution of sociodemographic variables, biomarkers, and comorbidities across PAD classifications. To identify associated factors, we calculated unadjusted and age-sex-adjusted prevalence ratios (PRs) with log-binomial models. Overall, 6.6% (95% CI, 5.6-7.7) of the sample met the diagnostic criteria for clinical PAD, while 44.7% (95% CI, 42.4-47.0) met the diagnostic criteria for borderline PAD. Age (PR: 1.9 [95% CI, 1.2-3.1] for ages 50-59 years compared with 40-49 years; PR: 2.5 [95% CI, 1.5-4.0] for ages 60-69 years compared with 40-49 years); diagnosed hypertension (PR: 1.53 [95% CI, 1.08-2.17]); and C-reactive protein (PR: 1.08 [95% CI, 1.03-1.12]) were associated with increased prevalence of clinical PAD. All other examined factors were not significantly associated with clinical PAD. CONCLUSIONS: We found high PAD prevalence for younger age groups compared with previous research and a lack of statistical evidence for the influence of traditional risk factors for this rural, low-income population. Future research should focus on identifying the underlying risk factors for PAD in this setting. South African policymakers and clinicians should consider expanded screening for early PAD detection in rural areas.

Disease awareness and healthcare utilization in rural South Africa: a comparative analysis of HIV and diabetes in the HAALSI cohort.

BACKGROUND: Studies from rural South Africa indicate that people living with HIV (PLHIV) may have better health outcomes than those without, potentially due to the frequent healthcare visits necessitated by infection. Here, we examined the association between HIV status and healthcare utilization, using diabetes as an illustrative comparator of another high-burden, healthcare-intensive disease. METHODS: Our exposure of interest was awareness of positive disease status for both HIV and diabetes. We identified 742 individuals who were HIV-positive and aware of their status and 305 who had diabetes and were aware of their status. HIV-positive status was further grouped by viral suppression. For each disease, we estimated the association with (1) other comorbid, chronic conditions, (2) health facility visits, (3) household-level healthcare expenditure, and (4) per-visit healthcare expenditure. We used log-binomial regression models to estimate prevalence ratios for co-morbid chronic conditions. Linear regression models were used for all other outcomes. RESULTS: Virally suppressed PLHIV had decreased prevalence of chronic conditions, increased public clinic visits [ß = 0.59, 95% CI: 0.5, 0.7], and reduced per-visit private clinic spending [ß = -60, 95% CI: -83, -6] compared to those without HIV. No differences were observed in hospitalizations and per-visit spending at hospitals and public clinics between virally suppressed PLHIV and non-PLHIV. Conversely, diabetic individuals had increased prevalence of chronic conditions, increased visits across facility types, increased household-level expenditures (ß = 88 R, 95% CI: 29, 154), per-visit hospital spending (ß = 54 R, 95% CI: 7, 155), and per-visit public clinic spending (ß = 31 R, 95% CI: 2, 74) compared to those without diabetes. CONCLUSIONS: Our results suggest that older adult PLHIV may visit public clinics more often than their HIV-negative counterparts but spend similarly on a per-visit basis. This provides preliminary evidence that the positive health outcomes observed among PLHIV in rural South Africa may be explained by different healthcare engagement patterns. Through our illustrative comparison between PLHIV and diabetics, we show that shifting disease burdens towards chronic and historically underfunded diseases, like diabetes, may be changing the landscape of health expenditure inequities.

Efficacy of Messenger RNA-1273 Against Severe Acute Respiratory Syndrome Coronavirus 2 Acquisition in Young Adults From March to December 2021.

