The reliability of weight-for-length/height Z scores in children

Nutritional status of children with neurodevelopmental disorders: a cross-sectional study at a tertiary-level hospital in northern Bangladesh

BACKGROUND

Malnutrition in children with neurodevelopmental disorders (NDDs) is a significant global public health issue. Nutritional assessment combined with management or advice are essential to produce optimal outcomes.

OBJECTIVES

The objective of this study was to assess nutritional status and the sociodemographic profile of children with neurodevelopmental disorders in Bangladesh.

METHODS

A cross-sectional study was conducted from December to April 2020 among the population of children with NDDs who presented to the pediatric department of the TMSS Medical College and Rafatullah Community Hospital in Bogura during this period. Socio-demographic data along with anthropometric measurements of the children were taken. Assessment of nutritional status were made using metrics such as z-scores for weight-for-age (WAZ), height-for-age (HAZ), and body mass index-for-age (BAZ). Descriptive statistics (number and percentage) and analytical statistics (chi-square and logistic regression) were included.

RESULTS

58.6% of children displayed malnutrition, with 47.8% showing undernutrition (WHZ / BAZ - 1 SD-≤-3 SD), and 10.8% overnutrition (BAZ > 2SD). Significant negative associations were found between malnutrition and parental education level, urban residency, and monthly family income. Children diagnosed with cerebral palsy exhibited twice the likelihood to be malnourished (AOR 2.39, 95% CI 0.83-6.87). Furthermore, residing in rural regions was associated with an increased risk of experiencing malnutrition, as indicated by an adjusted odds ratio of 1.60 (95% CI 0.12-3.09).

CONCLUSIONS

While the results are cross-sectional, over half of children with NDDs were found to be malnourished, suggesting that children with NDD in Bangladesh are vulnerable to developing any form of malnutrition. Therefore, regular assessments and timely nutritional support may improve their situation.

Health Risk and Underweight

Anorexia nervosa is associated with a significant risk of morbidity and mortality. In clinical practice, health risk is assessed and estimated using routinely collected laboratory data. This study will develop a risk score using clinically relevant laboratory parameters. The related question is how to estimate the health risk associated with underweight using body weight, height and age.

METHODS

We used routinely collected laboratory parameters from a total of 4087 patients. The risk score was calculated on the basis of electrolytes, blood count, transaminases and LDH. The nine parameters used were summed as zlog-transformed values. Where appropriate, the scales were inverted so that high values represented higher risk. For statistical prediction of the risk score, weight/height and age reference values from the WHO, the CDC (Center of Disease Control) and representative studies of German children and adults (KIGGS and NNS) were used.

RESULTS

The score calculated from nine laboratory parameters already shows a convincing relationship with BMI. Among the weight measures used for height and age, the z-score from the CDC reference population emerged as the best estimate, explaining 34% of the variance in health risk measured by the laboratory score. The percentile rank for each age-specific median weight from the KIGGS/NNS still explained more than 31% of the variance. In contrast, percentiles explained less variance than BMI without age correction.

CONCLUSIONS

The score we used from routine laboratory parameters appears to be an appropriate measure for assessing the health risk associated with underweight, as measured by the quality of the association with BMI. For estimating health risk based on weight, height and age alone, z-scores and percentages of age-specific median weight, as opposed to percentiles, are appropriate parameters. However, the study also shows that existing age-specific BMI reference values do not represent risk optimally. Improved statistical estimation methods would be desirable.

Mid-upper arm circumference (MUAC) measurement usage among children with disabilities: A systematic review

Background: Anthropometric measurements, including mid-upper arm circumference (MUAC), are used for monitoring and evaluating children's nutritional status. Evidence is limited on optimal nutritional assessment for children with disabilities, who are at high risk for malnutrition. Aim: This study describes MUAC use among children with disabilities. Methods: Four databases (Embase, Global Health, Medline, and CINHAL) were searched from January 1990 through September 2021 using a predefined search strategy. Of the 305 publications screened, 32 papers were included. Data included children 6 months to 18 years old with disabilities. Data including general study characteristics, methods for MUAC measurement, terminology, and measurement references were extracted into Excel. Due to heterogeneity of the data, a narrative synthesis was used. Results: Studies from 24 countries indicate that MUAC is being used as part of nutritional assessment, but MUAC measurement methods, references, and cutoffs were inconsistent. Sixteen (50%) reported MUAC as a mean ± standard deviation (SD), 11 (34%) reported ranges or percentiles, 6 (19%) reported z-scores, and 4 (13%) used other methods. Fourteen (45%) studies included both MUAC and weight-for-height but nonstandard reporting limited comparability of the indicators for identifying those at risk of malnutrition. Conclusion: Although its speed, simplicity, and ease of use afford MUAC great potential for assessing children with disabilities, more research is needed to understand its appropriateness, and how it performs at identifying nutritionally high-risk children in comparison to other measures. Without validated inclusive measures to identify malnutrition and monitor growth and health, millions of children could have severe consequences for their development.

Prognostic value of different anthropometric indices over different measurement intervals to predict mortality in 6-59-month-old children

OBJECTIVE

To compare the prognostic value of mid-upper arm circumference (MUAC), weight-for-height Z-score (WHZ) and weight-for-age Z-score (WAZ) for predicting death over periods of 1, 3 and 6 months follow-up in children.

DESIGN

Pooled analysis of twelve prospective studies examining survival after anthropometric assessment. Sensitivity and false-positive ratios to predict death within 1, 3 and 6 months were compared for three individual anthropometric indices and their combinations.

SETTING

Community-based, prospective studies from twelve countries in Africa and Asia.

PARTICIPANTS

Children aged 6-59 months living in the study areas.

