Whitney Schott

Postinfancy growth, schooling, and cognitive achievement: Young Lives

Background: Early life growth failure and resulting cognitive deficits are often assumed to be very difficult to reverse after infancy. Objective: We used data from Young Lives, which is an observational cohort of 8062 children in Ethiopia, India, Peru, and Vietnam, to determine whether changes in growth after infancy are associated with schooling and cognitive achievement at age 8 y. Design: We represented the growth by height-for-age z score at 1 y [HAZ(1)] and height-for-age z score at 8 y that was not predicted by the HAZ(1). We also characterized growth as recovered (stunted at age 1 y and not at age 8 y), faltered (not stunted at age 1 y and stunted at age 8 y), persistently stunted (stunted at ages 1 and 8 y), or never stunted (not stunted at ages 1 and 8 y). Outcome measures were assessed at age 8 y. Results: The HAZ(1) was inversely associated with overage for grade and positively associated with mathematics achievement, reading comprehension, and receptive vocabulary. Unpredicted growth from 1 to 8 y of age was also inversely associated with overage for grade (OR range across countries: 0.80–0.84) and positively associated with mathematics achievement (effect-size range: 0.05–0.10), reading comprehension (0.02–0.10), and receptive vocabulary (0.04–0.08). Children who recovered in linear growth had better outcomes than did children who were persistently stunted but were not generally different from children who experienced growth faltering. Conclusions: Improvements in child growth after early faltering might have significant benefits on schooling and cognitive achievement. Hence, although early interventions remain critical, interventions to improve the nutrition of preprimary and early primary school–age children also merit consideration.

Maternal mental health and child growth and development in four low and middle income countries

Objective Extend analyses of maternal mental health and infant growth in low- and middle-income countries (LMICs) to children through age eight years, and broaden analyses to cognitive and psychosocial outcomes. Design Community-based longitudinal cohort study in four LMICs (Ethiopia, India, Peru and Vietnam). Surveys and anthropometric assessments were carried out when the children were approximately ages 1, 5 and 8 years. Risk of maternal common mental disorders (rCMDs) was assessed with the Self-Reporting Questionnaire (SRQ)-20 (score ≥8). Setting Rural and urban as well as low- and middle-income communities. Participants 7722 mothers and their children. Main outcome measures Child stunting and underweight (Z score ≤2 of height and weight for age), and <20th centile for: cognitive development (Peabody Picture Vocabulary Test), and the psychosocial outcomes self pride and life satisfaction. Results A high rate of rCMD, stunting and underweight was seen in the cohorts. After adjusting for confounders, significant associations were found between maternal rCMDs and growth variables in the first year of life, with persistence to age 8 years in India and Vietnam, but not in the other countries. India and Vietnam also showed significant associations between rCMDs and lower cognitive development. After adjustment, rCMD was associated with low life satisfaction in Ethiopia but not in the other cohorts. Conclusions Associations of maternal rCMD in the first year of life with child outcomes varied across the study cohorts and, in some cases, persisted across the first 8 years of life of the child, and included growth, cognitive development and psychosocial domains.

Does household access to improved water and sanitation in infancy and childhood predict better vocabulary test performance in Ethiopian, Indian, Peruvian and Vietnamese cohort studies?

Objective Test associations between household water and sanitation (W&S) and childrens concurrent and subsequent Peabody Picture Vocabulary Test (PPVT) scores. Design Prospective cohort study. Setting Ethiopia, India, Peru, Vietnam. Participants 7269 children. Primary outcome measures PPVT scores at 5 and 8 years. Key exposure variables were related to W&S, and collected at 1, 5 and 8 years, including ‘improved’ water (eg, piped, public tap or standpipe) and ‘improved’ toilets (eg, collection, storage, treatment and recycling of human excreta). Results Access to improved water at 1 year was associated with higher language scores at 5 years (3/4 unadjusted associations) and 8 years (4/4 unadjusted associations). Ethiopian children with access to improved water at 1 year had test scores that were 0.26 SD (95% CI 0.17 to 0.36) higher at 5 years than children without access. Access to improved water at 5 years was associated with higher concurrent PPVT scores (in 3/4 unadjusted associations), but not later scores (in 1/4 unadjusted associations). 5-year-old Peruvian children with access to improved water had better concurrent performance on the PPVT (0.44 SD, 95% CI 0.30 to 0.59) than children without access to improved water. Toilet access at 1 year was also associated with better PPVT scores at 5 years (3/4 unadjusted associations) and sometimes associated with test results at 8 years (2/4 unadjusted associations). Toilet access at 5 years was associated with concurrent PPVT scores (3/4 unadjusted associations). More than half of all associations in unadjusted models (water and toilets) persisted in adjusted models, particularly for toilets in India, Peru and Vietnam. Conclusions Access to ‘improved’ water and toilets had independent associations with childrens PPVT scores that often persisted with adjustment for covariates. Our findings suggest that effects of W&S may go beyond subacute and acute infections and physical growth to include childrens language performance, a critical component of cognitive development.

