Cohort profile: the Adverse Childhood Experiences cohort of the Malawi Longitudinal Study of Families and Health.

PURPOSE: The Adverse Childhood Experiences (ACE) cohort of the Malawi Longitudinal Study of Families and Health (MLSFH-ACE) is a study of adolescents surveyed during 2017-2021. It provides an important opportunity to examine the longitudinal impact of ACEs on health and development across the early life course. The MLSFH-ACE cohort provides rich data on adolescents, their children and adult caregivers in a low-income, high-HIV-prevalence context in sub-Saharan Africa (SSA). PARTICIPANTS: The MLSFH-ACE cohort is a population-based study of adolescents living in three districts in rural Malawi. Wave 1 enrolment took place in 2017-2018 and included 2061 adolescents aged 10-16 years and 1438 caregivers. Wave 2 took place in 2021 and included data on 1878 adolescents and 208 offspring. Survey instruments captured ACEs during childhood and adolescence, HIV-related behavioural risk, mental and physical health, cognitive development and education, intimate partner violence (IPV), marriage and aspirations, early transitions to adulthood and protective factors. Biological indicators included HIV, herpes simplex virus and anthropometric measurements. FINDINGS TO DATE: Key findings include a high prevalence of ACEs among adolescents in Malawi, a low incidence of HIV and positive associations between ACE scores and composite HIV risk scores. There were also strong associations between ACEs and both IPV victimisation and perpetration. FUTURE PLANS: MLSFH-ACE data will be publicly released and will provide a wealth of information on ACEs and adolescent outcomes in low-income, HIV-endemic SSA contexts. Future expansions of the cohort are planned to capture data during early adulthood.

Social Protection and Foundational Cognitive Skills during Adolescence: Evidence from a Large Public Works Program.

Many low- and middle-income countries have introduced public works programs (PWPs) to fight poverty. This paper provides the first evidence that children from families who benefit from PWPs show increased foundational cognitive skills. The results, based on unique tablet-based data collected as part of a long-standing longitudinal survey, show positive associations between participation in the Productive Safety Net Programme (PSNP) in Ethiopia during childhood with long-term memory and implicit learning, and suggestive evidence for working memory. These associations appear to be strongest for children whose households were still PSNP participants in the year of data collection. Evidence suggests that the association with implicit learning may be operating partially through children's time reallocation away from unpaid labor responsibilities, while the association with long-term memory may in part be due to the program's success in remediating nutritional deficits caused by early-life rainfall shocks.

Drivers of child marriages for girls: A prospective study in a low-income African setting.

Child marriage has adverse consequences for young girls. Cross-sectional research has highlighted several potential drivers of early marriage. We analyse drivers of child marriage using longitudinal data from rural Malawi, where rates of child marriage are among the highest in the world despite being illegal. Estimates from survival models show that 26% of girls in our sample marry before age 18. Importantly, girls report high decision-making autonomy vis-à-vis the decision to marry. We use multivariate Cox proportional hazard models to explore the role of 1) poverty and economic factors, 2) opportunity or alternatives to marriage, 3) social norms and attitudes, 4) knowledge of the law and 5) girls' agency. Only three factors are consistently associated with child marriage. First, related to opportunities outside marriage, girls lagging in school at survey baseline have significantly higher rates of child marriage than their counterparts who were at or near grade level. Second, related to social norms, child marriage rates are significantly lower among respondents whose caregivers perceive that members of their community disapprove of child marriage. Third, knowledge of the law has a positive coefficient, a surprising result. These findings are aligned with the growing qualitative literature describing contexts where adolescent girls are more active agents in child marriages.

Impact of laws prohibiting domestic violence on wasting in early childhood.

Intimate partner violence (IPV) affects an estimated 641 million women and girls globally with far-reaching consequences for the health of women and children. Yet, laws that prohibit domestic violence (DV) are not universal. Countries actively debate the effectiveness of DV laws in improving conditions given the inconclusive evidence on deterrent effects within households particularly in low- and middle-income countries that have limited infrastructure, and fewer resources to implement and enforce policy changes. This is the first study to rigorously examine the impact of DV laws on women's health decision-making and the intergenerational impact on children's wasting, a key predictor of mortality. We used the Demographic and Health Surveys (DHS) data collected between 2000-2020 across 23 African countries. Exploiting the staggered adoption of laws, we used a difference-in-differences study design to estimate the impact of DV laws in the treated countries compared to countries without such laws. We find that DV laws increased women's decision-making autonomy in healthcare by 16.7% as well as other measures of women's autonomy that matter for health such as financial autonomy by 6.3% and social mobility by 11.0%. The improvements in women's autonomy translated into reductions in the probability of wasting among children aged 0-23 months by 5.4% points, a 30.9% reduction from the mean. DV laws also reduced wasting among older children aged 24-59 months by 3.6% points, a 38.7% reduction from the mean. The laws were effective in all 6 countries analyzed individually that criminalized DV. A civil prohibition in the seventh country was not found to be effective. The effect was positive and significant for all wealth and geographical categories. Our findings demonstrate the value of enacting criminal laws that prohibit domestic violence as one important tool to reducing the profound health impacts of IPV, a critical health and human rights issue.

