Association of breastfeeding and stunting in Peruvian toddlers: an example of reverse causality

Correlates of early child development among children with stunting: A cross-sectional study in Uganda

Many children in low- and middle-income countries are not attaining their developmental potential. Stunting is associated with poor child development, but it is not known which correlates of stunting are impairing child development. We explored potential socioeconomic, nutritional, clinical, and household correlates of early child development among 12-59-month-old children with stunting in a cross-sectional study in Uganda. Development was assessed using the Malawi Development Assessment Tool (MDAT) across four domains of gross and fine motor, language, and social skills. Linear regression analysis was used to assess correlates of development in the four domains and total MDAT score. Of 750 children included, the median [interquartile range] age was 30 [23-41] months, 55% of the children resided in rural settings with 21% from female-headed households and 47% of mothers had no schooling. The mean ± standard deviation height-for-age z-score (HAZ) was -3.02 ± 0.74, 40% of the children had a positive malaria test and 65% were anaemic (haemoglobin < 110 g/L). One-third had children's books at home, majority (96%) used household objects to play with and most of them (70%) used toys as pretence items like those to mimic cooking. After age, sex, and site adjustments, HAZ (0.24, 95% confidence interval [CI]: 0.14-0.33) and head circumference (0.07, 95% CI: 0.02-0.12) were positive correlates of total MDAT score, whereas weight-for-height z-score (WHZ) was not. Current breastfeeding was associated with 0.41 (95% CI: 0.17-0.65) lower total MDAT score. Children from households with a single income earner had 0.22 (95% CI: 0.06-0.37) lower total MDAT score. Furthermore, severe food insecurity, inflammation and positive malaria test were associated with lower scores for motor development. All family care indicator subscales (FCIs) positively correlated with the total MDAT score and this association was independent of household's socioeconomic status. In conclusion, stunting degree, head circumference, number of household income earners and stimulation by improved FCIs correlate with early child development among stunted children. The negative association with prolonged breastfeeding is likely due to reverse causality. Identified correlates may inform initiatives to support children with stunting attain their development potential.

Factors associated with exclusive breastfeeding of children under six months of age in Cote d'Ivoire

BACKGROUND

Despite benefits of exclusive breastfeeding (EBF) and its strategic place in the national guidelines for infant and young child feeding, its practice remains insufficient in Cote d'Ivoire. It is therefore important to identify its early stopping associated factors. We aimed to (i) assess the extent of children's exposure to exclusive breastfeeding and the associated explanatory factors for discontinuation before six months, and (ii) to profile non-exclusively breastfed children and interrelationships between these factors.

METHODS

A secondary analysis of data from the 2016 Cote d'Ivoire Fifth Multi Indicator Cluster Survey (MICS5) of 980 children under six months of age was conducted in this study. Data were analyzed using the actuarial method of survival hazard estimation combined with the Wilcoxon (Gehan) test, discrete time proportional hazards regression models, and Multiple Correspondence Analysis (MCA) to profile the children.

RESULTS

Maternal exposure to counseling session, age at delivery, and child sex were significantly associated with the likelihood of discontinuing exclusive breastfeeding before the first six months of life. Children deprived of EBF resided in urban areas, in high and very high economic welfare households. Their mothers had a secondary education or higher and had three or fewer children. Logistic analysis showed that health status and sex of the child were significantly associated (P < 0.001) with exclusive breastfeeding. An extremely important and rarely studied factor is that children who were sick in weeks prior to the survey were more likely to remain exclusive breastfeeding (adjusted OR 1.80; 95% Confidence Interval (CI) 1.452, 2.234). Girls are less likely to be exclusively breastfed than boys (adjusted OR 1.48; 95% CI 1.22, 1.798). Low standard of living was associated with early cessation of EBF (adjusted OR 2.15; CI 1.325, 3.499). The duration of the exclusive breastfeeding was significantly longer among mothers with high exposure to medical discourse (adjusted OR 0.74; CI 0.595, 0.91).

CONCLUSIONS

Improving the practice of exclusive breastfeeding in Cote d'Ivoire requires strengthening the capacities of health professionals in terms of advice and assistance to mothers for the practice of exclusive breastfeeding and its maintenance until six months of age, regardless of the health status and sex of the child.

Determinants of length for age Z scores among children aged 6-23 months in Central Java, Indonesia: a path analysis

Introduction

Length for Age Z (LAZ) score determinants are complex and vary among different areas, but it is important for designing effective and efficient strategies to decrease stunting prevalence among children under 2 years. This study aimed to investigate the determinants of LAZ scores among children under 2 years in Central Java, Indonesia.

Methods

This study was conducted on the 2021 Indonesian Nutritional Status Study (INSS) dataset, which was a cross-sectional survey. Data on 3,430 children aged 6-23 months from Central Java province were derived from the 2021 INSS data. After missing data elimination, 3,238 subjects were included in the analysis. Determinant factors included direct and indirect factors. Direct factors were the mother's age, birth weight Z score (BWZ), birth length Z score (BLZ), exclusively breastfed history, dietary diversity scores (DDS), empty calorie drink consumption, unhealthy snacks consumption, and infections. Indirect factors were early initiation of breastfeeding (EIBF) and posyandu (integrated health post) utilization. Underlying factors were socioeconomic status (SES) and the mother's education. Bivariate analyses and multiple linear regressions were conducted. A path analysis with a hypothesized model based on the UNICEF conceptual framework was also performed.

Results

Stunting, wasting and underweight proportions among the subjects were 19.1%, 7.6% and 12.3%, respectively. The mean LAZ scores were -0.95 ± 1.22; the mother's age was 29.7 ± 5.95 years; BWZ was -0.47 ± 0.97; BLZ was -0.55 ± 1.05; and DDS was 4.45 ± 1.51. The infection proportion among the subjects was 28%. BWZ and BLZ were positively correlated to LAZ scores, with r = 0.267 (p < 0.01) and r = 0.260 (p < 0.01), respectively. The mother's age was negatively correlated to LAZ scores with r = -0.041 (p < 0.05). Maternal education was positively correlated to SES but had no direct effect on LAZ scores. LAZ score determinants of BLZ (p < 0.001) and SES (p < 0.001) showed positive direct associations with LAZ scores, but the mother's age (p = 0.039), exclusively breastfed history (p < 0.001), and empty calorie drinks consumption (p < 0.001) had negative associations with LAZ scores.

Conclusion

To prevent stunting among children aged 6-23 months in Central Java, Indonesia, intervention programs to increase the nutritional status of women at child-bearing age and nutrition education on child feeding practices should be conducted more efficiently and effectively.

Maternal socioeconomic status and infant feeding practices underlying pathways to child stunting in Cambodia: structural path analysis using cross-sectional population data

OBJECTIVES

To identify and investigate complex pathways to stunting among children aged 6-24 months to determine the mediating effects of dietary diversity and continued breast feeding on the association between socioeconomic factors and child stunting.

DESIGN, SETTING AND PARTICIPANTS

We analysed the most recent cross-sectional Demographic and Health Survey data from Cambodia (2014). We applied structural path analysis on a sample of 1365 children to model the complex and inter-related pathways of factors determining children's height for age. Explanatory variables included a composite indicator of maternal employment, household wealth, maternal education, current breastfeeding status and dietary diversity score. Results are presented both in terms of non-standardised and standardised coefficients.

OUTCOME MEASURE

The primary outcome measure was height-for-age Z-scores as a continuous measure.

RESULTS

Findings suggest that children's dietary diversity and continued breast feeding mediate the association between socioeconomic status and children's height. While there was no significant direct effect of maternal education on children's height, results suggested significant indirect pathways through which maternal education effects children's height; operating through household wealth, maternal employment, dietary diversity and continued breastfeeding status (p&lt;0.001). Most notably, 41% of the effect of maternal employment on children's height was mediated by either dietary diversity or continued breast feeding.

CONCLUSION

We provide evidence to support targeted nutrition interventions which account for the different ways in which underlying socioeconomic factors influence infant and young child feeding practices, and the potential impact on child nutritional status.

Exploration of Stunting Events as an Effort to Prevent Stunting in Bangkalan Regency

BACKGROUND: The result of Health Research (Riskesdas) in 2018 showed a decrease in the prevalence of stunting at the national average of 6.4% over a period of 5 years, that is, from 37.2% (2013) to 30.8% (2018). The prevalence of stunting in children under five in Bangkalan was the highest in East Java. Data on the Nutrition Status Monitoring of East Java in 2015 showed that the prevalence of stunting in Bangkalan reached 53.2%; consisting of 27.4% of severely stunted children and 25.8% of stunted children. AIM: This study determined factors that influenced the stunting prevalence in the Bangkalan Regency. METHODS: The method of this study was exploratory qualitative research that determined dominant factors influencing the stunting prevalence in Bangkalan Regency and developed a theme analysis instrument. Data were collected through interviews done with 12 health workers in charge of stunting eradication programs. RESULTS: The results and discussions showed that stunting prevalence in Bangkalan Regency remained high that it requires a thorough study to determine the factors influencing it. Results of this study showed that cultural factors shaped how local community in Bangkalan Regency viewed maternity care and parenting styles. From the FGD analysis, stunting programs such as the 1000 first days of life program have been implemented, yet cross-community collaboration was not yet established. It also requires a synergy among health agencies, education agencies, and villages to include contents about stunting eradication programs in all public activities. CONCLUSION: Suggestions were proposed regarding the need to emphasize the importance of cross-sectoral and cross-program cooperation in controlling and reducing the stunting rate. Midwives as officials of Posyandu (Regular Health Care) need to improve the coordination with the local community and emphasize the promotion of stunting eradication programs.