Households across All Income Quintiles, Especially the Poorest, Increased Animal Source Food Expenditures Substantially during Recent Peruvian Economic Growth

Background Relative to plant-based foods, animal source foods (ASFs) are richer in accessible protein, iron, zinc, calcium, vitamin B-12 and other nutrients. Because of their nutritional value, particularly for childhood growth and nutrition, it is important to identify factors influencing ASF consumption, especially for poorer households that generally consume less ASFs. Objective To estimate differential responsiveness of ASF consumption to changes in total household expenditures for households with different expenditures in a middle-income country with substantial recent income increases. Methods The Peruvian Young Lives household panel (n = 1750) from 2002, 2006 and 2009 was used to characterize patterns of ASF expenditures. Multivariate models with controls for unobserved household fixed effects and common secular trends were used to examine nonlinear relationships between changes in household expenditures and in ASF expenditures. Results Households with lower total expenditures dedicated greater percentages of expenditures to food (58.4% vs.17.9% in 2002 and 24.2% vs. 21.5% in 2009 for lowest and highest quintiles respectively) and lower percentages of food expenditures to ASF (22.8% vs. 33.9% in 2002 and 30.3% vs. 37.6% in 2009 for lowest and highest quintiles respectively). Average percentages of overall expenditures spent on food dropped from 47% to 23.2% between 2002 and 2009. Households in the lowest quintiles of expenditures showed greater increases in ASF expenditures relative to total consumption than households in the highest quintiles. Among ASF components, meat and poultry expenditures increased more than proportionately for households in the lowest quintiles, and eggs and fish expenditures increased less than proportionately for all households. Conclusions Increases in household expenditures were associated with substantial increases in consumption of ASFs for households, particularly households with lower total expenditures. Increases in ASF expenditures for all but the top quintile of households were proportionately greater than increases in total food expenditures, and proportionately less than overall expenditures.

Stunting in Infancy Is Associated with Decreased Risk of High Body Mass Index for Age at 8 and 12 Years of Age

Background: Effects of early-life stunting on adiposity development later in childhood are not well understood, specifically with respect to age in the onset of overweight and obesity. Objectives: We analyzed associations of infant stunting with prevalence of, incidence of, and reversion from high body mass index–for-age z score (BMIZ) later in life. We then estimated whether associations of infant stunting with BMIZ varied by sex, indigenous status, and rural or urban residence. Methods: Data were collected from 1942 Peruvian children in the Young Lives cohort study at ages 1, 5, 8, and 12 y. Multivariable generalized linear models estimated associations of stunting (height-for-age z score <−2) at age 1 y with risk of BMIZ > 1 and BMIZ > 2 prevalence, incidence (moving above a BMIZ threshold between ages), and reversion (moving below a BMIZ threshold between ages) at later ages. Results: After adjustment for covariates, stunting at age 1 y was associated with a lower prevalence of BMIZ > 1 at age 8 y (RR: 0.81; 95% CI: 0.66, 1.00; P = 0.049) and 12 y (RR: 0.75; 95% CI: 0.61, 0.91; P = 0.004), as well as a lower prevalence of BMIZ > 2 at age 8 y. Stunting was not associated with incident risk of BMIZ > 1 or BMIZ > 2. Stunting was positively associated at age 5 y with risk of reversion from BMIZ > 1 (RR: 1.22; 95% CI: 1.05, 1.42; P = 0.008) and BMIZ > 2. We found evidence that the association of stunting with prevalent and incident BMIZ > 1 was stronger for urban children at ages 5 and 8 y, and for nonindigenous children at age 8 y. Conclusions: Stunting predicted a lower risk of prevalent BMIZ > 1 and BMIZ > 2, even after controlling for potential confounders. This finding may be driven in part by a higher risk of reversion from BMIZ > 1 by age 5 y. Our results contribute to an understanding of how nutritional stunting in infancy is associated with BMIZ later in life.