RESULTS

For all anthropometric indices, the receiver operating characteristic curves were higher for shorter than for longer durations of follow-up. Sensitivity was higher for death with 1-month follow-up compared with 6 months by 49 % (95 % CI (30, 69)) for MUAC < 115 mm (P < 0·001), 48 % (95 % CI (9·4, 87)) for WHZ < -3 (P < 0·01) and 28 % (95 % CI (7·6, 42)) for WAZ < -3 (P < 0·005). This was accompanied by an increase in false positives of only 3 % or less. For all durations of follow-up, WAZ < -3 identified more children who died and were not identified by WHZ < -3 or by MUAC < 115 mm, 120 mm or 125 mm, but the use of WAZ < -3 led to an increased false-positive ratio up to 16·4 % (95 % CI (12·0, 20·9)) compared with 3·5 % (95 % CI (0·4, 6·5)) for MUAC < 115 mm alone.

CONCLUSIONS

Frequent anthropometric measurements significantly improve the identification of malnourished children with a high risk of death without markedly increasing false positives. Combining two indices increases sensitivity but also increases false positives among children meeting case definitions.

Anthropometric criteria for best-identifying children at high risk of mortality: a pooled analysis of twelve cohorts

OBJECTIVE

To understand which anthropometric diagnostic criteria best discriminate higher from lower risk of death in children and explore programme implications.

DESIGN

A multiple cohort individual data meta-analysis of mortality risk (within 6 months of measurement) by anthropometric case definitions. Sensitivity, specificity, informedness and inclusivity in predicting mortality, face validity and compatibility with current standards and practice were assessed and operational consequences were modelled.

SETTING

Community-based cohort studies in twelve low-income countries between 1977 and 2013 in settings where treatment of wasting was not widespread.

PARTICIPANTS

Children aged 6 to 59 months.

RESULTS

Of the twelve anthropometric case definitions examined, four (weight-for-age Z-score (WAZ) <-2), (mid-upper arm circumference (MUAC) <125 mm), (MUAC < 115 mm or WAZ < -3) and (WAZ < -3) had the highest informedness in predicting mortality. A combined case definition (MUAC < 115 mm or WAZ < -3) was better at predicting deaths associated with weight-for-height Z-score <-3 and concurrent wasting and stunting (WaSt) than the single WAZ < -3 case definition. After the assessment of all criteria, the combined case definition performed best. The simulated workload for programmes admitting based on MUAC < 115 mm or WAZ < -3, when adjusted with a proxy for required intensity and/or duration of treatment, was 1·87 times larger than programmes admitting on MUAC < 115 mm alone.

CONCLUSIONS

A combined case definition detects nearly all deaths associated with severe anthropometric deficits suggesting that therapeutic feeding programmes may achieve higher impact (prevent mortality and improve coverage) by using it. There remain operational questions to examine further before wide-scale adoption can be recommended.

Evaluating the role of breastfeeding peer supporters' intervention on the inpatient management of malnourished infants under 6 months in Kenyan public hospitals

BACKGROUND

The 2013 WHO guidelines for nutritional rehabilitation of malnourished infants under six months (u6m) focus on inpatient re-establishment of exclusive breastfeeding and recommends discharge when infant is gaining weight on breastmilk alone. Guided by a breastfeeding support tool, breastfeeding peer supporters (BFPS) can support implementation of these guideline by providing continuous individualised breastfeeding counselling to mothers of malnourished infants u6m. Recording and sharing information plays an important role in shaping in-patient care but little is known about recording practices for inpatient nutrition rehabilitation of infants u6m or how such practices affect care. We set out to explore introduction of BFPS into hospitals, and how it shaped the recording and practices of care for acutely malnourished infants u6m.

METHODS

We applied a descriptive, exploratory design involving a pre and during intervention audit of the infant u6m inpatient records in two hospitals in Kenya, as well as pre- and post-intervention in-depth interviews with health workers involved in the care of admitted infants u6m. We developed an audit tool and used it to extract routine data on patient information from hospital records. Data were entered into a REDCap database and analyzed using STATA 17.0 software. We conducted thirty in-depth interviews with health workers exploring their care practices and their perceived effect of the presence of the BFPS on health workers treatment practices. We analysed interview data using thematic framework approach.

RESULTS

A total of 170 and 65 inpatient files were available for the audit during the pre- and post-intervention period respectively. The presence of the BFPS seemed to have encouraged the recording of (i) breastfeeding status upon admission, (ii) breastfeeding management plan and (iii) reporting of its implementation and progress during treatment. The breastfeeding peer support intervention had a positive impact on breastfeeding recording and reporting practices. Health workers reported that the BFPS facilitated the recording of observed breastfeeding data and how their records influenced final inputs of breastfeeding support provided in the inpatient file.

CONCLUSIONS

Guideline implementation tools facilitate effective application of guidelines and should accompany any guideline formulation process and have their effectiveness at recording and monitoring progress evaluated.

Prevalence and socioeconomic determinants of the double burden of malnutrition in mother-child pairs in Latin America and the Caribbean

Background

The double burden of malnutrition (DBM), which refers to the coexistence of overnutrition and undernutrition among populations, households or individuals, is a growing problem in low/middle-income countries. The Latin America and the Caribbean (LAC) region has been particularly affected by the DBM, following a nutrition transition and a rapid increase in overweight, obesity and diet-related disease, while high levels of undernutrition persist. This study aims to describe the prevalence of four different DBM definitions in mother-child pairs across nine LAC countries and investigate the socioeconomic determinants of overweight mothers with at least one stunted child (SCOM).

Methods

We used cross-sectional data from the Demographic and Health Surveys for all analyses. We used descriptive statistics to obtain prevalence rates and conducted multiple logistic regression analyses to investigate the association between SCOM households and socioeconomic determinants, including wealth index, maternal education, place of residency and whether the mother was working, adjusted for a range of variables.

Results

Overweight/obese mothers with at least one anaemic child were the most common type of DBM, with a prevalence of 19.39%, followed by SCOM with a prevalence of 10.44%. Statistically significant socioeconomic predictors of SCOM were households with a lower wealth index, lower maternal education and living in rural areas.

Conclusion

This study showed that the overall prevalence of most DBM definitions examined was high, which points to the need for urgent interventions in the LAC region. The unique set of socioeconomic predictors of SCOM identified in this study calls for future double-duty policies that simultaneously target food affordability, nutrition education and access to healthy food.