Basic determinants of child linear growth outcomes in sub-Saharan Africa: a cross-sectional survey analysis of positive deviants in poor households

Childhood malnutrition is a significant public health problem confronting countries across the globe. Although there is evidence of a downward trend in undernutrition globally, sub-Saharan Africa did not experience significant improvement in the past decades. This study investigated the basic determinants of linear growth among children living in poor households. We analysed a nationally representative sample of children aged 0–59 months (N = 24,264). The study countries were Ghana, Kenya, the Democratic Republic of Congo (DRC), Nigeria, and Mozambique. The child’s height-for-age Z-scores (HAZ), categorised into HAZ > − 2 standard deviations (SD) (not stunted) and HAZ < − 2 SD (stunted) was the outcome variable of interest. We used logistic regression as our analytical strategy. In DRC, Ghana, Kenya and Nigeria, maternal years of schooling was associated with positive linear growth among children living in poor households. In Ghana and DRC, four antenatal visits had a positive effect on better linear growth, while in Nigeria, healthy maternal body mass index (kg/m²) had a positive effect on child's linear growth. The putative socio-demographic determinants investigated in our study can promote the linear growth of children living in poor households. Interventions aimed at fostering linear growth among children living in poverty should focus on enhancing these factors.

Child stunting starts in utero: Growth trajectories and determinants in Ugandan infants

Childhood stunting remains a public health burden worldwide. Although many studies have examined early life and in‐utero risk factors; most have been observational and have used analytic techniques that make inferences limited to population means, thereby obscuring important within‐group variations. This study addressed that important gap. Using data from a birth cohort of Ugandan infants (n = 4528), we applied group‐based trajectory modelling to assess diverse patterns of growth among children from birth to 1‐year old. A multinomial regression model was conducted to understand the relationship between risk factors and observed patterns across groups. We found that the onset of stunting occurred before birth and followed four distinct growth patterns: chronically stunted (Group 1), recovery (Group 2), borderline stunted (Group 3) and normal (Group 4). The average length‐for‐age z‐score (LAZ) at birth was −2.6, −3.9, −0.6 and 0.5 for Groups 1–4, respectively. Although both Groups 1 and 2 were stunted at birth, stunting persisted in Group 1 while children in Group 2 recovered by the fourth month. Group 3 exhibited mild stunting while Group 4 was normal. Wasting and underweight were observed in all groups, with the highest prevalence of underweight in Group 1. Wasting gradually increased among children born already stunted (Groups 1 and 2). This showed the importance of distinguishing children by their growth patterns rather than aggregating them and only comparing population averages against global growth standards. The design of nutrition interventions should consider the differential factors and potential for growth gains relative to different risks within each group.

In a sample of Ugandan infants, the onset of stunting occurred in utero and set in motion a range of possible growth trajectories for the child after birth.

Child growth can be characterised by diverse patterns that suggest temporal variations in children's growth. This provides an opportunity for policymakers to provide specialised and targeted nutrition interventions.

Addressing low birth weight, preterm births and small‐for‐gestational‐age is critical to effectively reduce rates of stunting in rural Uganda.

Health care provider support and factors associated with breastfeeding beyond infancy: A cross-national study

BACKGROUND

Breastfeeding beyond infancy (12 months) remains atypical in the United States, United Kingdom, Canada, and Australia, and the role of health care providers is unclear. The objective of this study was to compare women's perceptions of provider support and other factors affecting breastfeeding beyond infancy across countries, among women who had each successfully breastfed at least one child that long.

METHODS

Women completed an online questionnaire distributed via La Leche League, USA (2013), about sources and ratings of support for breastfeeding for their oldest child who was breastfed at least 12 months and participant demographics. Multivariable log-binomial regression was used to compare ratings of health care provider support and the importance of 13 factors by country.

RESULTS

Some similarities and many differences were observed across countries in support received from providers, whereas modest or no differences were observed in the importance women placed on factors like health benefits and enjoyment of breastfeeding. Of 59 581 women, less than half discussed their decision to breastfeed beyond infancy with their child's provider. United Kingdom women rated their comfort in discussing breastfeeding beyond 12 months with their providers and the support received as lower than United States women. Canadian women gave lower ratings than United States women, but inconsistently. Australian women rarely differed from United States women in their responses. Providers' recommendations were not important to the decision to breastfeed beyond infancy, especially for United Kingdom women.

DISCUSSION

Rates of breastfeeding beyond infancy are low in these countries; improving provider support may help achieve global breastfeeding goals.

Risk factors for early childhood growth faltering in rural Cambodia: a cross-sectional study

OBJECTIVE

This study aimed to determine risk factors of growth faltering by assessing childhood nutrition and household water, sanitation, and hygiene (WASH) variables and their association with nutritional status of children under 24 months in rural Cambodia.

DESIGN

We conducted surveys in 491 villages (clusters) randomised across 55 rural communes in Cambodia in September 2016 to measure associations between child, household and community-level risk factors for stunting and length-for-age z-score (LAZ). We measured 4036 children under 24 months of age from 3877 households (491 clusters). We analysed associations between nutrition/WASH practices and child growth (LAZ, stunting) using generalised estimating equations (GEEs) to fit linear regression models with robust SEs in a pooled analysis and in age-stratified analyses; child-level and household-level variables were modelled separately from community-level variables.

RESULTS

After adjustment for potential confounding, we found household-level and community-level water, sanitation and hygiene factors to be associated with child growth among children under 24 months: presence of water and soap at a household's handwashing station was positively associated with child growth (adjusted mean difference in LAZ +0.10, 95% CI 0.03 to 0.16); household-level use of an improved drinking water source and adequate child stool disposal practices were protective against stunting (adjusted prevalence ratio (aPR) 0.80, 95% CI 0.67 to 0.97; aPR 0.82, 95% CI 0.64 to 1.03). In our age-stratified analysis, we found associations between child growth and community-level factors among children 1-6 months of age: shared sanitation was negatively associated with growth (-0.47 LAZ, 95% CI -0.90 to -0.05 compared with children in communities with no shared facilities); improved sanitation facilities were protective against stunting (aPR 0.43, 95% CI 0.21 to 0.88 compared with children in communities with no improved sanitation facilities); and open defecation was associated with more stunting (aPR 2.13, 95% CI 1.10 to 4.11 compared with children in communities with no open defecation). These sanitation risk factors were only measured in the youngest age strata (1-6 months). Presence of water and soap at the household level were associated with taller children in the 1-6 month and 6-12 month age strata (+0.10 LAZ, 95% CI -0.02 to 0.22 among children 1-6 months of age; +0.11 LAZ, 95% CI -0.02 to 0.25 among children 6-12 months of age compared with children in households with no water and soap). Household use of improved drinking water source was positively associated with growth among older children (+0.13 LAZ, 95% CI -0.01 to 0.28 among children 12-24 months of age).

CONCLUSION

In rural Cambodia, water, sanitation and hygiene behaviours were associated with growth faltering among children under 24 months of age. Community-level sanitation factors were positively associated with growth, particularly for infants under 6 months of age. We should continue to make effort to: investigate the relationships between water, sanitation, hygiene and human health and expand WASH access for young children.

Mediators of differences by parental education in weight-related outcomes in childhood and adolescence in Norway

Studies exploring mediators of socioeconomic inequalities in excess weight gain in early-life and subsequent overweight/obesity (OW/OB) among youth are limited. Thus, this study examined the mediating role of prenatal and early postnatal factors and child energy balance-related behaviours (EBRB) in the effects of parental education on (i) excess weight gain from birth to 2 years and (ii) OW/OB at 5, 8 and 14 years. The Norwegian Mother, Father and Child Cohort Study was used to include participants at the ages of 2 (n = 59,597), 5 (n = 27,134), 8 (n = 28,285) and 14 (n = 11,278) years. Causal mediation analyses using the inverse odds weighting approach were conducted. Children of low-educated parents had a higher conditional excess weight gain at 2 years compared to children of high-educated parents (total effect, RRTE = 1.06; 95% CI 1.01, 1.10). The joint mediation effects of the prenatal and early postnatal factors explained most of the total effect of low education on conditional excess weight gain at 2 years. Children of low-educated parents had a higher risk of OW/OB at 5, 8 and 14 years compared to children of high-educated parents. The mediators jointly explained 63.7%, 67% and 88.9% of the total effect of parental education on OW/OB among 5, 8 and 14 year-old-children, respectively. Of the total mediated effects at 5, 8 and 14 years, the prenatal and early postnatal mediators explained 59.2%, 61.7% and 73.7%, whereas the child EBRB explained 10.3%, 15.8.0%% and 34.8%. The mediators included were found to have a considerable mediating effect in the associations explored, in particular the prenatal and early postnatal factors. If truly causal, the findings could indicate potential targets for interventions to tackle socioeconomic inequalities in OW/OB from birth to adolescence.

Breastfeeding, feeding practices and stunting in indigenous Ecuadorians under 2 years of age

Background

The indigenous child population in Ecuador has a high prevalence of stunting. There is limited evidence of the association between breastfeeding, feeding practices, and stunting in indigenous children. This study aimed to analyze the prevalence of breastfeeding and complementary feeding practices and explore their association with stunting in Ecuadorian indigenous children under two years of age.

Methods

Cross-sectional study of secondary data analysis using the 2012 Ecuador National Health and Nutrition Study, in 625 children aged 0–23 months (48,069 expanded sample), representative for the indigenous population. Breastfeeding and complementary feeding indicators were analyzed by age groups. Timely initiation of breastfeeding (within one hour after birth), exclusive breastfeeding (infants under six months who received only breast milk for the previous day), and other indicators were measured. Chi-square test or Fisher's exact test and logistic regression for complex samples were used to explore association with demographic and socioeconomic factors and stunting.

Results

Twenty-six-point eight percent of the children were stunted. Stunting occurred mainly in children with rural residence, on poor households, and where there were four or more children. Most of the children had a timely initiation of breastfeeding (69.5% for 0–12 months and 75.5% for 13–23 months) and exclusive breastfeeding up to six months (78.2%). Among children between 6–12 months of age, 99.3% continued to be breastfed. In children from ages 6 to 12 months, 32.5% received food with adequate dietary diversity. Lower percentages of complementary feeding occurred in the poorest, adolescent mothers or those with less education. Children who did not receive the minimum frequency of meals for their age had higher odds of stunting (OR 3.28; 95% CI 1.3, 8.27). Children from age 19 to 23 months who consumed foods rich in iron showed lower probabilities of stunting (OR 0.04; 95% CI 0.00, 0.51).