Does early nutrition predict cognitive skills during later childhood? Evidence from two developing countries.

The existing evidence linking early undernutrition to educational outcomes in developing countries is largely focused on assessing its impacts on grade attainment and achievement test scores, with limited evidence on the foundational cognitive skills required to perform well at school. We use unique data collected in Ethiopia and Peru as part of the Young Lives Study to investigate the relationship between early undernutrition and four foundational cognitive skills measured later in childhood, the first two of which measure executive functioning: working memory, inhibitory control, long-term memory, and implicit learning. We exploit the rich longitudinal data available to control for potential confounders at the household and individual level and for time-invariant community characteristics. We also take advantage of the availability of data for paired-siblings to obtain household fixed-effects estimates. In the latter specification, we find robust evidence that stunting at ~ age 5 is negatively related with executive functions measured years later, predicting reductions in working memory and inhibitory control by 12.6% and 5.8% of a standard deviation. Although the main cohort of Young Lives was around 12 years old when executive functions were measured, complementary results and analysis of the data available for the younger siblings suggest that the impact of stunting on executive functions-specifically, on working memory-starts at an earlier age. Our results shed light on the mechanisms that explain the relationship between early nutrition and school achievement tests suggesting that good nutrition is an important determinant of children's learning capacities.

The intergenerational effect of tuition-free lower-secondary education on children's nutritional outcomes in Africa.

One in five child deaths under age 5 are a result of severe wasting. Malnutrition at early ages is linked to lifelong consequences, such as reduced cognitive skills, reduced earnings in adulthood and chronic health conditions. Countries worldwide have committed to addressing child undernutrition, and ending hunger is foundational to the Millennium Development Goals. In this paper, we study the intergenerational effect of providing free tuition in secondary school on future children's nutrition. We combined a novel longitudinal dataset that captures educational policies for 40 African countries from 1990 to 2019 with the Demographic and Health Survey (DHS). We identified three countries that introduced free secondary education several years after implementing free primary education. Exploiting this variation in timing we estimate the additional impact of providing free secondary education over free primary education. Using a difference-in-difference approach, we find that introducing free secondary education significantly reduced wasting. Cohorts exposed to free secondary had an 18% relative decrease in wasting. The impact on cohorts exposed only to free primary was smaller and not statistically significant. Expanding free secondary education has long-term, intergenerational benefits and is an effective path to reducing malnutrition. Results are robust to different specifications.

Barker's Hypothesis Among the Global Poor: Positive Long-Term Cardiovascular Effects of in Utero Famine Exposure.

An influential literature on the Developmental Origins of Health and Disease (DOHaD) has documented that poor conditions in utero lead to higher risk of cardiovascular disease at older ages. Evidence from low-income countries (LICs) has hitherto been missing, despite the fact that adverse in utero conditions are far more common in LICs. We find that Malawians exposed in utero to the 1949 Nyasaland famine have better cardiovascular health 70 years later. These findings highlight the potential context specificity of the DOHaD hypothesis, with in utero adversity having different health implications among aging LIC individuals who were exposed to persistent poverty.

Assessing household financial burdens for preprimary education and associated socioeconomic inequalities: a case study in China.

BACKGROUND: Providing young children with universal access to preprimary education (PPE) is considered a powerful tool for human capital development and eliminating the intergenerational transmission of poverty. To remove household financial barrier for achieving universal PPE, this study proposed a measure to identify households incurring 'heavy financial burdens from paying for PPE' (HBPPE) and conducted a case study in China. METHODS: Using nationally representative data in 2019, we estimated the percentage of households with HBPPE (spent 7% or more of their total annual expenditure) and associated socioeconomic inequalities. We also applied a three-level logit regression model to investigate the factors associated with the probabilities of households incurring HBPPE. RESULTS: Half of the sampled households spent 7% or more of their expenditures on PPE. Households in the lowest wealth quintile (54%) or households with children attending private PPE (55%) had higher percentages of HBPPE than households in other wealth quintiles (eg, 51% in the highest wealth quintile) or households with children attending public kindergartens (41%). Logit regression analysis shows that the poorest households and households with children attending private kindergarten were more likely to incur HBPPE than their counterparts. CONCLUSION: To ensuring universal access to PPE in China, future policy should consider increasing the enrolment of children from low-income families in public kindergartens and increasing governmental investments in low-income households by subsidising children attending PPE.

