Kirk A. Dearden

The power of positive deviance

Identifying individuals with better outcome than their peers (positive deviance) and enabling communities to adopt the behaviours that explain the improved outcome are powerful methods of producing change

Children Who Recover from Early Stunting and Children Who Are Not Stunted Demonstrate Similar Levels of Cognition

Stunting is associated with adverse cognitive development in childhood and adolescence, fewer years of schooling, decreased productivity, and reduced adult stature. Recovery from early stunting is possible; however, few studies explore whether those who demonstrate linear catch-up growth experience long-term cognitive deficits. Using longitudinal data on 1674 Peruvian children from the Young Lives study, we identified factors associated with catch-up growth and assessed whether children who displayed catch-up growth have significantly lower cognition than children who were not stunted during infancy and childhood. Based on anthropometric data for children 6-18 mo of age and again for the same children when they were 4.5-6 y of age, we categorized participants as not stunted, stunted in infancy but not childhood (catch-up), stunted in childhood, and stunted in infancy and childhood. Children who had grandparents in the home, had less severe stunting in infancy, and had taller mothers were more likely to demonstrate catch-up growth by round 2. Children who experienced catch-up growth had verbal vocabulary and quantitative test scores that did not differ from children who were not stunted (P = 0.6 and P = 0.7, respectively). Those stunted in childhood as well as those stunted in infancy and childhood scored significantly lower on both assessments than children who were not stunted. Based on findings from this study, policy makers and program planners should consider redoubling efforts to prevent stunting and promote catch-up growth over the first few years of life as a way of improving childrens physical and intellectual development.

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.

Impact of early and concurrent stunting on cognition

Undernutrition is associated with poor cognitive development, late entry into school, decreased years of schooling, reduced productivity and smaller adult stature. We use longitudinal data from 1674 Peruvian children participating in the Young Lives study to assess the relative impact of early stunting (stunted at 6-18 months of age) and concurrent stunting (stunted at 4.5-6 years of age) on cognitive ability. Anthropometric data were longitudinally collected for children at 6-18 months of age and 4.5-6 years of age at which time verbal and quantitative ability were also assessed. We estimate that an increase in concurrent height-for-age z-scores (HAZ) by one standard deviation was associated with an increase in a childs score on the Peabody Picture Vocabulary Test (PPVT) by 2.35 points [confidence interval (CI): 1.55-3.15] and a 0.16 point increase on the cognitive development assessment (CDA) (CI: 0.05-0.27). Furthermore, we report that the estimate for concurrent HAZ and PPVT is significantly higher than the estimate for early stunting and PPVT. We found no significant difference between early and concurrent estimates for HAZ and CDA. Children from older mothers, children whose mothers had higher education levels, children living in urban areas, children who attended pre-school, children with fewer siblings and children from wealthier backgrounds scored higher on both assessments. Cognitive skills of children entering school were associated with early stunting but the strongest association was found with concurrent stunting suggesting that interventions preventing linear growth faltering should not only focus on the under 2s but include children up to 5 years of age.

Work outside the home is the primary barrier to exclusive breastfeeding in rural Viet Nam: insights from mothers who exclusively breastfed and worked

This study assessed barriers to exclusive breastfeeding in rural Viet Nam and identified how a few mothers were able to exclusively breastfeed despite barriers. A cross-sectional quantitative and qualitative assessment was carried out among 120 mothers of infants less than six months old in northern Viet Nam. Only 24% of the mothers exclusively breastfed. Adjusting for infants age and who attended delivery, the risk of not exclusively breastfeeding was 14.0 times greater for women who had returned to work than for women who had not. Exclusively breastfeeding mothers (n = 4) who worked differed from other mothers in important ways. They all felt they had enough milk, all knew the appropriate time to introduce foods and liquids, and most were supported in their breastfeeding decisions by commune health workers and family members. This research suggests strategies that can be implemented now to increase exclusive breastfeeding in rural work environments. These include improving knowledge about the introduction of water and semi-solids, addressing perceptions of milk insufficiency, securing support from others, and presenting mothers with options for exclusively breastfeeding, even when they work outside the home.