Conclusions

Breastfeeding practices reached a prevalence of 70% or more, without being associated with stunting. Complementary feeding practices showed differences by socioeconomic condition. Not reaching the minimum meal frequency between 6 and 12 months of age was associated with stunting. Plans and strategies are necessary to promote adequate feeding and breastfeeding practices in the indigenous population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13006-022-00461-0.

Associations between the infant and young child feeding index and nutritional status

BACKGROUND

The infant and child feeding index (ICFI) is a single summary World Health Organization influenced index to assess feeding quality in infants and young children aged 6-36 months. This study aimed to demonstrate any associations between ICFI and nutritional status in a single Thai center.

METHODS

The demographic data and feeding practices of healthy infants and children aged 6-36 months were collected from questionnaires given to 304 parents/caregivers; anthropometric measurements were taken. Associations between ICFI and weight-for-age Z scores (WAZ), length/height for age Z scores (LAZ/HAZ), weight-for-length/height Z scores (WLZ/WHZ), and body mass index-for-age Z scores (BAZ) were examined.

RESULTS

The mean ICFI was 6.14 ± 1.63 and was lowest in the 6-8 months age group. Breastfed infants had significantly higher ICFI scores than those not breastfed. Factors influencing ICFI were infant age and milk volume intake. The ICFI was negatively associated with WAZ, WLZ/WHZ, and BAZ (β = -0.13, P = 0.037; β = -0.17, p = 0.01; β = -0.15, P = 0.026, respectively). Breastfeeding was also negatively associated with WAZ, LAZ/HAZ, WLZ/WHZ, and BAZ.

CONCLUSIONS

This study demonstrated a negative association between the ICFI and nutritional status. Breastfeeding may have obscured some positive effects from appropriate feeding practices, while dairy consumption may have hidden negative outcome from inappropriate ones. Despite the ICFI appearing to reflect infant and young child feeding behaviors, using the ICFI alone may not accurately reveal nutritional status.

Effectiveness of peer counseling and membership in breastfeeding support groups in promoting optimal breastfeeding behaviors in the Philippines

Background

The prevalence of early initiation of breastfeeding and exclusive breastfeeding (EBF) at 6 months remain low in the Philippines. To help meet the 90% early initiation of breastfeeding target and to improve infant and young child feeding practices in the Philippines, the Millennium Development Goals - Fund 2030 Joint Programme (JP) on Ensuring Food Security and Nutrition for Children 0–24 months old was implemented. We aimed to determine the effectiveness of visits by peer counselors during pregnancy and after delivery, and membership in breastfeeding support groups in promoting these optimal breastfeeding practices.

Methods

We used data from the Endline Survey of the JP to study the effects of prenatal and postnatal peer counselor visits, and membership in breastfeeding support groups, and their possible interactions with initiation of breastfeeding within 1 hour of birth among children aged 0 to 24 months and EBF at 6 months among children aged 6 to 24 months, while adjusting for confounding. We used logistic regression methods for survey data to assess these associations.

Results

Of the 2343 mother-infant pairs, only 1500 (63.1%) practiced early initiation of breastfeeding. Of the 1865 children aged 6 months or older, only 621 (34.7%) were exclusively breastfed at 6 months. After adjusting for confounding variables, there was no strong evidence that peer counselor visits were associated with early initiation or EBF at 6 months. However, members of breastfeeding support groups had 1.49 times higher odds of early initiation of breastfeeding (95% CI [Confidence Interval] 1.12, 1.98) and 1.65 times higher odds of EBF (95% CI 1.20, 2.24) compared to those who were not members of breastfeeding support groups. There was no interaction between the different exposure variables and early initiation and EBF at 6 months.

Conclusions

Our findings suggest breastfeeding support groups may be institutionalized to promote both early initiation of breastfeeding and EBF in the Philippines, while the role of peer counselors in promoting optimal breastfeeding behaviors should be further reviewed. Our suggestion to integrate non-healthcare professionals to promote early initiation of breastfeeding and EBF could be tested in future intervention studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13006-021-00400-5.

Breastfeeding Beyond 12 Months: Is There Evidence for Health Impacts?

Because breastfeeding provides optimal nutrition and other benefits for infants (e.g., lower risk of infectious disease) and benefits for mothers (e.g., less postpartum bleeding), health organizations recommend that healthy infants be exclusively breastfed for 4 to 6 months in the United States and 6 months internationally. Recommendations related to how long breastfeeding should continue, however, are inconsistent. The objective of this article is to review the literature related to evidence for benefits of breastfeeding beyond 1 year for mothers and infants. In summary, human milk represents a good source of nutrients and immune components beyond 1 year. Some studies point toward lower infant mortality in undernourished children breastfed for >1 year, and prolonged breastfeeding increases interbirth intervals. Data on other outcomes (e.g., growth, diarrhea, obesity, and maternal weight loss) are inconsistent, often lacking sufficient control for confounding variables. There is a substantial need for rigorous, prospective, mixed-methods, cross-cultural research on this topic. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Do Early Infant Feeding Practices and Modifiable Household Behaviors Contribute to Age-Specific Interindividual Variations in Infant Linear Growth? Evidence from a Birth Cohort in Dhaka, Bangladesh

BACKGROUND

Causes of infant linear growth faltering in low-income settings remain poorly understood. Identifying age-specific risk factors in observational studies might be influenced by statistical model selection.

OBJECTIVES

To estimate associations of selected household factors and infant feeding behaviors within discrete age intervals with interval-specific changes in length-for-age z-scores (LAZs) or attained LAZ, using 5 statistical approaches.

METHODS

Data from a birth cohort in Dhaka, Bangladesh (n = 1157) were analyzed. Multivariable-adjusted associations of infant feeding patterns or household factors with conditional LAZ (cLAZ) were estimated for 5 intervals in infancy. Two alternative approaches were used to estimate differences in interval changes in LAZ, and differences in end-interval attained LAZ and RRs of stunting (LAZ < -2) were estimated.

RESULTS

LAZ was symmetrically distributed with mean ± SD = -0.95 ± 1.02 at birth and -1.00 ± 1.04 at 12 mo. Compared with exclusively breastfed infants, partial breastfeeding (difference in cLAZ: -0.11; 95% CI: -0.20, -0.02) or no breastfeeding (-0.30; 95% CI: -0.54, -0.07) were associated with slower growth from 0 to 3 mo. However, associations were not sustained beyond 6 mo. Modifiable household factors (smoking, water treatment, soap at handwashing station) were not associated with infant growth, attained size, or stunting. Alternative statistical approaches yielded mostly similar results as conditional growth models.

CONCLUSIONS

The entire infant LAZ distribution was shifted down, indicating that length deficits were mostly caused by ubiquitous or community-level factors. Early-infant feeding practices explained minimal variation in early growth, and associations were not sustained to 12 mo of age. Statistical model choice did not substantially alter the conclusions. Modifications of household hygiene, smoking, or early infant feeding practices would be unlikely to improve infant linear growth in Bangladesh or other settings where growth faltering is widespread.

Relationship between breastfeeding duration and undernutrition conditions among children aged 0-3 Years in Pakistan

Background

The World Health Organization recommends that a child should be breastfed up to 2 years of age as it is essential for proper growth and development but population-based studies around the world have found conflicting results on the subject. Our study aims to analyze whether there is a relationship between the duration of breastfeeding and undernutrition among children aged from birth up to 3 years of age in Pakistan.

Methods

A secondary analysis of the Pakistan Demographic and Health Survey 2013-2014 with 1072 children aged 3 years and under was conducted. The relationship between breastfeeding duration and undernutrition status was estimated through multiple logistic regression analysis.

Results

The prevalence of stunting, wasting and underweight were 40.6%, 15.8% and 33.9% respectively, while prevalence of severe stunting is at 22.5%; severe wasting at 4.5% and severe underweight at 12.2% in children in our study. Odds of being stunted were significantly higher for children in their 3rd year of life [AOR: 4.35, CI 95% = (2.01, 9.33)] compared to children being breastfed in their 2nd year of life [AOR: 2.43, CI 95% = (1.55, 3.79) after being adjusted for maternal, child, demographic and healthcare access variables. Similarly, children being breastfed in their third year of life were more susceptible to developing severe stunting [AOR: 6.19, CI 95% = (3.31, 11.56)] in comparison to children in their second year [AOR: 2.84, CI 95% = (1.81, 4.46)]. There was no significant association between breastfeeding and wasting/severe wasting, or between breastfeeding and underweight/severe underweight.

Conclusion

Breastfeeding in the 2nd and 3rd year of life was found to have significant relationship with stunting and severe stunting. Mothers need to be educated about the risks of prolonged breastfeeding to reduce the burden of undernutrition in the country.