Anthropometric Indicators as Predictors of Mortality in Early Life Among Low Birthweight Indian Infants

Background

Low birthweight (LBW) babies (<2.5 kg) are at higher risk of mortality and weight for height z score is currently recommended for identifying infants at risk of mortality.

Objective

To compare different anthropometric measures at 28-day of age in a cohort of LBW Indian infants for predicting mortality between 28-day and 180-day of age.

Methods

We used data from an individually randomized controlled trial of LBW infants weighing between 1,500 and 2,250 g. Sensitivity, specificity, positive, and negative likelihood ratios, positive and negative predictive values, and area under receiver operating characteristics curves (AUC) were used to estimate the discrimination of mortality risk. The Cox regression was used to estimate hazard ratios and population attributable fraction for each anthropometric indicator. These estimates were calculated for individual as well as combinations of anthropometric indicators at the cut-off of –2 and –3 SD of the WHO 2006 growth standards.

Results

Severe underweight (weight-for-age z-scores [WAZ] < –3) had a sensitivity of 75.0%, specificity of 68.0% with an AUC of 0.72. The risk of death was higher (HR 6.18; 95% CI 4.29–8.90) with a population attributable fraction of 0.63 (95% CI 0.52–0.72) for infants severely underweight at 28-day of age. Combination of different anthropometric measures did not perform better than individual measures.

Conclusion

Severe underweight (WAZ < –3) better discriminated deaths among LBW infants < 6 months of age. It can be considered for diagnosis of nutritionally at-risk infants in this age group.

Clinical Trial Registration

[ClinicalTrials.gov], identifier [NCT02653534].

Assessing the role of mid upper arm circumference in identification of low birthweight and wasting in early infancy in India

AIM

We conducted this study to examine the mid upper-arm circumference (MUAC) of full-term infants from birth to 6 months; construct gender-specific MUAC graphs; and assess the role of MUAC as a surrogate marker for low birthweight and wasting in infants younger than 6 months.

METHODS

This is a prospective longitudinal study of 268 (133 female and 135 male) new-borns in a tertiary care centre in Navi Mumbai, India. We measured weight, length, head circumference and MUAC. We drew the MUAC curves for the first 6 months using the mean MUAC and standard deviation (SD) values and assessed the diagnostic test properties of MUAC at birth as a marker of low birthweight.

RESULTS

The mean (SD) birthweight of the male and female new-borns was 2756.2 g (368.1) and 2803.8 g (326.2), respectively (P = 0.25). The mean (SD) MUAC at birth was 8.7 (0.3) cm in males and 8.8 (0.2) cm in females, respectively (P = 0.14). The plotted mean MUAC curve in infants who were classified with wasting was between the -1SD and -2SD in both genders. The sensitivity and NPV for detecting low birthweight were 100% at cut-off of 8.6 cm in females and 8.7 cm in males, respectively (area under the curve: 0.92 (females) and 0.96 (males)).

CONCLUSION

MUAC may be a good proxy for low birthweight at birth and the curves from our study show that it may also help in the diagnosis of wasting in infants below 6 months of age in the community, particularly in resource-constrained settings.

Growth monitoring and mortality risk in low birthweight infants: a birth cohort study in Burkina Faso

Background: Wasting and underweight in infancy is an increasingly recognised problem but consensus on optimum assessment is lacking. In particular, there is uncertainty on how to interpret anthropometry among low birth weight (LBW) infants who may be growing normally. This research aimed to determine growth of infants from birth to two months (around age of vaccination) and the mortality risk of underweight LBW infants compared to normal birth weight (NBW) infants at two and six months age. Methods: A secondary analysis of a birth cohort of 1103 infants in Burkina Faso was conducted. Anthropometry was performed monthly from 0 to 12 months. We assessed associations with mortality using Cox proportional hazards models and assessed discriminatory values using area under receiver operating characteristics curves. Results: Eighty-six (7.8%) children died by age one year, 26/86 (30%) and 51/86 (59%) within two and six months, respectively. At age two months, weight gain since birth did not better discriminate mortality risk than current weight-for-age (P=0.72) or mid-upper arm circumference (P=0.21). In total, 227 (21%) LBW infants had increased risk of mortality: adjusted hazards ratio (aHR) 3.30 (95%CI 2.09 to 4.90). Among infants who were underweight at two and six months, LBW infants (64% and 49%, respectively) were not at reduced risk of death compared to NBW infants (aHR 2.63 (95%CI 0.76 to 9.15) and 2.43 (95%CI 0.74 to 7.98), respectively). Conclusion: Assessing weight gain since birth does not offer advantages over immediate anthropometry for discriminating mortality risk. LBW infants who are later identified as underweight require care to help prevent mortality.

Malnutrition in Infants Aged under 6 Months Attending Community Health Centres: A Cross Sectional Survey

A poor understanding of malnutrition burden is a common reason for not prioritizing the care of small and nutritionally at-risk infants aged under-six months (infants u6m). We aimed to estimate the anthropometric deficit prevalence in infants u6m attending health centres, using the Composite Index of Anthropometric Failure (CIAF), and to assess the overlap of different individual indicators. We undertook a two-week survey of all infants u6m visiting 18 health centres in two zones of the Oromia region, Ethiopia. We measured weight, length, and MUAC (mid-upper arm circumference) and calculated weight-for-length (WLZ), length-for-age (LAZ), and weight-for-age z-scores (WAZ). Overall, 21.7% (95% CI: 19.2; 24.3) of infants u6m presented CIAF, and of these, 10.7% (95% CI: 8.93; 12.7) had multiple anthropometric deficits. Low MUAC overlapped with 47.5% (95% CI: 38.0; 57.3), 43.8% (95% CI: 34.9; 53.1), and 42.6% (95% CI: 36.3; 49.2) of the stunted, wasted, and CIAF prevalence, respectively. Underweight overlapped with 63.4% (95% CI: 53.6; 72.2), 52.7% (95% CI: 43.4; 61.7), and 59.6% (95% CI: 53.1; 65.9) of the stunted, wasted, and CIAF prevalence, respectively. Anthropometric deficits, single and multiple, are prevalent in infants attending health centres. WAZ overlaps more with other forms of anthropometric deficits than MUAC.