Minimum Wages around Birth and Child Health.

This paper studies the effects of minimum wages in Indonesia around the time of birth on child height-for-age Z scores (HAZ) up to five years of age. Using variations in annual fluctuations in real minimum wages in different Indonesian provinces, it finds that children exposed to increases in minimum wages in their birth years have higher HAZ in the first five years of their lives. The estimated impacts are based on difference-in-differences models with biological-mother fixed effects and year-of-birth fixed effects and are robust to inclusion of multiple time-varying factors. The impacts are prominent particularly among male children.

Heterogenous trajectories in physical, mental and cognitive health among older Americans: Roles of genetics and life course contextual factors.

We investigate the roles of genetic predispositions, childhood SES and adult educational attainment in shaping trajectories for three important components of the overall health of older adults -- BMI, depressive symptoms and cognition. We use the Health & Retirement Study (HRS) and group-based trajectory modeling (GBTM) to identify subgroups of people who share the same underlying trajectories ages 51-94 years. After identifying common underlying health trajectories, we use fractional multinomial logit models to estimate associations of (1) polygenic scores for BMI, depression, ever-smoked, education, cognition and subjective wellbeing, (2) childhood SES and (3) educational attainment with the probabilities of trajectory group memberships. While genetic predispositions do play a part in predicting trajectory group memberships, our results highlight the long arm of socioeconomic factors. Educational attainment is the most robust predictor-it predicts increased probabilities of belonging to trajectories with BMI in the normal range, low depressive symptoms and very-high initial cognition. Childhood circumstances are manifested in trajectories to a lesser extent, with childhood SES predicting higher likelihood of being on the low depressive symptoms and very-high initial cognition trajectories. We also find suggestive evidence that associations of educational attainment on the probabilities of being on trajectories with BMI in the normal range, low depressive symptoms and very-high initial cognition vary with genetic predispositions. Our results suggest that policies to increase educational attainment may improve population health by increasing the likelihood of belonging to "good" aging trajectories.

Global tracking of access and quality in early childhood care and education.

Investments in early childhood care and education (ECCE) have contributed to a growing demand for internationally comparable data. Yet data on access to quality ECCE are not routinely collected in many countries, leading to limited information on equitable access to ECCE, quality of provision, and the impact on learning and wellbeing outcomes. This paper outlines the current status of global measurement of access to quality ECCE and identifies issues with definitions, availability, and accuracy of ECCE data across countries and outlines paths forward. We argue that estimates of access to ECCE should be based on children's participation in quality ECCE across multiple program types, rather than enrollment or attendance alone, given the critical importance of dosage and participation for ensuring positive benefits from ECCE. Governments, international organizations, and researchers all have roles to play in setting standards to define and monitor ECCE, generating workable tools for measuring nationally, and globally investing in national monitoring systems and routine household surveys to obtain accurate estimates of access to quality ECCE.

The effects of cash transfers on adult and child mortality in low- and middle-income countries.

Poverty is an important social determinant of health that is associated with increased risk of death1-5. Cash transfer programmes provide non-contributory monetary transfers to individuals or households, with or without behavioural conditions such as children's school attendance6,7. Over recent decades, cash transfer programmes have emerged as central components of poverty reduction strategies of many governments in low- and middle-income countries6,7. The effects of these programmes on adult and child mortality rates remains an important gap in the literature, however, with existing evidence limited to a few specific conditional cash transfer programmes, primarily in Latin America8-14. Here we evaluated the effects of large-scale, government-led cash transfer programmes on all-cause adult and child mortality using individual-level longitudinal mortality datasets from many low- and middle-income countries. We found that cash transfer programmes were associated with significant reductions in mortality among children under five years of age and women. Secondary heterogeneity analyses suggested similar effects for conditional and unconditional programmes, and larger effects for programmes that covered a larger share of the population and provided larger transfer amounts, and in countries with lower health expenditures, lower baseline life expectancy, and higher perceived regulatory quality. Our findings support the use of anti-poverty programmes such as cash transfers, which many countries have introduced or expanded during the COVID-19 pandemic, to improve population health.

Early Stimulation and Enhanced Preschool: A Randomized Trial.