Socio-demographic factors associated with normal linear growth among pre-school children living in better-off households: A multi-country analysis of nationally representative data

This study examined the socio-demographic factors associated with normal linear growth among pre-school children living in better-off households, using survey data from Ghana, Kenya, Nigeria, Mozambique and Democratic Republic of Congo (DRC). The primary outcome variable was child height-for-age z-scores (HAZ), categorised into HAZ≥-2SD (normal growth/not stunted) and HAZ<-2 (stunted). Using logistic regression, we estimated adjusted odds ratios (aORs) of the factors associated with normal growth. Higher maternal weight (measured by body mass index) was associated with increased odds of normal growth in Mozambique, DRC, Kenya and Nigeria. A unit increase in maternal years of education was associated with increased odds in normal growth in DRC (aOR = 1.06, 95% CI = 1.03, 1.09), Ghana (aOR = 1.08, 95% CI = 1.04, 1.12), Mozambique (aOR = 1.08, 95% CI = 1.05, 1.11) and Nigeria (aOR = 1.07, 95% CI = 1.06, 1.08). A year increase in maternal age was positively associated with normal growth in all the five countries. Breastfeeding was associated with increased odds of normal growth in Nigeria (aOR = 1.30, 95% CI = 1.16, 1.46) and Kenya (aOR = 1.37, 95% CI = 1.05, 1.79). Children of working mothers had 25% (aOR = 0.75, 95% CI = 0.60, 0.93) reduced odds of normal growth in DRC. A unit change in maternal parity was associated with 10% (aOR = 0.90, 95% CI = 0.84, 0.97), 23% (aOR = 0.77, 95% CI = 0.63, 0.93), 25% (aOR = 0.75, 95% CI = 0.69, 0.82), 6% (aOR = 0.94, 95% CI = 0.89, 0.99) and 5% (aOR = 0.95, 95% CI = 0.92, 0.99) reduced odds of normal growth in DRC, Ghana, Kenya, Mozambique and Nigeria, respectively. A child being a male was associated with 18% (aOR = 0.82, 95% CI = 0.68, 0.98), 40% (aOR = 0.60, 95% CI = 0.40, 0.89), 37% (aOR = 0.63, 95% CI = 0.51, 0.77) and 21% (aOR = 0.79, 95% CI = 0.71, 0.87) reduced odds of normal child growth in DRC, Ghana, Kenya and Nigeria, respectively. In conclusion, maternal education, weight, age, breastfeeding and antenatal care are positively associated with normal child growth. In contrast, maternal parity, employment, and child sex and age are associated negatively with normal growth. Interventions to improve child growth should take into account these differential effects.

Association Between Parental Income During Childhood and Risk of Schizophrenia Later in Life

IMPORTANCE

Evidence linking parental socioeconomic position and offspring's schizophrenia risk has been inconsistent, and how risk is associated with parental socioeconomic mobility has not been investigated.

OBJECTIVE

To elucidate the association between parental income level and income mobility during childhood and subsequent schizophrenia risk.

DESIGN, SETTING, AND PARTICIPANTS

National cohort study of all persons born in Denmark from January 1, 1980, to December 31, 2000, who were followed up from their 15th birthday until schizophrenia diagnosis, emigration, death, or December 31, 2016, whichever came first. Data analyses were from March 2018 to June 2019.

EXPOSURE

Parental income, measured at birth year and at child ages 5, 10, and 15 years.

MAIN OUTCOMES AND MEASURES

Hazard ratios (HRs) for schizophrenia were estimated using Cox proportional hazard regression. Cumulative incidence values (absolute risks) were also calculated.

RESULTS

The cohort included 1 051 033 participants, of whom 51.3% were male. Of the cohort members, 7544 (4124 [54.7%] male) were diagnosed with schizophrenia during 11.6 million person-years of follow-up. There was an inverse association between parental income level and subsequent schizophrenia risk, with children from lower income families having especially elevated risk. Estimates were attenuated, but risk gradients remained after adjustment for urbanization, parental mental disorders, parental educational levels, and number of changes in child-parent separation status. A dose-response association was observed with increasing amount of time spent in low-income conditions being linked with higher schizophrenia risk. Regardless of parental income level at birth, upward income mobility was associated with lower schizophrenia risk compared with downward mobility. For example, children who were born and remained in the lowest income quintile at age 15 years had a 4.12 (95% CI, 3.71-4.58) elevated risk compared with the reference group, those who were born in and remained in the most affluent quintile, but even a rise from the lowest income quintile at birth to second lowest at age 15 years appeared to lessen the risk elevation (HR, 2.80; 95% CI, 2.46-3.17). On the contrary, for those born in the most affluent quintile, downward income mobility between birth and age 15 years was associated with increased risks of developing schizophrenia.

CONCLUSIONS AND RELEVANCE

This study's findings suggest that parental income level and income mobility during childhood may be linked with schizophrenia risk. Although both causation and selection mechanisms could be involved, enabling upward income mobility could influence schizophrenia incidence at the population level.

Evolution of the World Health Organization's programmatic actions to control diarrheal diseases

The Program for the Control of Diarrheal Diseases (CDD) of the World Health Organization (WHO) was created in 1978, the year the Health for All Strategy was launched at the Alma Ata International Conference on Primary Health Care. CDD quickly became one of the pillars of this strategy, with its primary goal of reducing diarrhea-associated mortality among infants and young children in developing countries. WHO expanded the previous cholera-focused unit into one that addressed all diarrheal diseases, and uniquely combined support to research and to national CDD Programs. We describe the history of the Program, summarize the results of the research it supported, and illustrate the outcome of the Program's control efforts at country and global levels. We then relate the subsequent evolution of the Program to an approach that was more technically broad and programmatically narrow and describe how this affected diarrheal diseases-related activities globally and in countries.

Short-term nutrition and growth indicators in 6-month- to 6-year-old children are improved following implementation of a multidisciplinary community-based programme in a chronic conflict setting

Objective:

We investigated short- and long-term indicators of malnutrition and diet before and after the community-based ‘Breaking the Cycle of Poverty’ multidisciplinary intervention.

Design:

A historically and geographically controlled study using data collected in 2013 and 2016. We compared the prevalence of short-term indicators (anaemia, breast-feeding duration and minimum dietary diversity) and long-term indicators (stunting and wasting) in exposed communities at two time points. We then compared these factors in geographic areas exposed or not exposed to intervention. We conducted logistic regression analyses on the 2016 sample to measure associations between living in intervention communities and child growth indicators.

Setting:

Berd region, a chronic conflict zone near the north-eastern border of Armenia and Azerbaijan.

Participants:

Children aged 6 months to 6 years.

Results:

Analyses included data from 2013 comprising 382 children, and data from 2016 comprising 348 children living in communities where the programme was implemented, and 635 children from unexposed communities. Anaemia prevalence in exposed communities was significantly lower in 2016 v. 2013 (10·9 v. 19·1 %, P < 0·01). Minimum dietary diversity (79·0 v. 68·1 %, P < 0·001) and breast-feeding duration (13·0 v. 11·5 months, P < 0·002) were significantly improved in exposed communities. Prevalences of stunting (11·5 v. 10·2 %, P = 0·57) and wasting (4·8 v. 2·0 %, P = 0·07) were not significantly different. Odds of anaemia were significantly lower (OR = 0·24, 95 % CI 0·16, 0·36) in intervention communities.

Conclusions:

Exposure to a community-based multidisciplinary intervention reduced the rate of anaemia and improved dietary indicators.

Drivers of Under-Five Stunting Trend in 14 Low- and Middle-Income Countries since the Turn of the Millennium: A Multilevel Pooled Analysis of 50 Demographic and Health Surveys

BACKGROUND

Understanding the drivers contributing to the decreasing trend in stunting is paramount to meeting the World Health Assembly's global target of 40% stunting reduction by 2025.

METHODS

We pooled data from 50 Demographic and Health Surveys since 2000 in 14 countries to examine the relationships between the stunting trend and potential factors at distal, intermediate, and proximal levels. A multilevel pooled trend analysis was used to estimate the association between the change in potential drivers at a country level and stunting probability for an individual child while adjusting for time trends and child-level covariates. A four-level mixed-effects linear probability regression model was fitted, accounting for the clustering of data by sampling clusters, survey-rounds, and countries.

RESULTS

Stunting followed a decreasing trend in all countries at an average annual rate of 1.04 percentage points. Among the distal factors assessed, a decrease in the Gini coefficient, an improvement in women's decision-making, and an increase in urbanization were significantly associated with a lower probability of stunting within a country. Improvements in households' access to improved sanitation facilities and drinking water sources, and children's access to basic vaccinations were the important intermediate service-related drivers, whereas improvements in early initiation of breastfeeding and a decrease in the prevalence of low birthweight were the important proximal drivers.

CONCLUSIONS

The results reinforce the need for a combination of nutrition-sensitive and -specific interventions to tackle the problem of stunting. The identified drivers help to guide global efforts to further accelerate stunting reduction and monitor progress against chronic childhood undernutrition.

Drivers of Under-Five Stunting Trend in 14 Low- and Middle-Income Countries since the Turn of the Millennium: A Multilevel Pooled Analysis of 50 Demographic and Health Surveys

BACKGROUND

Understanding the drivers contributing to the decreasing trend in stunting is paramount to meeting the World Health Assembly's global target of 40% stunting reduction by 2025.

METHODS

We pooled data from 50 Demographic and Health Surveys since 2000 in 14 countries to examine the relationships between the stunting trend and potential factors at distal, intermediate, and proximal levels. A multilevel pooled trend analysis was used to estimate the association between the change in potential drivers at a country level and stunting probability for an individual child while adjusting for time trends and child-level covariates. A four-level mixed-effects linear probability regression model was fitted, accounting for the clustering of data by sampling clusters, survey-rounds, and countries.

RESULTS

Stunting followed a decreasing trend in all countries at an average annual rate of 1.04 percentage points. Among the distal factors assessed, a decrease in the Gini coefficient, an improvement in women's decision-making, and an increase in urbanization were significantly associated with a lower probability of stunting within a country. Improvements in households' access to improved sanitation facilities and drinking water sources, and children's access to basic vaccinations were the important intermediate service-related drivers, whereas improvements in early initiation of breastfeeding and a decrease in the prevalence of low birthweight were the important proximal drivers.

CONCLUSIONS

The results reinforce the need for a combination of nutrition-sensitive and -specific interventions to tackle the problem of stunting. The identified drivers help to guide global efforts to further accelerate stunting reduction and monitor progress against chronic childhood undernutrition.

What explains the fall in child stunting in Sub-Saharan Africa?