Background: The efficacy of messenger RNA (mRNA)-1273 against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is not well defined, particularly among young adults. Methods: Adults aged 18-29 years with no known history of SARS-CoV-2 infection or prior vaccination for coronavirus disease 2019 (COVID-19) were recruited from 44 US sites from 24 March to 13 September 2021 and randomized 1:1 to immediate vaccination (receipt of 2 doses of mRNA-1273 vaccine at months 0 and 1) or the standard of care (receipt of COVID-19 vaccine). Randomized participants were followed up for SARS-CoV-2 infection measured by nasal swab testing and symptomatic COVID-19 measured by nasal swab testing plus symptom assessment and assessed for the primary efficacy outcome. A vaccine-declined observational group was also recruited from 16 June to 8 November 2021 and followed up for SARS-CoV-2 infection as specified for the randomized participants. Results: The study enrolled 1149 in the randomized arms and 311 in the vaccine-declined group and collected >122 000 nasal swab samples. Based on randomized participants, the efficacy of 2 doses of mRNA-1273 vaccine against SARS-CoV-2 infection was 52.6% (95% confidence interval, -14.1% to 80.3%), with the majority of infections due to the Delta variant. Vaccine efficacy against symptomatic COVID-19 was 71.0% (95% confidence interval, -9.5% to 92.3%). Precision was limited owing to curtailed study enrollment and off-study vaccination censoring. The incidence of SARS-CoV-2 infection in the vaccine-declined group was 1.8 times higher than in the standard-of-care group. Conclusions: mRNA-1273 vaccination reduced the incidence of SARS-CoV-2 infection from March to September 2021, but vaccination was only one factor influencing risk. Clinical Trials Registration: NCT04811664.

Structural brain morphology in young adult women who have been choked/strangled during sex: A whole-brain surface morphometry study.

INTRODUCTION: Being choked/strangled during partnered sex is an emerging sexual behavior, particularly prevalent among young adult women. Using a multiparameter morphometric imaging approach, we aimed to characterize neuroanatomical differences between young adult women (18-30 years old) who were exposed to frequent sexual choking and their choking naïve controls. METHODS: This cross-sectional study consisted of two groups (choking [≥4 times in the past 30 days] vs. choking-naïve group). Participants who reported being choked four or more times during sex in the past 30 days were enrolled in the choking group, whereas those without were assigned to the choking naïve group. High-resolution anatomical magnetic resonance imaging (MRI) data were analyzed using both volumetric features (cortical thickness) and geometric features (fractal dimensionality, gyrification, sulcal depth). RESULTS: Forty-one participants (choking n = 20; choking-naïve n = 21) contributed to the final analysis. The choking group showed significantly increased cortical thickness across multiple regions (e.g., fusiform, lateral occipital, lingual gyri) compared to the choking-naïve group. Widespread reductions of the gyrification were observed in the choking group as opposed to the choking-naïve group. However, there was no group difference in sulcal depth. The fractal dimensionality showed bi-directional results, where the choking group exhibited increased dimensionality in areas including the postcentral gyrus, insula, and fusiform, whereas decreased dimensionality was observed in the bilateral superior frontal gyrus and pericalcarine cortex. CONCLUSION: These data in cortical morphology suggest that sexual choking events may be associated with neuroanatomical alteration. A longitudinal study with multimodal assessment is needed to better understand the temporal ordering of sexual choking and neurological outcomes.

Wearable alcohol monitors for alcohol use data collection among college students: Feasibility and acceptability.

OBJECTIVE: We assessed the feasibility and acceptability of using BACtrack Skyn wearable alcohol monitors for alcohol research in a college student population. METHODS: We enrolled n = 5 (Sample 1) and n = 84 (Sample 2) Indiana University undergraduate students to wear BACtrack Skyn devices continuously over a 5-day to 7-day study period. We assessed feasibility in both samples by calculating compliance with study procedures, and by analyzing amount and distributions of device output [e.g., transdermal alcohol content (TAC), temperature, motion]. In Sample 1, we assessed feasibility and acceptability with the Feasibility of Intervention Measure (FIM) scale and the Acceptability of Intervention Measure (AIM) scale. RESULTS: All participants were able to successfully use the alcohol monitors, producing a total of 11,504 h of TAC data. TAC data were produced on 567 days of the 602 total possible days of data collection. The distribution of the TAC data showed between-person variation, as would be expected with between-person differences in drinking patterns. Temperature and motion data were also produced as expected. Sample 1 participants (n = 5) reported high feasibility and acceptability of the wearable alcohol monitors in survey responses with a mean FIM score of 4.3 (of 5.0 possible score) and mean AIM score of 4.3 (of 5.0 possible score). CONCLUSIONS: The high feasibility and acceptability we observed underscore the promise of using BACtrack Skyn wearable alcohol monitors to improve our understanding of alcohol consumption among college students, a population at particularly high risk for alcohol-related harms.