How representative are the surveillance, epidemiology, and end results (SEER) program cancer data of the United States?

AbstractObjective: Data from the 11s Surveillance, Epidemiology, and End Results tumor registries cover 14% of the US population and are often used to provide national estimates of cancer incidence and survival. Cancer mortality data for the US and for SEER are compared to assess the representation of SEER to the US. Methods: Comparisons between US and SEER cancer mortality were made for 16 of the leading causes of cancer death. Cancer site-specific comparisons were also made by race and sex. In addition, tobacco-related cancers were considered. Analyses were performed for the years when all 11 SEER registries were included in the SEER program. Poisson regression was used to estimate site-specific cancer mortality rate ratios between the US and SEER. Results: Cancer site-specific mortality rates derived from SEER data tend to under-represent the US cancer mortality experience for white males and females and black males. Under-representation is observed across the majority of SEER registries, with the highest amount of under representation in Utah and New Mexico. Under-representation of SEER data compared with US data is noticeably greater among tobacco-related cancers, particularly in Utah and New Mexico. Conclusion: For certain cancer sites, particularly tobacco-related cancers, the SEER coverage population is not representative of the US population.

An Integrated Child Nutrition Intervention Improved Growth of Younger, More Malnourished Children in Northern Viet Nam

Integrated nutrition programs are widely used to prevent and/or reverse childhood malnutrition, but rarely rigorously evaluated. The impact of such a program on the physical growth of young rural Vietnamese children was measured. We randomized six communes to receive an integrated nutrition program implemented by Save the Children. We matched six communes to serve as controls. Our sample consisted of 238 children (n = 119 per group) who were 5 to 30 months old on entry. Between December 1999 and December 2000, we measured weight and height monthly for six months and again at month 12. Principle outcomes were weight-for-age Z score (WAZ), height-for-age Z score (HAZ), and weight-for-height Z score (WHZ), and the changes among these measures. As expected, anthropometric indicators relative to international references worsened as the children aged. Overall, children in the intervention communes who were exposed to the integrated nutrition program did not show statistically significant better growth than comparison children. Intervention children who were younger (15 months or less) and more malnourished (less than −2 Z) at baseline, however, deteriorated significantly less than their comparable counterparts. Between baseline and month four, for example, intervention children who were malnourished and less than 15 months old at entry lost on average 0.05 WAZ while similar comparison children lost 0.25 WAZ (p = .02). Lack of overall impact on growth may be due to a lower than expected prevalence of malnutrition at baseline and/or deworming of comparison children. Targeting nutrition interventions at very young children will have the maximum impact on growth.

Growth faltering and recovery in children aged 1-8 years in four low- and middle-income countries: Young Lives

OBJECTIVE We characterized post-infancy child growth patterns and determined the incidence of becoming stunted and of recovery from stunting. DESIGN Data came from Young Lives, a longitudinal study of childhood poverty in four low- and middle-income countries. SETTING We analysed length/height measurements for children at ages 1, 5 and 8 years. SUBJECTS Children (n 7171) in Ethiopia, India, Peru and Vietnam. RESULTS Mean height-for-age Z-score (HAZ) at age 1 year ranged from -1·51 (Ethiopia) to -1·08 (Vietnam). From age 1 to 5 years, mean HAZ increased by 0·27 in Ethiopia (P < 0·001) and decreased among the other cohorts (range: -0·19 (Peru) to -0·32 (India); all P < 0·001). From 5 to 8 years, mean HAZ increased in all cohorts (range: 0·19 (India) to 0·38 (Peru); all P < 0·001). Prevalence of stunting (HAZ<-2·0) at 1 year ranged from 21 % (Vietnam) to 46 % (Ethiopia). From age 1 to 5 years, stunting prevalence decreased by 15·1 percentage points in Ethiopia (P < 0·001) and increased in the other cohorts (range: 3·0 percentage points (Vietnam) to 5·3 percentage points (India); all P ≤ 0·001). From 5 to 8 years, stunting prevalence decreased in all cohorts (range: 5·0 percentage points (Vietnam) to 12·7 percentage points (Peru); all P < 0·001). The incidence of becoming stunted between ages 1 to 5 years ranged from 11 % (Vietnam) to 22 % (India); between ages 5 to 8 years, it ranged from 3 % (Peru) to 6 % (India and Ethiopia). The incidence of recovery from stunting between ages 1 and 5 years ranged from 27 % (Vietnam) to 53 % (Ethiopia); between ages 5 and 8 years, it ranged from 30 % (India) to 47 % (Ethiopia). CONCLUSIONS We found substantial recovery from early stunting among children in four low- and middle-income countries.