OBJECTIVES: To estimate the impacts of 2 interventions, early stimulation (ES) for children aged <3 years and enhanced preschool (EP) for children aged 3+ years, and their interactions. METHODS: In Odisha, India, 192 villages were randomly assigned to ES or to no ES. Within each village, about 8 mothers with children initially aged 7 to 16 months were enrolled, receiving ES or no ES accordingly (n = 1449). Subsequently, when children were aged ∼3 years, the villages were rerandomized to either EP at Anganwadi centers or no EP. This yielded 4 groups: (1) ES and EP, (2) only ES, (3) only EP, and (4) no intervention. Trained Anganwadi workers ran the EP. Primary outcomes, measured at baseline and follow-up after ∼1 year, were children's IQ (summarizing cognition, language, and executive functioning) and school readiness (SR). Secondary outcomes were home environments, caregivers' child-development knowledge. and preschool quality. RESULTS: Fifteen months after ES ended, onlyES had a sustained benefit on IQ (0.18 SD, P <.04) and on SR (0.13 SD, P <.08). Only EP improved IQ (0.17 SD, P <.04) and SR (0.24 SD, P <.01). Receiving both interventions improved IQ (0.24 SD, P <.01) and SR (0.21 SD, P <.01). No statistically significant interactions between the 2 interventions were observed. CONCLUSIONS: Both ES and EP increased IQ and SR. Only ES impacts were sustained for 15 months. Only EP resulted in considerable catch-up for children who did not receive only ES. The absence of significant complementarities should be investigated further because of its profound policy implications.

Family play, reading, and other stimulation and early childhood development in five low-and-middle-income countries.

This paper used longitudinal data from five studies conducted in Bangladesh, Bhutan, Cambodia, Ethiopia, and Rwanda to examine the links between family stimulation and early childhood development outcomes (N = 4904; Mage = 51.5; 49% girls). Results from random-effects and more conservative child-fixed effects models indicate that across these studies, family stimulation, measured by caregivers' engagement in nine activities (e.g., reading, playing, singing), predicted increments in children's early numeracy, literacy, social-emotional, motor, and executive function skills (standardized associations ranged from 0.05 to 0.11 SD). Study-specific models showed variability in the estimates, with null associations in two out of the five studies. These findings indicate the need for additional research on culturally specific ways in which caregivers may support early development and highlight the importance of promoting family stimulation to catalyze positive developmental trajectories in global contexts. RESEARCH HIGHLIGHTS: Research on the links between family stimulation and early childhood development in low-and-middle-income countries (LMICs) is limited. We used longitudinal data from studies conducted in five LMICs to examine the links between family stimulation and early childhood development outcomes. Results suggest that family stimulation predicted increments in children's numeracy, literacy, social-emotional, motor, and executive function skills. We found variability in the observed estimates, with null associations in two out of the five studies, suggesting the need for additional research in LMICs.

Teacher depressive symptoms and children's school readiness in Ghana.

This study investigated associations between kindergarten teachers' (N = 208) depressive symptoms and students' (Ghanaian nationals, N = 1490, Mage  = 5.8) school-readiness skills (early literacy, early numeracy, social-emotional skills, and executive function) across 208 schools in Ghana over one school year. Teachers' depressive symptoms in the fall negatively predicted students' overall school-readiness skills in the spring, controlling for school-readiness skills in the fall. These results were primarily driven by social-emotional skills (r = .1-.3). There was evidence of heterogeneity by students' fall skill levels; teacher depressive symptoms predicted more negative spring overall school readiness for children who had higher fall school-readiness skills. Findings underscore the importance of teachers' mental health in early childhood education globally, with implications for policy and practice.

Longitudinal Associations Between Childhood Adversity and Adolescent Intimate Partner Violence in Malawi.

Adverse childhood experiences (ACEs)-including child maltreatment, witnessing violence, and household dysfunction-have been robustly associated with poor health in later life. There is also increasing evidence that those who experience childhood adversity are more likely subsequently to be victims or perpetrators of intimate partner violence (IPV). Most evidence, however, is cross-sectional and concentrated in high-income settings, and cannot be generalized to more diverse contexts. In contrast, this study assessed longitudinal relations between ACEs and IPV in a low-income country. We interviewed 1,878 adolescents in rural Malawi between 2017 and 2018 (aged 10-16) and again in 2021 (aged 13-20). Adolescents completed the Adverse Childhood Experience-International Questionnaire. Past-year physical, sexual, and emotional IPV victimization and perpetration were measured using the WHO's Violence Against Women Instrument. We estimated multivariate regression models between cumulative adversity (0-13 adversities) at baseline and IPV at follow-up among respondents who reported any romantic or sexual partnerships. The cumulative ACEs score was associated with emotional IPV victimization for boys (OR = 1.12 per ACE) and sexual IPV victimization for girls (OR = 1.18). The ACEs score demonstrated a significant association with perpetration for girls only (OR = 1.33 for emotional IPV). By using longitudinal data, we more rigorously demonstrated the critical role of childhood adversity in shaping later IPV behavior. There are ongoing efforts toward primary prevention of childhood adversity. Given the burden that adolescents already carry (six ACEs on average in our sample), we also need secondary interventions that can help interrupt the pathway from adversity to IPV. This calls for increased collaboration between those working to address violence against children and violence against women.