Growth monitoring and mortality risk in low birthweight infants: a birth cohort study in Burkina Faso

Background: Wasting and underweight in infancy is an increasingly recognised problem but consensus on optimum assessment is lacking.  In particular, there is uncertainty on how to interpret anthropometry among low birth weight (LBW) infants who may be growing normally. This research aimed to determine growth of infants from birth to two months (around age of vaccination) and the mortality risk of underweight LBW infants compared to normal birth weight (NBW) infants at two and six months age. Methods: A secondary analysis of a birth cohort of 1103 infants in Burkina Faso was conducted. Anthropometry was performed monthly from 0 to 12 months. We assessed associations with mortality using Cox proportional hazards models and assessed discriminatory values using area under receiver operating characteristics curves. Results: Eighty-six (7.8%) children died by age one year, 26/86 (30%) and 51/86 (59%) within two and six months, respectively. At age two months, weight gain since birth did not better discriminate mortality risk than current weight-for-age (P=0.72) or mid-upper arm circumference (P=0.21). In total, 227 (21%) LBW infants had increased risk of mortality: adjusted hazards ratio (aHR) 3.30 (95%CI 2.09 to 4.90).  Among infants who were underweight at two and six months, LBW infants (64% and 49%, respectively) were not at reduced risk of death compared to NBW infants (aHR 2.63 (95%CI 0.76 to 9.15) and 2.43 (95%CI 0.74 to 7.98), respectively). Conclusion: Assessing weight gain since birth does not offer advantages over immediate anthropometry for discriminating mortality risk. LBW infants who are later identified as underweight require care to help prevent mortality.

Diagnostic measures for severe acute malnutrition in Indian infants under 6 months of age: a secondary data analysis

Background

Weight for length z-score (WLZ) < − 3 is currently used to define severe acute malnutrition (SAM) among infants. However, this approach has important limitations for infants younger than 6 months of age as WLZ cannot be calculated using WHO growth standards if infant length is < 45 cm. Moreover, length for age z-score (LAZ) and weight for length z-score (WLZ) are least reliable measures, with high chances of variation, and less chances of detecting undernutrition in under 6 months infants. The objective of the current analysis was to compare WLZ with WAZ and LAZ in a cohort of Indian infants in predicting the deaths between 6 weeks and 6 months of age.

Methods

The data was from an individually randomized trial conducted in slums of Delhi, India in which infants’ weight and length were measured at 6 weeks of age (at the time of the first immunization visit). Vital status of the infants was documented from 6 weeks to 6 months of age. The sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios were calculated for WAZ < -3, WLZ < -3, and LAZ < -3 for deaths between 6 weeks and 6 months of age. The receiver operating characteristics curve was calculated for each of the above anthropometric indicators.

Results

For deaths occurring between 6 weeks to 6 months of age, the specificity ranged between 85.9–95.9% for all three anthropometric indicators. However, the sensitivity was considerably higher for WAZ; it was 64.6% for WAZ < -3, 39.1% for LAZ < -3, and 25.0% for WLZ < -3. WAZ < -3 had higher area under curve (0.75; 95% CI: 0.68, 0.82) and hence, better discriminated deaths between 6 weeks and 6 months of age than WLZ < -3. The adjusted relative risk (RR 10.6, 95% CI 5.9, 18.9) and the population attributable fraction (PAF 57.9, 95% CI 38.8, 71.0%) of mortality was highest for WAZ < -3.

Conclusions

We found WAZ < -3 at 6 weeks of age to be a better predictor of death in the 6 weeks to 6 months of life in comparison to WLZ < -3 and LAZ < -3 and propose that it should be considered to diagnose SAM in this age group.

The Effect of Nutritional Support on the Disease Progression and Survival in Pediatric Patients with Solid Tumors

Cancer is one of the leading causes of death for children; however, appropriate nutritional status can positively affect survival. The aim of this study was to determine to what extent malnutrition risk screening and intensified nutrition support, provided by a professional team, promoted disease progression and survival in pediatric patients with solid tumors. 145 pediatric cancer patients (average age 6.3 ± 5.6 and 6.7 ± 5.4 years) with solid tumors undergoing chemotherapy participated in the study. Two 3-year periods were studied: 2009-2011 and 2012-2014. Patient characteristics and treatment protocols were identical, but in Period 2, with the foundation of our nutrition support team malnutrition risk screening was made mandatory upon every hospital admission. As a result of intensified nutrition support the time from diagnosis to completion of treatment (802 vs. 512 day, p < 0.001) and the need for antimycotic treatment reduced significantly (47.8% vs. 29.1%, p = 0.036). The total percentage of surviving children was 60.3% and 75.0% in Period 1 and 2 respectively. Decrease in weight-for-height percentile during treatment and central nervous system tumors are significant predictors of a less favorable survival. Malnutrition risk screening and intensified nutrition therapy have positive effects on nutritional status and therefore patient survival in pediatric cancer patients.

Introducing a drift and diffusion framework for childhood growth research

Background: Growth trajectories are highly variable between children, making epidemiological analyses challenging both to the identification of malnutrition interventions at the population level and also risk assessment at individual level. We introduce stochastic differential equation (SDE) models into child growth research. SDEs describe flexible dynamic processes comprising: drift - gradual smooth changes - such as physiology or gut microbiome, and diffusion - sudden perturbations, such as illness or infection. Methods: We present a case study applying SDE models to child growth trajectory data from the Haydom, Tanzania and Venda, South Africa sites within the MAL-ED cohort. These data comprise n=460 children aged 0-24 months. A comparison with classical curve fitting (linear mixed models) is also presented. Results: The SDE models offered a wide range of new flexible shapes and parameterizations compared to classical additive models, with performance as good or better than standard approaches. The predictions from the SDE models suggest distinct longitudinal clusters that form distinct 'streams' hidden by the large between-child variability. Conclusions: Using SDE models to predict future growth trajectories revealed new insights in the observed data, where trajectories appear to cluster together in bands, which may have a future risk assessment application. SDEs offer an attractive approach for child growth modelling and potentially offer new insights.