There have been steep falls in rates of child stunting in much of Sub-Saharan Africa (SSA). Using Demographic and Health Survey data, we document significant reductions in stunting in seven SSA countries in the period 2005–2014. For each country, we distinguish potential determinants that move in a direction consistent with having contributed to the reduction in stunting from those that do not. We then decompose the change in stunting and in proximal determinants into a part that can be explained by changes in distal determinants and a residual part that captures the impact of unmeasured factors, such as vertical nutrition programs. We show that increases in coverage of child immunization, deworming medication and maternal iron supplementation often coincide with a fall in stunting. The magnitudes and directions of changes in two other proximal determinants -- age-appropriate feeding and diarrhea prevalence -- suggest that these have not been strong contributors to the fall in stunting. Utilization of maternity care emerges from the decomposition analysis as the most important distal determinant associated with reduced stunting, and also with increased coverage of iron supplementation, and, to a lesser extent, with child immunization and deworming medication. This circumstantial evidence is strong enough to warrant more detailed investigation of the extent to which maternity care is an effective channel through which to target further attacks on the blight of undernourished children.

•

The rate of children (<2 years old) who are stunted fell in many Sub-Saharan African countries in recent decades.

•

This reduction was associated with improved access to maternity care.

•

The improved access to maternity care may proxy for improvements in good quality preventive care.

•

The reduction in stunting was not associated with improved feeding practices or reduced incidence of diseases.

Child stunting is associated with child, maternal, and environmental factors in Vietnam

Child stunting in Vietnam has reduced substantially since the turn of the century but has remained relatively high for several years. We analysed data on children 6-59 months (n = 85,932) from the Vietnam Nutritional Surveillance System, a nationally representative cross-sectional survey. Multivariable Poisson regression models were used to estimate relative risk (RR) of stunting, stratified by child age and ecological region. Covariates at the child, maternal, household, and environmental levels were included based on available data and the World Health Organization conceptual framework on child stunting. Among children 6-23 months, the strongest associations with child stunting were child age in years (RR: 2.49; 95% CI [2.26, 2.73]), maternal height < 145 cm compared with ≥150 cm (RR: 2.04; 95% CI [1.85, 2.26]), living in the Northeast compared with the Southeast (RR: 2.01; 95% CI [1.69, 2.39]), no maternal education compared with a graduate education (RR: 1.77; 95% CI, [1.44, 2.16]), and birthweight < 2,500 g (RR: 1.75; 95% CI [1.55, 1.98]). For children 24-59 months, the strongest associations with child stunting were no maternal education compared with a graduate education (RR: 2.07; 95% CI [1.79, 2.40]), living in the Northeast compared with the Southeast (RR: 1.94; 95% CI [1.74, 2.16]), and maternal height < 145 cm compared with ≥150 cm (RR: 1.81; 95% CI [1.69, 1.94]). Targeted approaches that address the strongest stunting determinants among vulnerable populations are needed and discussed. Multifaceted approaches outside the health sector are also needed to reduce inequalities in socioeconomic status.

Differences in Tsimane children's growth outcomes and associated determinants as estimated by WHO standards vs. within-population references

Anthropometric measures are commonly converted to age stratified z-scores to examine variation in growth outcomes in mixed-age and sex samples. For many study populations, z-scores will differ if calculated from World Health Organization (WHO) growth standards or within-population references. The specific growth reference used may influence statistical estimates of growth outcomes and their determinants, with implications for biological inference. We examined factors associated with growth outcomes in a sample of 152 Tsimane children aged 0-36 months. The Tsimane are a subsistence-scale population in the Bolivian Amazon with high rates of infectious disease and growth faltering. To examine the influence of growth reference on statistical inferences, we constructed multiple plausible models from available infant, maternal, and household attributes. We then ran identical models for height-for-age (HAZ), weight-for-age (WAZ), and weight-for-height (WHZ), with z-scores alternately calculated from WHO and robust Tsimane Lambda-Mu-Sigma growth curves. The distribution of WHO relative to Tsimane HAZ scores was negatively skewed, reflecting age-related increases in lower HAZ. Standardized coefficients and significance levels generally agreed across WHO and Tsimane models, although the strength and significance of specific terms varied in some models. Age was strongly, negatively associated with HAZ and WAZ in nearly all WHO, but not Tsimane models, resulting in consistently higher R2 estimates. Age and weaning effects were confounded in WHO models. Biased estimates of determinants associated with WHO HAZ may be more extreme in small samples and for variables that are strongly age-patterned. Additional methodological considerations may be warranted when applying WHO standards to within-population studies, particularly for populations with growth patterns known to systematically deviate from those of the WHO reference sample.

Risk factors for stunting among children under five years: a cross-sectional population-based study in Rwanda using the 2015 Demographic and Health Survey

BACKGROUND

Child growth stunting remains a challenge in sub-Saharan Africa, where 34% of children under 5 years are stunted, and causing detrimental impact at individual and societal levels. Identifying risk factors to stunting is key to developing proper interventions. This study aimed at identifying risk factors of stunting in Rwanda.

METHODS

We used data from the Rwanda Demographic and Health Survey (DHS) 2014-2015. Association between children's characteristics and stunting was assessed using logistic regression analysis.

RESULTS

A total of 3594 under 5 years were included; where 51% of them were boys. The prevalence of stunting was 38% (95% CI: 35.92-39.52) for all children. In adjusted analysis, the following factors were significant: boys (OR 1.51; 95% CI 1.25-1.82), children ages 6-23 months (OR 4.91; 95% CI 3.16-7.62) and children ages 24-59 months (OR 6.34; 95% CI 4.07-9.89) compared to ages 0-6 months, low birth weight (OR 2.12; 95% CI 1.39-3.23), low maternal height (OR 3.27; 95% CI 1.89-5.64), primary education for mothers (OR 1.71; 95% CI 1.25-2.34), illiterate mothers (OR 2.00; 95% CI 1.37-2.92), history of not taking deworming medicine during pregnancy (OR 1.29; 95%CI 1.09-1.53), poorest households (OR 1.45; 95% CI 1.12-1.86; and OR 1.82; 95%CI 1.45-2.29 respectively).

CONCLUSION

Family-level factors are major drivers of children's growth stunting in Rwanda. Interventions to improve the nutrition of pregnant and lactating women so as to prevent low birth weight babies, reduce poverty, promote girls' education and intervene early in cases of malnutrition are needed.

Prevalence and Determinants of Stunting Among Preschool Children and Its Urban-Rural Disparities in Bangladesh

BACKGROUND

Despite improvements in the reduction of child stunting rates over the last decade, poor nutritional status still remains a public health concern in Bangladesh, where young children are the most vulnerable.

OBJECTIVE

The objective of this study is to capture the prevalence and determinants of childhood stunting and document its urban-rural disparities in the context of Bangladesh.

METHODS

The study used data from the Bangladesh Demographic and Health Survey of 2014. A bivariate analysis was performed to find out the differentials in prevalence of stunting, and multivariate logistic regression was performed to also assess the association of stunting with potential risk factors.

RESULTS

The overall prevalence of stunting was 36.3% and was significantly higher in rural (38.1%) areas than urban (31.2%) areas. In all 3 regression models, significantly higher odds were found among children aged 36 to 47 months compared to 6 to 12 months and among the children from the poorest households. In rural areas, male children were significantly more likely to be stunted (odds ratio = 1.31; 95% confidence interval: 1.12-1.53). Other significant risk factors for childhood stunting were maternal education and body mass index, children suffering from diarrhea, initial breast-feeding, and administrative divisions.

CONCLUSIONS

Disparities exist among urban and rural areas regarding stunting among the children younger than 5 in Bangladesh, which need to be reduced. Public health policies and interventions need to consider the risk factors in urban and rural areas separately.

Diet quality and risk of stunting among infants and young children in low- and middle-income countries

Age-appropriate complementary feeding practices are far from optimal among low- and middle-income countries with available data. The evidence on the association between feeding practices and linear growth is mixed. We sought to systematically examine the association between two indictors of dietary quality-dietary diversity and animal source food (ASF) consumption (WHO, 2008)-and stunting (length-for-age z-score) employing existing data from 39 Demographic and Health Surveys. Data on 74,548 children aged 6-23 months were pooled and multiple logistic regression models, adjusting for child, maternal, and household characteristics, employed to assess the association between dietary quality and stunting. Stratified models by child age and by World Bank country-income classifications (World Bank, 2015) were also applied. Children aged 6-23 months consuming zero food groups in the previous day had a 1.345 higher odds of being stunted when compared to the reference group (≥5 food groups); those who did not consume any ASF in the previous day had a 1.436 higher odds of being stunted compared to children consuming all three types of ASF (egg, meat, and dairy). We estimated that 2,629 cases of stunting would have been averted (12.6% of those stunted) among the population studied if all children had consumed five or more food groups. Outcomes by country-income groupings showed larger associations of diet diversity and ASF consumption for upper- and lower-middle income countries compared to low-income countries. In summary, dietary diversity and ASF consumption were associated with stunting, with associations varying by stratified groups.

Livestock ownership is associated with higher odds of anaemia among preschool-aged children, but not women of reproductive age in Ghana

Livestock ownership may influence anaemia through complex and possibly contradictory mechanisms. In this study, we aimed to determine the association of household livestock ownership with anaemia among women aged 15–49 years and children aged 6–59 months in Ghana and to examine the contribution of animal source foods (ASFs) to consumption patterns as a potential mechanism mediating this association. We analysed data on 4,441 women and 2,735 children from the 2014 Ghana Demographic and Health Survey and 16,772 households from the Ghana Living Standards Survey Round 6. Haemoglobin measurements were used to define anaemia (non‐pregnant women: <120 g/L; children: <110 g/L). Child‐ and household‐level ASF consumption data were collected from 24‐hour food group intake and food consumption and expenditure surveys, respectively. In multiple logistic regression models, household livestock ownership was associated with anaemia among children (OR, 95% CI: 1.5 [1.1, 2.0]), but not women (1.0 [0.83, 1.2]). Household ownership of chickens was associated with higher odds of anaemia among children (1.6 [1.2, 2.2]), but ownership of other animal species was not associated with anaemia among women or children. In path analyses, we observed no evidence of mediation of the association of household livestock ownership with child anaemia by ASF consumption. Ownership of livestock likely has limited importance for consumption of ASFs among young children in Ghana and may in fact place children at an increased risk of anaemia. Further research is needed to elucidate if and how pathogen exposure associated with livestock rearing may underlie this increased risk of anaemia.