Do Incentives Crowd Out Motivation? A Feasibility Study of a Community Vector-Control Campaign in Peru.

Incentives are a useful tool in encouraging healthy behavior as part of public health initiatives. However, there remains concern about motivation crowd out-a decline in levels of motivation to undertake a behavior to below baseline levels after incentives have been removed-and few public health studies have assessed for motivation crowd out. Here, we assess the feasibility of identifying motivation crowd out following a lottery to promote participation in a Chagas disease vector control campaign. We look for evidence of crowd out in subsequent participation in the same behavior, a related behavior, and an unrelated behavior. We identified potential motivation crowd out for the same behavior, but not for related behavior or unrelated behaviors after lottery incentives are removed. Despite some limitations, we conclude that motivation crowd out is feasible to assess in large-scale trials of incentives.

Resilience, Accelerated Aging and Persistently Poor Health: Diverse Trajectories of Health in Malawi.

Individuals age at vastly different rates resulting in significant within-population heterogeneity in health and aging outcomes. This diversity in health and aging trajectories has rarely been investigated among low-income aging populations that have experienced substantial hardships throughout their lifecourses. Utilizing 2006-2018 data from the Malawi Longitudinal Study of Families and Health (MLSFH) and estimating group-based trajectory models (GBTM), our analyses identified three distinct lifecourse health trajectories: (1) comparatively good initial mental and physical health that persisted throughout the lifecourse ("resilient aging"); (2) relatively good initial mental and physical health that started to deteriorate during mid-adulthood ("accelerated aging"); and (3) poor initial mental and physical health that further declined over the lifecourse ("aging with persistently poor health"). For both physical and mental health, men were more likely to enjoy resilient aging than women. Predictors other than gender of trajectory membership sometimes confirmed, and sometimes contradicted, hypotheses derived from high-income country studies. Our analyses highlight the long arm of early life conditions and gender in determining aging trajectories and show that a non-trivial sub-population is characterized by aging with persistently poor health. The study uncovers widening gaps in health outcomes between those who age with resilience and those who experience accelerated aging.

Could a Shigella vaccine impact long-term health outcomes?: Summary report of an expert meeting to inform a Shigella vaccine public health value proposition, March 24 and 29, 2021.

Shigellosis is a leading cause of diarrhea and dysentery in young children from low to middle-income countries and adults experiencing traveler's diarrhea worldwide. In addition to acute illness, infection by Shigella bacteria is associated with stunted growth among children, which has been linked to detrimental long-term health, developmental, and economic outcomes. On March 24 and 29, 2021, PATH convened an expert panel to discuss the potential impact of Shigella vaccines on these long-term outcomes. Based on current empirical evidence, this discussion focused on whether Shigella vaccines could potentially alleviate the long-term burden associated with Shigella infections. Also, the experts provided recommendations about how to best model the burden, health and vaccine impact, and economic consequences of Shigella infections. This international multidisciplinary panel included 13 scientists, physicians, and economists from multiple relevant specialties. According to the panel, while the relationship between Shigella infections and childhood growth deficits is complex, this relationship likely exists. Vaccine probe studies are the crucial next step to determine whether vaccination could ameliorate Shigella infection-related long-term impacts. Infants should be vaccinated during their first year of life to maximize their protection from severe acute health outcomes and ideally reduce stunting risk and subsequent negative long-term developmental and health impacts. With vaccine schedule crowding, targeted or combination vaccination approaches would likely increase vaccine uptake in high-burden areas. Shigella impact and economic assessment models should include a wider range of linear growth outcomes. Also, these models should produce a spectrum of results-ones addressing immediate benefits for usual health care decision-makers and others that include broader health impacts, providing a more comprehensive picture of vaccination benefits. While many of the underlying mechanisms of this relationship need better characterization, the remaining gaps can be best addressed by collecting data post-vaccine introduction or through large trials.