Socioeconomic inequalities in food insecurity and malnutrition among under-five children: within and between-group inequalities in Zimbabwe

Background

Food insecurity and malnutrition in children are pervasive public health concerns in Zimbabwe. Previous studies only identified determinants of food insecurity and malnutrition with very little efforts done in assessing related inequalities and decomposing the inequalities across household characteristics in Zimbabwe. This study explored socioeconomic inequalities trend in child health using regression decomposition approach to compare within and between group inequalities.

Methods

The study used Demographic Health Survey (DHS) data sets of 2010\11 and 2015. Food insecurity in under-five children was determined based on the WHO dietary diversity score. Minimum dietary diversity was defined by a cut- off point of > 4 therefore, children with at least 3 of the 13 food groups were defined as food insecure. Malnutrition was assessed using weight for age (both acute and chronic under-nutrition) Z-scores. Children whose weight-for-age Z-score below minus two standard deviations (− 2 SD) from the median were considered malnourished. Concentration curves and indices were computed to understand if malnutrition was dominant among the poor or rich. The study used the Theil index and decomposed the index by population subgroups (place of residence and socioeconomic status).

Results

Over the study period, malnutrition prevalence increased by 1.03 percentage points, while food insecurity prevalence decreased by 4.35 percentage points. Prevalence of malnutrition and food insecurity increased among poor rural children. Theil indices for nutrition status showed socioeconomic inequality gaps to have widened, while food security status socioeconomic inequality gaps contracted for the period under review.

Conclusion

The study concluded that unequal distribution of household wealth and residence status play critical roles in driving socioeconomic inequalities in child food insecurity and malnutrition. Therefore, child food insecurity and malnutrition are greatly influenced by where a child lives (rural/urban) and parental wealth.

Introducing a drift and diffusion framework for childhood growth research

Background: Growth trajectories are highly variable between children, making epidemiological analyses challenging both to the identification of malnutrition interventions at the population level and also risk assessment at individual level. We introduce stochastic differential equation (SDE) models into child growth research. SDEs describe flexible dynamic processes comprising: drift - gradual smooth changes - such as physiology or gut microbiome, and diffusion - sudden perturbations, such as illness or infection. Methods: We present a case study applying SDE models to child growth trajectory data from the Haydom, Tanzania and Venda, South Africa sites within the MAL-ED cohort. These data comprise n=460 children aged 0-24 months. A comparison with classical curve fitting (linear mixed models) is also presented. Results: The SDE models offered a wide range of new flexible shapes and parameterizations compared to classical additive models, with performance as good or better than standard approaches. The predictions from the SDE models suggest distinct longitudinal clusters that form distinct 'streams' hidden by the large between-child variability. Conclusions: Using SDE models to predict future growth trajectories revealed new insights in the observed data, where trajectories appear to cluster together in bands, which may have a future risk assessment application. SDEs offer an attractive approach for child growth modelling and potentially offer new insights.

Performance of mid-upper arm circumference to diagnose acute malnutrition in a cross-sectional community-based sample of children aged 6-24 months in Niger

BACKGROUND/OBJECTIVES

Accurate, early identification of acutely malnourished children has the potential to reduce related child morbidity and mortality. The current World Health Organisation (WHO) guidelines classify non-oedematous acute malnutrition among children under five using Mid-Upper Arm Circumference (MUAC) or Weight-for-Height Z-score (WHZ). However, there is ongoing debate regarding the use of current MUAC cut-offs. This study investigates the diagnostic performance of MUAC to identify children aged 6–24 months with global (GAM) or severe acute malnutrition (SAM).

SUBJECTS/METHODS

Cross-sectional, secondary data from a community sample of children aged 6-24 months in Niger were used for this study. Children with complete weight, height and MUAC data and without clinical oedema were included. Using WHO guidelines for GAM (WHZ < −2, MUAC < 12.5 cm) and SAM (WHZ < −3, MUAC < 11.5 cm), the sensitivity (Se), specificity (Sp), predictive values, Youden Index and Receiver Operating Characteristic (ROC) curves were calculated for MUAC when compared with the WHZ reference criterion.

RESULTS

Of 1161 children, 23.3% were diagnosed with GAM using WHZ, and 4.4% with SAM. Using current WHO cut-offs, the Se of MUAC to identify GAM was greater than for SAM (79 vs. 57%), yet the Sp was lower (84 vs. 97%). From inspection of the ROC curve and Youden Index, Se and Sp were maximised for MUAC < 12.5 cm to identify GAM (Se 79%, Sp 84%), and MUAC < 12.0 cm to identify SAM (Se 88%, Sp 81%).

CONCLUSIONS

The current MUAC cut-off to identify GAM should continue to be used, but when screening for SAM, a higher cut-off could improve case identification. Community screening for SAM could use MUAC < 12.0 cm followed by appropriate treatment based on either MUAC < 11.5 cm or WHZ < −3, as in current practice. While the practicalities of implementation must be considered, the higher SAM MUAC cut-off would maximise early case-finding of high-risk acutely malnourished children.

Anthropometry at birth and at age of routine vaccination to predict mortality in the first year of life: A birth cohort study in BukinaFaso

BACKGROUND

The World Health Organization currently defines severe acute malnutrition (SAM) in infants aged under 6 months of age using weight-for-length Z score (WLZ). Given widespread use of mid-upper arm circumference (MUAC) for identifying SAM in older children and weight-for-age (WAZ) for growth monitoring, there is increasing debate about the optimal anthropometric criteria to best identify infants u6m at-risk of mortality.