Development and validation of a model for measuring alcohol consumption from transdermal alcohol content data among college students.

BACKGROUND AND AIMS: Transdermal alcohol content (TAC) data collected by wearable alcohol monitors could potentially contribute to alcohol research, but raw data from the devices are challenging to interpret. We aimed to develop and validate a model using TAC data to detect alcohol drinking. DESIGN: We used a model development and validation study design. SETTING: Indiana, USA PARTICIPANTS: In March to April 2021, we enrolled 84 college students who reported drinking at least once a week (median age = 20 years, 73% white, 70% female). We observed participants' alcohol drinking behavior for 1 week. MEASUREMENTS: Participants wore BACtrack Skyn monitors (TAC data), provided self-reported drinking start times in real time (smartphone app) and completed daily surveys about their prior day of drinking. We developed a model using signal filtering, peak detection algorithm, regression and hyperparameter optimization. The input was TAC and outputs were alcohol drinking frequency, start time and magnitude. We validated the model using daily surveys (internal validation) and data collected from college students in 2019 (external validation). FINDINGS: Participants (N = 84) self-reported 213 drinking events. Monitors collected 10 915 hours of TAC. In internal validation, the model had a sensitivity of 70.9% (95% CI = 64.1%-77.0%) and a specificity of 73.9% (68.9%-78.5%) in detecting drinking events. The median absolute time difference between self-reported and model-detected drinking start times was 59 min. Mean absolute error (MAE) for the reported and detected number of drinks was 2.8 drinks. In an exploratory external validation among five participants, number of drinking events, sensitivity, specificity, median time difference and MAE were 15%, 67%, 100%, 45 minutes and 0.9 drinks, respectively. Our model's output was correlated with breath alcohol concentration data (Spearman's correlation [95% CI] = 0.88 [0.77, 0.94]). CONCLUSION: This study, the largest of its kind to date, developed and validated a model for detecting alcohol drinking using transdermal alcohol content data collected with a new generation of alcohol monitors. The model and its source code are available as Supporting Information (https://osf.io/xngbk).

The impact of a randomized cash transfer intervention on mortality of adult household members in rural South Africa, 2011-2022.

BACKGROUND: Increasing socioeconomic resources through cash transfer payments could help promote healthy longevity. However, research in this area is limited due to endogeneity in cash transfer exposures and limited geographic representation. METHODS: We leveraged the HPTN 068 randomized cash transfer trial, conducted from 2011 to 2015 in a rural setting in South Africa. We assessed long-term mortality follow-up (until March 2022) on older adult members (n = 3568) of households enrolled in the trial from the complete Agincourt Health and socio-Demographic Surveillance System census of the underlying source population. The trial intervention was a monthly cash payment of 300 Rand conditional on school enrollment of index young women. The payments were split between the young woman (1/3) and their caregiver (2/3). Young women and their households were randomized 1:1 to intervention vs. control. We used Cox PH models to compare mortality rates in older adults living in intervention vs. control households. FINDINGS: The cash transfer intervention did not significantly impact mortality in the full sample [HR (95% CI): 0.94 (0.80, 1.10)]. However, we observed strong protective effects of the cash transfer intervention among those with above-median household assets [HR (95% CI): 0.66 (0.50, 0.86)] and higher educational attainment [HR (95% CI): 0.37 (0.15, 0.93)]. INTERPRETATION: Our findings indicate that short-term cash transfers can lead to reduced mortality in certain subgroups of older adults with higher baseline socioeconomic status. Future work should focus on understanding the optimal timing, structure, and targets to maximize the benefits of cash transfer programs in promoting healthy aging and longevity.

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.

The Effects of Participation in an Intensive HIV Prevention Trial on Long-Term Socio-Demographic Outcomes Among Young Women in Rural South Africa.