Intergenerational Transmission of Poverty and Inequality: Parental Resources and Schooling Attainment and Children’s Human Capital in Ethiopia, India, Peru, and Vietnam

Academic and policy literatures on intergenerational transmissions of poverty and inequality suggest that improving schooling attainment and income for parents in poor households will lessen poverty and inequality in their children’s generation through increased human capital accumulated by their children. However, magnitudes of such effects are unknown. We use data on children born in the twenty-first century in four developing countries to simulate how changes in parents’ schooling attainment and consumption would affect poverty and inequality in both the parents’ and their children’s generations. We find that increasing minimum schooling or income substantially reduces poverty and inequality in the parents’ generation but does not carry over to reducing poverty and inequality substantially in the children’s generation. Therefore, while reductions in poverty and inequality in the parents’ generation are desirable in themselves to improve welfare among current adults, they are not likely to have large impacts in reducing poverty and particularly in reducing inequality in human capital in the next generation.

Public versus Private: Evidence on Health Insurance Selection

This paper models health insurance choice in Chile (public versus private) as a dynamic, stochastic process, where individuals consider premiums, expected out-of pocket costs, personal characteristics and preferences. Insurance amenities and restrictions against pre-existing conditions among private insurers introduce asymmetry to the model. We confirm that the public system services a less healthy and wealthy population (adverse selection for public insurance). Simulation of choices over time predicts a slight crowding out of private insurance only for the most pessimistic scenario in terms of population aging and the evolution of education. Eliminating the restrictions on pre-existing conditions would slightly ameliorate the level (but not the trend) of the disproportionate accumulation of less healthy individuals in the public insurance program over time.

Adolescent mothers’ anthropometrics and grandmothers’ schooling predict infant anthropometrics in Ethiopia, India, Peru, and Vietnam

We investigated intergenerational associations of adolescent mothers’ and grandmothers’ anthropometrics and schooling with adolescent mothers’ offsprings anthropometrics in Ethiopia, India, Peru, and Vietnam. We examined birthweight (n = 283), birthweight Z‐score (BWZ), conditional growth in weight‐for‐age Z‐score (cWAZ, residuals from a regression of WAZ at last survey round on BWZ, sex, and age), and height‐for‐age Z‐score (HAZ) of children born to older cohort adolescent girls in the Young Lives study. Our key independent variables were adolescent mothers’ body size: HAZ and body‐mass‐index‐for‐age Z‐score (BMIZ) at age 8, conditional HAZ (cHAZ, residuals from a regression of HAZ at the end of a growth period on prior HAZ, age, and sex), conditional BMIZ growth (cBMIZ, calculated analogously), and grandmaternal BMIZ, HAZ, and schooling. We adjusted for child, maternal, and household characteristics. Adolescent mothers’ cHAZ (ages 8–15) predicted birthweight ( β = 130 g, 95% confidence interval (CI) 31–228), BWZ ( β = 0.31, CI 0.09–0.53), and cWAZ ( β = 0.28, CI 0.04–0.51). Adolescent mothers’ BMIZ at age 8 predicted birthweight ( β = 79 g, CI 16–43) and BWZ ( β = 0.22, CI 0.08–0.36). Adolescent mothers’ cBMIZ (ages 12–15) predicted child cWAZ and HAZ. Grandmothers’ schooling predicted grandchild birthweight ( β = 22 g, CI 1–44) and BWZ ( β = 0.05, CI 0.01–0.10).

Birth weight and prepubertal body size predict menarcheal age in India, Peru, and Vietnam

Evidence on the associations of birth weight and prepubertal nutritional status with menarcheal age for low‐ and middle‐income countries is limited. We investigated these relationships using the Young Lives younger cohort for 2001 Indian, Peruvian, and Vietnamese girls born in 2001–2002. Girls were followed at approximately ages 1, 5, 8, and 12 years. Weibull survival models estimated hazards of earlier menarche on the basis of birth weight Z‐scores (BWZ), and age‐8 BMI‐for‐age Z‐scores (BMIZ) and height‐for‐age Z‐scores (HAZ). Estimates controlled for potential individual‐, mother‐, and household‐level confounders and for changes in anthropometry between 1 and 8 years. In adjusted models, BWZ predicted later age at menarche (hazard ratio (HR) = 0.90, 95% CI: 0.83–0.97). Conversely, HAZ (HR = 1.66, 95% CI 1.5–1.83) and BMIZ at 8 years (HR = 1.28, 95% CI: 1.18–1.38) predicted earlier menarche. Changes in HAZ and BMIZ between 1 and 8 years were not associated with earlier menarche. Associations were consistent across countries, though with variation in estimated magnitudes. Maternal height and age were associated with later menarche. This evidence points to consistently robust and opposite associations of birth weight versus prepubertal attained height and body mass index with menarcheal age in three diverse settings with regard to nutrition, ethnicity, and socioeconomic status.