OBJECTIVE

To determine the discriminatory value for mortality during the first 12 months of life of anthropometry taken at birth and at age two months (approximate age of routine vaccination).

DESIGN

Data were analyzed from a birth cohort recruited between April and December of 2004 at four health facilities within Bansalogho District in Burkina Faso. Infants were followed up for 12 months. Mortality risks were estimated using hazards ratios (HR). Discriminatory value was assessed using receiver operating characteristic curves.

RESULTS

Of 1,103 infants, 227 (21%) were low birthweight (LBW). During 12 months, 86 (7.8%) infants died; 38 (44%) among the LBW group. At birth, MUAC<9.0cm, weight<2.5kg, length<44.2cm and incalculable WLZ were associated with mortality. Sixty (70%) deaths occurred after the age of two months; 26 (43%) among LBW infants. At age two months, any MUAC <11.5cm, weight <3.8kg (WAZ<-3) and length <52.4cm (LAZ<-3) were associated with risk of mortality. WLZ was not associated with mortality at any threshold. Birth weight did not modify the effect of the association between month two MUAC and one-year mortality (P = 0.33).

CONCLUSION

Infants at heightened risk of mortality and are better identified during early infancy by MUAC or WFA than by WLZ. LBW infants with low anthropometry at the age of routine immunizations remain at elevated risk than normal birth weight (NBW)infants and require intervention. Effectiveness, cost-effectiveness and coverage of applying proposed thresholds should be investigated as a priority to inform policy and practice.

Relationship between socioeconomic status and weight gain during infancy: The BeeBOFT study

BACKGROUND

Increased weight gain during infancy is a risk factor for obesity and related diseases in later life. The aim of the present study was to investigate the association between socioeconomic status (SES) and weight gain during infancy, and to identify the factors mediating the association between SES and infant weight gain.

METHODS

Subjects were 2513 parent-child dyads participating in a cluster randomized controlled intervention study. Family SES was indexed by maternal education level. Weight gain in different time windows (infant age 0-3, 0-6, and 6-12 months) was calculated by subtracting the weight for age z-score (WAZ) between the two time-points. Path analysis was performed to examine the mediating pathways linking SES and infant weight gain.

RESULTS

On average, infants of low-educated mothers had a lower birth weight and caught-up at approximately 6 months. In the period of 0-6 months, infants with low-educated mothers had an 0.42 (95% CI 0.27-0.57) higher gain in weight for age z-score compared to children with high-educated mothers. The association between maternal education level and increased infant weight gain in the period of 0-6 months can be explained by infant birth weight, gestational age at child birth, duration of breastfeeding, and age at introduction of complementary foods. After adjusting all the mediating factors, there was no association between maternal education level and infant weight gain.

CONCLUSION

Infants with lower SES had an increased weight gain during the first 6 months of infancy, and the effect can be explained by infant birth weight, gestational age at child birth, and infant feeding practices.

Effect of Zinc Supplementation on Growth Outcomes in Children under 5 Years of Age

(1) Background: The effects of zinc supplementation on child growth, and prior reviews of these studies, have shown mixed results. We aim to systematically review and meta-analyze randomized controlled trials evaluating effects of preventive zinc supplementation for 3 months or longer during pregnancy or in children up to age 5 years on pregnancy outcomes and child growth; (2) Methods: We searched PubMed, EMBASE, Cochrane Library, Web of Science, and trial registries for eligible trials up to October 10, 2017. Inclusion selection and data extractions were performed independently and in duplicate. Study quality was evaluated by the Cochrane Risk of Bias tool. Findings were pooled using random effects meta-analysis, with heterogeneity assessed by I² and τ² statistic, stratified analyses, and meta-regression, and publication bias by Egger's and Begg's tests; (3) Results: Seventy-eight trials with 34,352 unique participants were identified, including 24 during pregnancy and 54 in infancy/childhood. Maternal zinc supplementation did not significantly increase birth weight (weighted mean difference (WMD) = 0.08 kg, 95%CI: -0.05, 0.22) or decrease the risk of low birth weight (RR = 0.76, 95%CI: 0.52-1.11). Zinc supplementation after birth increased height (WMD = 0.23 cm, 95%CI: 0.09-0.38), weight (WMD = 0.14 kg, 95%CI: 0.07-0.21), and weight-for-age Z-score (WMD = 0.04, 95%CI: 0.001-0.087), but not height-for-age Z-score (WMD = 0.02, 95%CI: -0.01-0.06) or weight-for-height Z score (WMD = 0.02, 95%CI: -0.03-0.06). Child age at zinc supplementation appeared to modify the effects on height (P-interaction = 0.002) and HAZ (P-interaction = 0.06), with larger effects of supplementation starting at age ≥2 years (WMD for height = 1.37 cm, 95%CI: 0.50-2.25; WMD for HAZ = 0.12, 95%CI: 0.05-0.19). No significant effects of supplementation were found on the risk of stunting, underweight or wasting; (4) Conclusion: Although the possibility of publication bias and small study effect could not be excluded, the current meta-analysis indicates that zinc supplementation in infants and early childhood, but not pregnancy, increases specific growth outcomes, with evidence for a potentially stronger effect after 2 years of age. These findings inform recommendation and policy development for zinc supplementation to improve growth among young children.

Choosing Anthropometric Indicators to Monitor the Response to Treatment for Severe Acute Malnutrition in Rural Southern Ethiopia-Empirical Evidence

The World Health Organization (WHO) recommends the assessment of nutritional recovery using the same anthropometric indicator that was used to diagnose severe acute malnutrition (SAM) in children. However, related empirical evidence from low-income countries is lacking. Non-oedematous children (n = 661) aged 6-59 months admitted to a community-based outpatient therapeutic program for SAM in rural southern Ethiopia were studied. The response to treatment in children admitted to the program based on the mid-upper arm circumference (MUAC) measurement was defined by calculating the gains in average MUAC and weight during the first four weeks of treatment. The children showed significant anthropometric changes only when assessed with the same anthropometric indicator used to define SAM at admission. Children with the lowest MUAC at admission showed a significant gain in MUAC but not weight, and children with the lowest weight-for-height/length (WHZ) showed a significant gain in weight but not MUAC. The response to treatment was largest for children with the lowest anthropometric status at admission in either measurement. MUAC and weight gain are two independent anthropometric measures that can be used to monitor sufficient recovery in children treated for SAM. This study provides empirical evidence from a low-income country to support the recent World Health Organization recommendation.