Infant feeding and growth: putting the horse before the cart

Background

Previous observational studies have consistently shown slower weight and length gains in infants with prolonged breastfeeding than in those who were formula-fed from birth or breastfed for a shorter duration. These studies inferred that prolonged breastfeeding causes slower growth in infancy.

Objective

We compared infant growth associated with ≥12 mo of breastfeeding with a shorter duration of breastfeeding on the basis of 3 different analytic approaches to the same data from a randomized trial: intention-to-treat (ITT; "as randomized"), observational ("as fed"), and instrumental variable (IV; by using randomization as an "instrument" to achieve ≥12 mo of breastfeeding).

Design

This was a cluster-randomized trial of a breastfeeding-promotion intervention. Anthropometric measurements were obtained at birth and at 1, 2, 3, 6, 9, and 12 mo.

Results

The 3 analytic approaches yielded different results. The ITT approach showed more rapid growth in the first 2 mo among infants randomly assigned to the breastfeeding-promotion intervention than among control infants, with a decreasing difference over the ensuing months and nearly identical weight, length, and body mass index by 12 mo. The observational analysis showed a different trend: higher weight and length in infants who were breastfed ≥12 mo than in those who were breastfed <12 mo during the first 3 mo and no difference by 6 mo, while infants who were breastfed <12 mo showed increasingly higher weight and length from 6 to 12 mo. The IV analysis showed a temporal pattern that was similar to that seen in the ITT analysis, but with larger (and less precise) differences between infants breastfed for ≥12 compared with <12 mo.

Conclusions

We observed major differences in experimental (ITT and IV) compared with observational approaches to analyzing data obtained from the same children. These approaches lead to opposite causal inferences about the relation between infant feeding and growth and underline the importance of ensuring that the postulated cause (feeding) temporally precedes its hypothesized effect (growth). This trial is registered at http://www.isrctn.org/ as ISRCTN37687716.

Early feeding practices and stunting in Rwandan children: a cross-sectional study from the 2010 Rwanda demographic and health survey

Introduction

in Rwanda, despite different interventions to improve child nutrition status, malnutrition in children under five years of age continue to be a public health concern. This study aimed to evaluate the factors that contribute to childhood stunting by assessing feeding practices of Rwandans in children ≤ 2 years of age.

Methods

A cross-sectional study with data obtained from the 2010 Rwanda Demographic and Health Survey was conducted on 1,634 children ≤ 2 years of age with complete anthropometrical measurements. Multivariable logistic regression analysis was used to assess the association between feeding practices and childhood stunting.

Results

The results revealed that 35.1% of 1,634 children were stunted. Breastfeeding for 1 year (OR = 2.77, 95% CI = 1.91-4.01, P < 0.001) increased the risk of childhood stunting. After controlling for confounders, solid food initiation (OR = 1.21, 95% CI = 0.47-3.16, P≥ 0.690) and early initiation to breastfeeding (OR = 1.16, CI = 0.90-1.51, P = 0.243) were not associated with childhood stunting.

Conclusion

There was a significant association between continued breastfeeding for 1 year and childhood stunting. We suggest supplementary feeding for children who are breastfed for ≥1 year.

Individual, household, and community level risk factors of stunting in children younger than 5 years: Findings from a national surveillance system in Nepal

Despite substantial reductions in recent years in Nepal, stunting prevalence in children younger than 5 years remains high and represents a leading public health concern. To identify factors contributing to the stunting burden, we report multilevel risk factors associated with stunting in 4,853 children aged 6-59 months in a nationally and agroecologically representative random sample from the first year of the Policy and Science for Health, Agriculture, and Nutrition Community Studies, a community-based observational, mixed-panel study. Mixed effects logistic regressions controlling for multilevel clustering in the study design were used to examine the association of individual-, household-, and community-level factors associated with stunting. Stunting prevalence was 38% in our sample. After adjustment for potential confounding variables, maternal factors, including maternal height and education, were generally the strongest individual-level risk factors for stunting, adjusted odds ratio (AOR) = 2.52, 95% CI [1.96, 3.25], short (<145 cm) versus not short mothers; AOR = 2.09, 95% CI [1.48, 2.96], uneducated mothers versus secondary school graduates. Among the household- and community-level factors, household expenditure and community infrastructure (presence of paved roads, markets, or hospitals) were strongly, inversely associated with increased stunting risk, AOR = 1.68, 95% CI [1.27, 2.24], lowest versus highest household expenditure quintile; AOR = 2.38, 95% CI [1.36, 4.14], less developed (lacking paved roads, markets, or hospitals) versus more developed communities. Although most factors associated with stunting are not rapidly modifiable, areas for future research and possible interventions emerged.

What is significant about a single nursing session? An exploratory study

OBJECTIVES

Researchers and clinicians specializing in breastfeeding often rely on measuring one nursing session to characterize the breastfeeding relationship. However, less is known about the descriptive or statistically predictive characteristics of one nursing session. The purposes of this study are twofold: (1) to explore the relationships between variables in a single nursing session; and (2) to study the association between variables in a single nursing session and infant length-for-age (LAZ) and weight-for-age (WAZ).

METHODS

In 63 nursing mother-infant pairs in the United States, anthropometric measurement and observation of a single nursing session revealed six nursing session variables: fore milk fat percent, hind milk fat percent, infant milk intake, duration of session, time since last session, and time of day of session.

RESULTS

A principle factor analysis, undertaken to explore latent variables underlying the six session variables, revealed two factors: (1) loaded highly on fore and hind milk fat percentage, reflecting the overall fat percent in a feed; and (2) loaded highly on milk intake and hind milk fat percentage, indicating the process of breast emptying. In multivariate analyses of all session variables on infant LAZ and WAZ, only hind milk fat percentage was significantly negatively associated with LAZ (β = -0.14, P = .01 (two-tailed), R²  = 0.070), confirmed by a significant negative association between LAZ and factor one (β = -0.32, P = .05 (two-tailed), R²  = 0.090).

CONCLUSIONS

This research describes the dynamics of a single nursing session, and has the potential to help explain variation in infant growth and nutrition.

Cigarette smoking and the association with serous ovarian cancer in African American women: African American Cancer Epidemiology Study (AACES)

BACKGROUND

Smoking is a risk factor for mucinous ovarian cancer (OvCa) in Caucasians. Whether a similar association exists in African Americans (AA) is unknown.

METHODS

We conducted a population-based case-control study of incident OvCa in AA women across 11 geographic locations in the US. A structured telephone interview asked about smoking, demographic, health, and lifestyle factors. Odds ratios and 95% confidence intervals (OR, 95% CI) were estimated from 613 cases and 752 controls using unconditional logistic regression in multivariable adjusted models.

RESULTS

Associations were greater in magnitude for serous OvCa than for all OvCa combined. Compared to never smokers, increased risk for serous OvCa was observed for lifetime ever smokers (1.46, 1.11-1.92), former smokers who quit within 0-2 years of diagnosis (5.48, 3.04-9.86), and for total pack-years smoked among lifetime ever smokers (0-5 pack-years: 1.79, 1.23-2.59; >5-20 pack-years: 1.52, 1.05-2.18; >20 pack-years: 0.98, 0.61-1.56); however, we observed no dose-response relationship with increasing duration or consumption and no significant associations among current smokers. Smoking was not significantly associated with mucinous OvCa. Associations for all OvCa combined were consistently elevated among former smokers. The proportion of ever smokers who quit within 0-2 years was greater among cases (23%) than controls (7%).

CONCLUSIONS

Cigarette smoking may be associated with serous OvCa among AA, which differs from associations reported among Caucasians. Exposure misclassification or reverse causality may partially explain the absence of increased risk among current smokers and lack of dose-response associations. Better characterization of smoking patterns is needed in this understudied population.

Premastication and length for age among children under 24 months in Laos

Premastication of infant food by caregivers is common in Laos. Premastication is hypothesized to have both positive and negative implications for children, but the net effect of premastication on child health and nutrition is largely unknown because of a lack of research. This study quantitatively describes premastication in 5 provinces of Laos and examines the associations between premastication and the length of young children. We analyzed cross-sectional data from the Laos 2015 Food and Nutrition Security Survey to characterize premastication among children under 2 years of age (n = 1,661) and to test associations between premastication and child length-for-age z-score. We explored associations using multilevel mixed effects linear regression. Among children 0-23 months, 27.2% of mothers reported giving premasticated food in the past week. Receipt of premasticated food was inversely associated with length-for-age z-score after controlling for potential confounders (child's age, ethno-linguistic group, wealth, and parity) among children 6-13 months (β -0.36, CI [-0.68, -0.04]) and among children 14-23 months (β -0.43, CI [-0.81, -0.05]). For breastfed children 0-5 months who received complementary food, the coefficient was similar, but the association was not statistically significant (β -0.42, CI [-1.2, 0.37]). Premastication is a common feeding practice for children 0-23 months of age, and many infants consume premasticated food on a daily basis. There was a negative relationship between premastication and child length. However, given the cross-sectional nature of this study and potential unmeasured confounding factors, reverse causality or confounding cannot be ruled out. Longitudinal studies are needed to develop recommendations on premastication.

Feeding practices and growth among young children during two seasons in rural Ethiopia

Background

The use of indices of infant and young child feeding practices to predict growth has generated inconsistent results, possibly through age and seasonal confounding. The aim of this study was to evaluate the association of a dietary diversity score (DDS) and infant and child feeding index (ICFI) with growth among young children in a repeated cross-sectional and a follow-up study in two distinct seasons in rural southwest Ethiopia.