Exploring the relationship between chronic undernutrition and asymptomatic malaria in Ghanaian children.

BackgroundA moderate association has been found between asymptomatic parasitaemia and undernutrition. However, additional investigation using the gold standard for asymptomatic parasitaemia confirmation, polymerase chain reaction (PCR), is needed to validate this association. Anthropometric measurements and blood samples from children less than five years of age in a rural Ghanaian community were used to determine if an association exists between chronic undernutrition and PCR-confirmed cases of asymptomatic malaria.MethodsThis was a descriptive cross-sectional study of 214 children less than five years of age from a community near Kumasi, Ghana. Blood samples and anthropometric measurements from these children were collected during physical examinations conducted in January 2007 by partners of the Barekuma Collaborative Community Development Programme.ResultsFindings from the logistic model predicting the odds of asymptomatic malaria indicate that children who experienced mild, moderate or severe stunting were not more likely to have asymptomatic malaria than children who were not stunted. Children experiencing anaemia had an increased likelihood (OR = 4.15; 95% CI: 1.92, 8.98) of asymptomatic malaria. Similarly, increased spleen size, which was measured by ultrasound, was also associated with asymptomatic malaria (OR = 2.17; 95% CI: 1.44, 3.28). Fast breathing, sex of the child, and age of the child were not significantly associated with the asymptomatic malaria.ConclusionsNo significant association between chronic undernutrition and presence of asymptomatic malaria was found. Children who experience anaemia and children who have splenomegaly are more likely to present asymptomatic malaria. Programmes aimed at addressing malaria should continue to include nutritional components, especially components that address anaemia.

Height-for-age z scores increase despite increasing height deficits among children in 5 developing countries

BACKGROUND Growth failure remains a persistent challenge in many countries, and understanding child growth patterns is critical to the development of appropriate interventions and their evaluation. The interpretation of changes in mean height-for-age z scores (HAZs) over time to define catch-up growth has been a subject of debate. Most studies of child growth have been cross-sectional or have focused on children through age 5 y. OBJECTIVE The aim was to characterize patterns of linear growth among individuals followed from birth into adulthood. DESIGN We compared HAZs and difference in height (cm) from the WHO reference median at birth, 12 mo, 24 mo, mid-childhood, and adulthood for 5287 individuals from birth cohorts in Brazil, Guatemala, India, the Philippines, and South Africa. RESULTS Mean HAZs were <0 at birth in the 3 cohorts with data and ranged from -0.6 (Brazil) to -2.9 (Guatemala) at age 24 mo. Between 24 mo and mid-childhood, HAZ values increased by 0.3-0.5 in South Africa, Guatemala, and the Philippines and were unchanged in Brazil and India. Between mid-childhood and adulthood, mean HAZs increased in all cohorts but remained <0 in adulthood [mean range: -0.3 (Brazil) to -1.8 (Guatemala and Philippines)]. However, from 24 mo to adulthood, height differences from the reference median became greater. CONCLUSIONS From age 2 y to adulthood, mean HAZs increased, even though height deficits relative to the reference median also increased. These 2 metrics may result in different interpretations of the potential for and the impact of catch-up growth in height.