Monitoring and discharging children being treated for severe acute malnutrition using mid-upper arm circumference: secondary data analysis from rural Gambia

Background

Severe acute malnutrition (SAM) is a major public health problem. Mid-upper arm circumference (MUAC) is widely used to admit children to treatment programmes. However, insufficient data supporting MUAC discharge criterion limits its use as a stand-alone tool. Our aim was to evaluate MUAC for monitoring nutritional recovery and discharge.

Methods

This was a secondary analysis of clinical data from children 6-59 months-old treated for SAM from January 2003 to December 2013 at the Nutritional Rehabilitation Unit in rural Gambia. Weight, weight-for-height z-score (WHZ) and MUAC response to treatment were assessed. Treatment indicators and regression models controlled for admission measurement and age were compared by discharge MUAC and WHZ.

Results

Four hundred and sixty-three children with marasmus were included. MUAC, WHZ and weight showed parallel responses to treatment. MUAC≥125 mm as a discharge criterion performed well, showing good prediction of default and referral to hospital, acceptable duration of stay, and a higher absolute MUAC measure compared to WHZ≥-2.00, closely related to lower risk of mortality.

Conclusions

MUAC can be used as a standalone tool for monitoring nutritional recovery. MUAC≥125 mm performs well as a discharge criterion; however, follow-up data is needed to assess its safety. Further research is needed on children meeting MUAC discharge criterion but with WHZ≤2.0.

Diagnostic criteria for severe acute malnutrition among infants aged under 6 mo

Background: There is an increasing recognition of malnutrition among infants under 6 mo of age (U6M). Current diagnosis criteria use weight-for-length z scores (WLZs), but the 2006 WHO standards exclude infants shorter than 45 cm. In older children, midupper arm circumference (MUAC) predicts mortality better than does WLZ. Outcomes may also be influenced by exposure to HIV and size or gestational age at birth. Diagnostic thresholds for WLZ, MUAC, and other indexes have not been fully evaluated against mortality risk among U6M infants.Objective: The aim was to determine the association of anthropometric indexes with risks of inpatient and postdischarge mortality among U6M infants recruited at the time of hospitalization.Design: We analyzed data from a cohort of U6M infants admitted to Kilifi County Hospital (2007-2013), Kenya. The primary outcomes were inpatient death and death during follow-up over 1 y after discharge. We calculated adjusted RRs for inpatient mortality and HRs for postdischarge mortality for different anthropometric measures and thresholds. Discriminatory value was assessed by using receiver operating characteristic curves.Results: A total of 2882 infants were admitted: 140 (4.9%) died in the hospital and 1405 infants were followed up after discharge. Of these, 75 (5.3%) died within 1 y during 1318 child-years of observation. MUAC and weight-for-age z score (WAZ) predicted inpatient and postdischarge mortality better than did WLZ (P < 0.0001). A single MUAC threshold of <11.0 cm performed similarly to MUAC thresholds that varied with age (all P > 0.05) and performed better than WLZ <-3 for both inpatient and postdischarge mortality (both P < 0.001). Reported small size at birth did not reduce the risk of death associated with anthropometric indexes.Conclusions: U6M infants at the highest risk of death are best targeted by using MUAC or WAZ. Further research into the effectiveness of potential interventions is required.

Admission profile and discharge outcomes for infants aged less than 6 months admitted to inpatient therapeutic care in 10 countries. A secondary data analysis

Evidence on the management of acute malnutrition in infants aged less than 6 months (infants <6mo) is scarce. To understand outcomes using current protocols, we analysed a sample of 24 045 children aged 0-60 months from 21 datasets of inpatient therapeutic care programmes in 10 countries. We compared the proportion of admissions, the anthropometric profile at admission and the discharge outcomes between infants <6mo and children aged 6-60 months (older children). Infants <6mo accounted for 12% of admissions. The quality of anthropometric data at admission was more problematic in infants <6mo than in older children with a greater proportion of missing data (a 6.9 percentage point difference for length values, 95% CI: 6.0; 7.9, P < 0.01), anthropometric measures that could not be converted to indices (a 15.6 percentage point difference for weight-for-length z-score values, 95% CI: 14.3; 16.9, P < 0.01) and anthropometric indices that were flagged as outliers (a 2.7 percentage point difference for any anthropometric index being flagged as an outlier, 95% CI: 1.7; 3.8, P < 0.01). A high proportion of both infants <6mo and older children were discharged as recovered. Infants <6mo showed a greater risk of death during treatment (risk ratio 1.30, 95% CI: 1.09; 1.56, P < 0.01). Infants <6mo represent an important proportion of admissions to therapeutic feeding programmes, and there are crucial challenges associated with their care. Systematic compilation and analysis of routine data for infants <6mo is necessary for monitoring programme performance and should be promoted as a tool to monitor the impact of new guidelines on care.

Mid-upper arm circumference v. weight-for-height Z-score for predicting mortality in hospitalized children under 5 years of age

OBJECTIVE

To compare the performance of mid-upper arm circumference (MUAC) against weight-for-height Z-score (WHZ) for predicting inpatient deaths in children under 5 years of age.

DESIGN

Diagnostic test accuracy study.

SETTING

Paediatric emergency department of a tertiary care hospital catering to semi-urban and rural population in Delhi, India.

SUBJECTS

Hospitalized children (n 1663) aged 6 months to 5 years, for whom discharge outcome was available, were consecutively recruited over 14 months. MUAC (cm), weight (kg) height (cm), clinical details and the outcome were recorded. MUAC (index test) was compared with WHZ based on the WHO growth standards (reference test) for predicting the outcome.