Methods

We used a repeated cross-sectional design comparing child feeding practices to nutritional status in 6–12 month old children during harvest (HS; n = 320) and pre-harvest season (PHS; n = 312). In addition, 6–12 month old children from the HS were reassessed 6 months later during PHS. In addition to child anthropometry, child feeding practices were collected using 24-h and 7-day dietary recalls.

Results

The mean (±SD) length-for-age z-score (LAZ) of the 6–12 month old children was −0.77 (±1.4) and −1.0 (±1.3) in HS and PHS, respectively, while the mean (±SD) of the follow-up children in PHS was −1.0 (±1.3). The median DDS (IQR) was 2.0 (1.0, 3.0.), 2.0 (2.0, 3.0) and 3.0 (2.0, 4.0) for the children in HS, PHS and the follow-up children in PHS, respectively. The DDS in HS was positively associated with LAZ at follow-up (β = 0.16; 95% CI: 0.01, 0.30; P = 0.03) after controlling for confounding factors. ICFI and DDS were not associated with mean LAZ, weight-for-height z-score and weight-for-age z-score within season. However, the odds of being stunted when having a DDS ≤ 2 was 2.3 times (95% CI: 1.10, 4.78; P = 0.03) higher compared to a DDS > 2 child in HS and 1.7 times (95% CI: 1.04, 2.71; P = 0.04) higher for the pooled sample of 6–12 months old children in HS and PHS.

Conclusions

The DDS was found to be an indicator for child stunting during the Ethiopian harvest season. The DDS can be an appropriate tool to evaluate the association of child feeding practices with child growth irrespective of season. Inclusion of other dimensions in the construction of ICFI should be considered in future analysis as we found no association with growth.

Electronic supplementary material

The online version of this article (doi:10.1186/s40795-017-0158-y) contains supplementary material, which is available to authorized users.

Timing of initiation, patterns of breastfeeding, and infant survival: prospective analysis of pooled data from three randomised trials

BACKGROUND

Although the benefits of exclusive breastfeeding for child health and survival, particularly in the post-neonatal period, are established, the independent beneficial effect of early breastfeeding initiation remains unclear. We studied the association between timing of breastfeeding initiation and post-enrolment neonatal and post-neonatal mortality up to 6 months of age, as well as the associations between breastfeeding pattern and mortality.

METHODS

We examined associations between timing of breastfeeding initiation, post-enrolment neonatal mortality (enrolment 28 days), and post-neonatal mortality up to 6 months of age (29-180 days) in a large cohort from three neonatal vitamin A trials in Ghana, India, and Tanzania. Newborn babies were eligible for these trials if their mother reported that they were likely to stay in the study area for the next 6 months, they could feed orally, were aged less than 3 days, and the primary caregiver gave informed consent. We excluded infants who initiated breastfeeding after 96 h, did not initiate, or had missing initiation status. We pooled the data from both randomised groups of the three trials and then categorised time of breastfeeding initiation as: at ≤1 h, 2-23 h, and 24-96 h. We defined breastfeeding patterns as exclusive, predominant, or partial breastfeeding at 4 days, 1 month, and 3 months of age. We estimated relative risks using log binomial regression and Poisson regression with robust variances. Multivariate models controlled for site and potential confounders.

FINDINGS

Of 99 938 enrolled infants, 99 632 babies initiated breastfeeding by 96 h of age and were included in our prospective cohort. 56 981 (57·2%) initiated breastfeeding at ≤1 h, 38 043 (38·2%) at 2-23 h, and 4608 (4·6%) at 24-96 h. Compared with infants initiating breastfeeding within the first hour of life, neonatal mortality between enrolment and 28 days was higher in infants initiating at 2-23 h (adjusted relative risk 1·41 [95% CI 1·24-1·62], p<0·0001), and in those initiating at 24-96 h (1·79 [1·39-2·30], p<0·0001). These associations were similar when deaths in the first 4 days of life were excluded (1·32 [1·10-1·58], p=0·003, for breastfeeding initiation at 2-23 h, and 1·90 [1·38-2·62], p=0·0001, for initiation at 24-96 h). When data were stratified by exclusive breastfeeding status at 4 days of age (p value for interaction=0·690), these associations were also similar in magnitude but with wider confidence intervals for initiation at 2-23 h (1·41 [1·12-1·77], p=0·003) and for initiation at 24-96 h (1·51 [0·63-3·65], p=0·357). Exclusive breastfeeding was also associated with the lower mortality during the first 6 months of life (1-3 months mortality: exclusive vs partial breastfeeding at 1 month 1·83 [1·45-2·32], p<0·0001, and exclusive breastfeeding vs no breastfeeding at 1 month 10·88 [8·27-14·31], p<0·0001).

INTERPRETATION

Our findings suggest that early initiation of breastfeeding reduces neonatal and early infant mortality both through increasing rates of exclusive breastfeeding and by additional mechanisms. Both practices should be promoted by public health programmes and should be used in models to estimate lives saved.

FUNDING

Bill & Melinda Gates Foundation through a grant to the WHO.

Effects of Health and Nutrition on Cognitive and Behavioural Development in Children in the First Three Years of Life: Part 1: Low Birthweight, Breastfeeding, and Protein-Energy Malnutrition

The following paper and its accompanying paper (Grantham-McGregor SM, et al. Effects of health and nutrition on cognitive and behavioural development in children in the first three years of life. Part 2: Infections and micronutrient deficiencies: iodine, iron, and zinc. Food Nutr Bull 1999;20:76–99) review the literature on the conditions that are prevalent and considered to be likely to affect child development and are therefore of public health importance. the reviews are selective, and we have generally focused on recent work, particularly in areas that remain controversial. the reviews are restricted to nutritional and health insults that are important in the first three years of life. Where possible, we have discussed the better studies. This paper considers the effects of low birthweight (focusing on small-for-gestational-age babies) and early childhood protein-energy malnutrition on mental, motor, and behavioural development. We have also included a section on breastfeeding because of its importance to child health and nutrition programmes.

How multiple episodes of exclusive breastfeeding impact estimates of exclusive breastfeeding duration: report from the eight-site MAL-ED birth cohort study

The duration of exclusive breastfeeding (EBF) is often defined as the time from birth to the first non‐breast milk food/liquid fed (EBFLONG), or it is estimated by calculating the proportion of women at a given infant age who EBF in the previous 24 h (EBFDHS). Others have measured the total days or personal prevalence of EBF (EBFPREV), recognizing that although non‐EBF days may occur, EBF can be re‐initiated for extended periods. We compared breastfeeding metrics in the MAL‐ED study; infants' breastfeeding trajectories were characterized from enrollment (median 7 days, IQR: 4, 12) to 180 days at eight sites. During twice‐weekly surveillance, caretakers were queried about infant feeding the prior day. Overall, 101 833 visits and 356 764 child days of data were collected from 1957 infants. Median duration of EBFLONG was 33 days (95% CI: 32–36), compared to 49 days based on the EBFDHS. Median EBFPREV was 66 days (95% CI: 62–70). Differences were because of the return to EBF after a non‐EBF period. The median number of returns to EBF was 2 (IQR: 1, 3). When mothers re‐initiated EBF (second episode), infants gained an additional 18.8 days (SD: 25.1) of EBF, and gained 13.7 days (SD: 18.1) (third episode). In settings where women report short gaps in EBF, programmes should work with women to return to EBF. Interventions could positively influence the duration of these additional periods of EBF and their quantification should be considered in impact evaluation studies. © 2016 John Wiley & Sons Ltd

Musculoskeletal Disorders and Perceived Work Demands among Female Nurses at a Tertiary Care Hospital in India

Introduction. Musculoskeletal disorders (MSD) are common among nurses and can affect patient outcomes. There is a dearth of literature on MSD among Indian nurses. The study objective was to measure prevalence of MSD and their association with perceived work demands and sociodemographic variables among female nurses at a tertiary care hospital in rural India. Methods. A cross-sectional study was undertaken in 2013 through interviewer administered questionnaires which comprised three parts: sociodemographic data, modified Nordic questionnaire, and perceived physical and psychological work demands. Results. 296 nurses with a mean age of 30.4 years participated. Prevalence of any MSD in the last seven days was 60.5% with low back pain being the most common and elbow pain the least common. Occurrence of any MSD was associated with age, number of children, working hours at home, BMI, and total work experience. High perceived physical demands score was associated with lower back (OR: 3.06) and knee pain (OR: 7.73). Conclusion. Prevalence of MSD was high and occurrence of lower back and knee MSD was associated with perceived physical demands. This information should be used as a benchmark and guiding tool for designing work place interventions to improve working conditions and health of nurses.

Infant and young child feeding practices and stunting in two highland provinces in Ecuador

The first two years of life are critical for growth and development. Little is known about infant and young child feeding (IYCF) practices in the Ecuadorian highlands and how they contribute to stunting. With the objective of understanding nutritional status and the influencing factors to design an intervention, we assessed the nutritional status of 293 infants and children between 0 and 24 months of age, living in 14 communities in the provinces of Tungurahua and Chimborazo using a cross-sectional study design. We used the WHO IYCF indicators to assess feeding practices; estimated dietary intake with 24-h recalls; and identified nutritious local foods by food frequency questionnaires. Multiple regression modelling was performed to identify correlates of nutritional status. Stunting was found in 56.2% of children. Mean protein, vitamin A and vitamin C intakes were above recommendations for all ages. Only infants 6.0 to 8.9 months of age and non-breastfed children 12-23.9 months of age consumed energy intakes below recommendations. Younger age groups had below recommended intakes for iron and calcium. While mean complementary food densities met recommendations for protein, vitamin A, vitamin C and energy, those for zinc, iron and calcium were lower than recommended. Older age, respiratory infections and being male were predictors of lower HAZ, whereas early initiation of breastfeeding, higher socioeconomic status, consumption of iron-rich foods and higher dietary protein density were protective. Interventions that promote and support optimal breastfeeding practices and enable increased consumption of nutritious local foods have potential to contribute to reducing stunting in this vulnerable population. © 2016 John Wiley & Sons Ltd.