BACKGROUND: Research trial participation may influence health outcomes regardless of the intervention assigned, but is often not assessed. SETTING: We investigated how participation in an HIV prevention trial (the HIV Prevention Trials Network (HPTN) 068 study) affected health outcomes 4 years after the study in adolescent girls and young women in South Africa beyond effects of the tested intervention. METHODS: We developed an analytical cohort that included the HIV Prevention 068 trial (HPTN 068) trial participants from the Agincourt Health and Demographic Surveillance System and resembled HPTN 068 trial enrollees (aged 13-20 years and in grades 8-11 in 2011) using inverse probability of treatment weights. We estimated risk differences for the association between trial participation and education and early parity (age <20 years) in 2019, after accounting for differences at baseline between the trial participants and nonparticipants. RESULTS: There were 3442 young women enrolled in grades 8-11 in 2011; 1669 were in the HPTN 068 trial. Trial participants were more likely to have completed secondary school by 2019 (adjusted RD (aRD) 5.0%, 95% confidence interval (CI) 2.2%, 7.9%; 82.3% in trial participants vs. 77.2% in nonparticipants). Trial participants had similar risk of parity before age 20 compared with nontrial participants (aRD 2.3%, 95% CI: -0.8%, 5.5%). CONCLUSIONS: Trial participation did not seem to influence early parity, but did increase educational attainment. Our results are compatible with an explanation of Hawthorne effects from trial participation on schooling behaviors that were small, but observable even 4 years after the end of the trial.

Child Support Grant expansion and cognitive function among women in rural South Africa: findings from a natural experiment in HAALSI cohort.

Cash transfers are a promising but understudied intervention that may protect cognitive function in adults by promoting their cognitive reserve. South Africa has a rapidly ageing population, however, less is known about the nature of association between cash transfers and cognitive function in this setting. We leveraged natural experiments from Child Support Grant (CSG) age-eligibility expansions to investigate the association between duration of CSG eligibility and cognitive function among biological mothers of child beneficiaries in South Africa. We analysed 2014/2015 baseline data from 944 women, aged 40 - 59 years with at least one CSG-eligible child, enrolled in the HAALSI cohort in Agincourt, South Africa. Duration of CSG eligibility for each mother was calculated based on the birth dates of all their children and the CSG age eligibility expansion years. Cognitive function was measured using a cognitive battery administered to the mothers at baseline interview. Linear regression was used to estimate the association between duration of CSG eligibility, dichotomized as low (≤10 years) and high (>10 years) eligibility, and cognitive function z-scores of the mothers. Our study finds that high duration of CSG eligibility, compared to low, was associated with higher cognitive function z-scores in the full sample [ß: 0.15 SD; 95% CI: 0.04, 0.26; p-value = 0.01]. In mothers with one to four lifetime children, but not five or more, high duration of CSG eligibility, compared to low, was associated with higher cognitive function z-scores [ß: 0.19 SD; 95% CI: 0.05, 0.34, p-value = 0.02]. Government cash transfers given to support raising children may confer substantial protective effect on cognitive function of mothers in their mid-life. Further studies are needed to understand how parity may influence this relationship. Our findings bring evidence to policymakers for designing income supplementation programmes to promote healthy cognitive ageing in low-income settings.

In-person classroom instruction and risk of SARS-CoV-2 infection among undergraduates at Indiana University, Fall 2020.

Objective: To examine how in-person classroom instruction was related to risk of SARS-CoV-2 infection in undergraduate students. Participants: Indiana University undergraduate students (n = 69,606) enrolled in Fall 2020, when courses with in-person and remote instruction options were available. Methods: Students participated weekly in mandatory SARS-CoV-2 RT-PCR asymptomatic testing by random selection, supplemented with symptomatic testing as needed. We used log-binomial regression models to estimate the association between number of in-person credit hours and the risk of SARS-CoV-2 infection over the course of the semester. Results: Overall 5,786 SARS-CoV-2 cases were observed. Increased in-person credit hour exposures were not associated with increased risk of SARS-CoV-2 overall [aRR (95% CI): 0.98 (0.97,0.99)], nor within specific subgroups (Greek affiliation and class). Conclusions: In-person instruction did not appear to increase SARS-CoV-2 transmission in a university setting with rigorous protective measures in place, prior to mass vaccine rollout and prior to delta variant emergence.