RESULTS

One hundred and twenty-four (7 %) children died during hospital stay. Both MUAC < 11·5 cm (adjusted OR (95 % CI): 3·7 (2·43, 5·60), P<0·001) and WHZ<-3 (2·0 (1·37, 2·99), P<0·001) served as independent predictors of inpatient mortality. However, MUAC was a significantly better predictor of mortality compared with WHZ in terms of area under the receiver-operating characteristic curve (MUAC=0·698, WHZ=0·541, P<0·001). MUAC<11·5 cm had the best trade-off of sensitivity and specificity for predicting inpatient mortality. A combination of WHZ<-3 and/or MUAC<11·5 cm did not significantly improve the predictive value over that of MUAC/WHZ, assessed individually.

CONCLUSION

MUAC<11·5 cm is a better predictor of mortality in hospitalized under-5 children, as compared with WHZ<-3. It should be measured in all emergency settings to identify the children at higher risk of death.

Current MUAC Cut-Offs to Screen for Acute Malnutrition Need to Be Adapted to Gender and Age: The Example of Cambodia

Background

Early identification of children <5 yrs with acute malnutrition is a priority. Acute malnutrition is defined by the World Health Organization as a mid-upper-arm circumference (MUAC) <12.5 cm or a weight-for-height Z-score (WHZ) <-2. MUAC is a simple and low-cost indicator to screen for acute malnutrition in communities, but MUAC cut-offs currently recommended by WHO do not identify the majority of children with weight-for-height Z-score (<-2 (moderate malnourished) or r<-3 (severe malnourished). Also, no cut-offs for MUAC are established for children >5 yrs. Therefore, this study aimed at defining gender and age-specific cut-offs to improve sensitivity of MUAC as an indicator of acute malnutrition.

Methods

To establish new age and gender-specific MUAC cut-offs, pooled data was obtained for 14,173 children from 5 surveys in Cambodia (2011–2013). Sensitivity, false positive rates, and areas under receiver-operator characteristic curves (AUC) were calculated using wasting for children <5yrs and thinness for children ≥5yrs as gold standards. Among the highest values of AUC, the cut-off with the highest sensitivity and a false positive rate ≤33% was selected as the optimal cut-off.

Results

Optimal cut-off values increased with age. Boys had higher cut-offs than girls, except in the 8–10.9 yrs age range. In children <2yrs, the cut-off was lower for stunted children compared to non stunted children. Sensitivity of MUAC to identify WHZ<-2 and <-3 z-scores increased from 24.3% and 8.1% to >80% with the new cut-offs in comparison with the current WHO cut-offs.

Conclusion

Gender and age specific MUAC cut-offs drastically increased sensitivity to identify children with WHZ-score <-2 z-scores. International reference of MUAC cut-offs by age group and gender should be established to screen for acute malnutrition at the community level.

Acute malnutrition among under-five children in Faryab, Afghanistan: prevalence and causes

Acute malnutrition affects more than 50 million under-five (U5) children, causing 8.0% of global child deaths annually. The prevalence of acute malnutrition (wasting) among U5 children in Afghanistan was 9.5% nationally and 3.7% in Faryab province in 2013. A cross-sectional study was conducted for 600 households in Faryab to find the prevalence and causes of acute malnutrition. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using a logistic model. Demographic results of this study showed that 54.0% of the household heads and 92.3% of the mothers had no education. Three-fourths of households had a monthly income ≤ 250 USD. According to the measurement of weight for height Z-score (WHZ), 35.0% (210/600) of the children had acute malnutrition (wasting, WHZ < -2). In more than half of the households, water, sanitation, and hygiene (WASH) conditions were poor. When adjusted, a significant association of acute malnutrition among U5 children was found with the education level of household heads (OR=1.49; 95% CI, 1.02-2.17), age of household heads (OR=2.01; 95% CI, 1.21-3.35), income (OR=1.66; 95% CI, 1.04-2.27), education level of mothers (OR=2.21; 95% CI, 1.00-4.88), age of children (OR=1.99; 95% CI, 1.32-2.93), history of children with diarrhea in the last two weeks of data collection (OR=1.57; 95% CI, 1.10-2.27), feeding frequency (OR=3.01; 95% CI, 1.21-7.46), water sources (OR=1.89; 95% CI, 1.26-2.83), and iodized salt (OR=0.59; 95% CI, 0.39-0.88). The present study indicated that an increase in education level of parents, household income, and quality of WASH would result in a significant decrease in prevalence of wasting among U5 children.

Management of acute malnutrition in infants aged under 6 months (MAMI): current issues and future directions in policy and research

BACKGROUND

Globally, some 4.7 million infants aged under 6 months are moderately wasted and 3.8 million are severely wasted. Traditionally, they have been over-looked by clinicians, nutritionists, and policy makers.

OBJECTIVE

To present evidence and arguments for why treating acute malnutrition in infants under 6 months of age is important and outline some of the key debates and research questions needed to advance their care.

METHODS

Narrative review.

RESULTS AND CONCLUSIONS

Treating malnourished infants under 6 months of age is important to avoid malnutrition-associated mortality in the short-term and adverse health and development outcomes in the long-term. Physiological and pathological differences demand a different approach from that in older children; key among these is a focus on exclusive breastfeeding wherever possible. New World Health Organization guidelines for the management of severe acute malnutrition (SAM) include this age group for the first time and are also applicable to management of moderate acute malnutrition (MAM). Community-based breastfeeding support is the core, but not the sole, treatment. The mother-infant dyad is at the heart of approaches, but wider family and community relationships are also important. An urgent priority is to develop better case definitions; criteria based on mid-upper-arm circumference (MUAC) are promising but need further research. To effectively move forward, clinical trials of assessment and treatment are needed to bolster the currently sparse evidence base. In the meantime, nutrition surveys and screening at health facilities should routinely include infants under 6 months of age in order to better define the burden and outcomes of acute malnutrition in this age group.