Stunting, Underweight and Overweight in Children Aged 2.0-4.9 Years in Indonesia: Prevalence Trends and Associated Risk Factors

OBJECTIVE

The double burden of malnutrition affects many low and middle-income countries. This study aimed to: a) determine temporal trends in the prevalence of underweight, stunting, and at risk of overweight/ overweight or obesity in Indonesian children aged 2.0-4.9 years; and b) examine associated risk factors.

DESIGN

A repeated cross-sectional survey. This is a secondary data analysis of waves 1, 2, 3, and 4 (1993, 1997, 2000, and 2007) of the Indonesian Family Life Survey, which includes 13 out of 27 provinces in Indonesia. Height, weight and BMI were expressed as z-scores (2006 WHO Child Growth Standards). Weight-for-age-z-score <-2 was categorised as underweight, height-for-age-z-score <-2 as stunted, and BMI-z-score >+1, >+2, >+3 as at-risk, overweight and obese, respectively.

RESULTS

There are 938, 913, 939, and 1311 separate children in the 4 waves, respectively. The prevalence of stunting decreased significantly from waves 1 to 4 (from 50.8% to 36.7%), as did the prevalence of underweight (from 34.5% to 21.4%). The prevalence of 'at-risk'/overweight/obesity increased from 10.3% to 16.5% (all P<0.01). Stunting and underweight were related to lower birth weight, being breastfed for 6 months or more, having parents who were underweight or had short stature, and mothers who never attended formal education. Stunting was also higher in rural areas. Being at-risk, or overweight/obese were closely related to being in the youngest age group (2-2·9 years) or male, having parents who were overweight/obese or having fathers with university education.

CONCLUSIONS

The double burden of malnutrition occurs in Indonesian children. Development of policy to combine the management of chronic under-nutrition and over-nutrition is required.

Factors are not the same for risk of stopping exclusive breast-feeding and introducing different types of liquids and solids in HIV-affected communities in Ghana

Exclusive breast-feeding (EBF) for 6 months supports optimal infant growth, health and development. This paper examined whether maternal HIV status was associated with EBF and other infant feeding practices. Pregnant women were enrolled after HIV counselling, and their babies were followed up for up to 1 year. Data on household socio-economics and demographics, maternal characteristics and infants' daily diet were available for 482 infants and their mothers (150 HIV-positive (HIV-P), 170 HIV-negative (HIV-N) and 162 HIV-unknown (HIV-U)). Survival analyses estimated median EBF duration and time to introduction of liquids and foods; hazards ratios (HR) used data from 1-365 and 1-183 d, adjusting for covariates. Logistic regression estimated the probability of EBF for 6 months. Being HIV-P was associated with a shorter EBF duration (139 d) compared with HIV-N (163 d) and HIV-U (165 d) (P=0·004). Compared with HIV-N, being HIV-P was associated with about a 40 % higher risk of stopping EBF at any time point (HR 1·39; 95 % CI 1·06, 1·84; P=0·018) and less than half as likely to complete 6 months of EBF (adjusted OR 0·42; 95 % CI 0·22, 0·81; P=0·01). Being HIV-P tended to be or was associated with a higher risk of introducing non-milk liquids (HR 1·34; 95 % CI 0·98, 1·83; P=0·068), animal milks (HR 2·37; 95 % CI 1·32, 4·24; P=0·004) and solids (HR 1·56; 95 % CI 1·10, 2·22; P=0·011) during the first 6 months. Weight-for-age Z-score was associated with EBF and introducing formula. Different factors (ethnicity, food insecurity, HIV testing strategy) were associated with the various feeding behaviours, suggesting that diverse interventions are needed to promote optimal infant feeding.

Stunting coexisting with overweight in 2·0-4·9-year-old Indonesian children: prevalence, trends and associated risk factors from repeated cross-sectional surveys

Objective

The persistence of undernutrition, along with overweight and obesity, constitute the double burden of malnutrition. The present study aimed to: (i) describe the prevalence and trends of concurrent stunting and overweight in Indonesian children; (ii) identify potentially associated risk factors; and (iii) determine whether stunted children are at greater risk of overweight compared with those of healthy height.

Design

A secondary data analysis of children aged 2·0–4·9 years in four cross-sectional studies of the Indonesian Family Life Survey. Children’s height and BMI Z-scores were calculated based on the WHO Child Growth Standards (2006). We defined ‘concurrent stunting and overweight’ as height-for-age Z-score <−2 and BMI Z-score >+1. Multivariate generalised linear latent and mixed models were used to determine associated risk factors.

Setting

Thirteen out of twenty-seven provinces in Indonesia.

Subjects

Children (n 4101) from four waves of the Indonesian Family Life Survey (1993–2007).

Results

There were inconsistent trends in the prevalence of concurrent stunting and overweight from waves 1 to 4. Children were more likely to be stunted and overweight when they were in the youngest age group (2·0–2·9 years), were weaned after the age of 6 months, had short-statured mothers or lived in rural areas. Stunted children were significantly more likely to be overweight than healthy-height children (OR>1) but did not differ significantly different across each wave (OR=1·34–2·01).

Conclusions

Concurrent stunting and overweight occurs in Indonesian children aged 2·0–4·9 years. Current policies and programmes need to be tailored for the management of this phenomenon.

The lag-time approach improved drug-outcome association estimates in presence of protopathic bias

OBJECTIVES

Protopathic bias is a systematic error which occurs when measured exposure status may be affected by the latent onset of the target outcome. In this article, we aimed to discuss the benefits and drawbacks of the lag-time approach to address this type of bias.

STUDY DESIGN AND SETTING

The lag-time approach consists in excluding from exposure assessment the period immediately preceding the outcome detection date. With the help of simple causal diagrams, we illustrate the rationale and limitations of such strategy. The lag-time approach was illustrated in a case-crossover study, based on the health care utilization databases of the Italian Lombardy Region, on the real-world effectiveness of some respiratory drugs (exposure) in preventing asthma exacerbations (outcome).

RESULTS

A total of 7,300 of patients who were admitted to an emergency department (ED) for asthma during 2010-2012 (cases) were included. Use (vs. nonuse) of short-acting beta-agonists (SABAs, an asthma reliever medication) during the 90 days before the ED admission date was associated with an increased risk of the outcome [odds ratio (OR): 1.95; 95% confidence interval (CI): 1.72, 2.22]. This paradoxical finding may be explained by protopathic bias, as SABA use prior the ED admission may be affected by preceding respiratory distress. Indeed, when a 120-day period preceding the ED admission was ignored from drug exposure assessment (lag time), SABAs were found to be associated with a reduced risk of the outcome (OR: 0.81; 95% CI: 0.84, 0.92), as expected.

CONCLUSIONS

The lag-time approach can be a useful strategy to circumvent protopathic bias in observational studies.

Age of introduction of first complementary feeding for infants: a systematic review

Background

Despite a World Health Organization recommendation for exclusive breastfeeding of all full-term infants to 6 months of age, it is not clear what the health implications may be. Breast milk alone may not meet the nutrition needs for all growing infants, leaving them at risk for deficiencies. The objective of this study was to investigate the relationship between moderate (4 months) versus late (6 months) introduction of complementary foods to the full-term breastfed infant on iron status and growth.

Methods

An electronic search of peer-reviewed and gray-literature was conducted for randomized control trials (RCTs) and observational studies related to the timing of introduction of complementary foods. Iron status and growth data from the relevant RCTs were analyzed using RevMan 5.2.11.

Results

Three RCTs and one observational study met the inclusion criteria. Meta-analysis showed significantly higher hemoglobin levels in infants fed solids at 4 months versus those fed solids at 6 months in developing countries [mean difference [MD]: 5.0 g/L; 95 % CI: 1.5, 8.5 g/L; P = 0.005]. Meta-anaysis also showed higher serum ferritin levels in the 4-month group in both developed and developing countries [MD: 26.0 μg/L; 95 % CI: -0.1, 52.1 μg/L, P = 0.050], [MD: 18.9 μg/L; 95 % CI: 0.7, 37.1 μg/L, P = 0.040]. Short follow-up periods and small sample sizes of the included studies were the major limitations.

Conclusions

RCT evidence suggests the rate of iron deficiency anemia in breastfed infants could be positively altered by introduction of solids at 4 months.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0409-5) contains supplementary material, which is available to authorized users.

Exploring the risk-factor association between depression and incident stroke: a systematic review and meta-analysis

There is growing evidence that depression increases the risk of incident stroke. However, few studies have considered possible residual confounding effects by preexistent cerebrovascular and cardiac diseases. Therefore, we synthesized data from cohort studies to explore whether depressed individuals free of cerebrovascular and cardiac diseases are at higher risk of incident stroke. We searched the electronic databases PubMed and Medline for eligible cohort studies that examined the prospective association between depression and first-ever stroke. A random-effects model was used for quantitative data synthesis. Sensitivity analyses comprised cohort studies that considered a lag period with exclusion of incident strokes in the first years of follow-up to minimize residual confounding by preexistent silent strokes and excluded cardiac disease at baseline. Overall, we identified 28 cohort studies with 681,139 participants and 13,436 (1.97%) incident stroke cases. The pooled risk estimate revealed an increased risk of incident stroke for depression (relative risk 1.40, 95% confidence interval [CI] 1.27-1.53; P<0.0001). When we excluded incident strokes that occurred in the first years of follow-up, the prospective association between depression and incident stroke remained significant (relative risk 1.64, 95% CI 1.27-2.11; P<0.0001). This positive association also remained after we considered only studies with individuals with cardiac disease at baseline excluded (relative risk 1.43, 95% CI 1.19-1.72; P<0.0001). The prospective association of depression and increased risk of first-ever stroke demonstrated in this meta-analysis appears to be driven neither by preexistence of clinically apparent cerebrovascular and cardiovascular diseases nor by silent stroke.