Practical Application of Linear Growth Measurements in Clinical Research in Low- and Middle-Income Countries

Ductal stenting vs. surgical shunting in late presenting duct-dependent pulmonary circulation: a single-center experience

Introduction

PDA stenting is an option to mBTT shunt for younger patients; nevertheless, few reports of this palliative approach have been made for the late presenter population, especially for patients who are older than 30 days but under 5 years. This study aimed to evaluate the clinical result and intra-hospital costs of ductal stenting in late-presenting patients in comparison to surgical shunting.

Methods

A single-center, retrospective cohort study was conducted from August 2016 to August 2022. This study included patients with pulmonary duct dependent CHD who were hospitalized for palliative therapy. The extracted data were baseline characteristics, clinical findings, supportive examination findings, complications, outcomes, and length of stay of the patients. Monitoring was carried out during treatment up to 30 days after the procedure.

Results

A total of 143 patients were included in the analysis; 43 patients underwent PDA stent and 100 patients underwent mBTT shunt with median age of PDA stent group 110 (31-1,498) days and mBTT shunt group 174.5 (30-1,651) days. Primary outcome composite was not significant in both groups including 30 days mortality [6 (14%) vs. 14 (14%), p = 1.000], reintervention [1 (2.3%) vs. 7 (7%), p = 0.436], and 30 days rehospitalization [0 (0%) vs. 2 (2%), p = 0.319]. Secondary outcome analysis showed shorter ICU length of stay in the PDA stent group [2 (0-16) days vs. 4 (1-63) days, p = 0.002].

Conclusions

PDA stent has an outcome that is non inferior from the mBTT shunt procedure in the composite outcome including 30 days mortality, reintervention, and 30 days rehospitalization but significantly lower in ICU length of stay.

Postnatal growth in small vulnerable newborns: a longitudinal study of 2 million Brazilians using routine register-based linked data

BACKGROUND

Preterm, low-birth weight (LBW) and small-for-gestational age (SGA) newborns have a higher frequency of adverse health outcomes, including linear and ponderal growth impairment.

OBJECTIVE

To describe the growth trajectories and to estimate catch-up growth during the first 5 y of life of small newborns according to 3 vulnerability phenotypes (preterm, LBW, SGA).

METHODS

Longitudinal study using linked data from the 100 Million Brazilian Cohort baseline, the Brazilian National Live Birth System (SINASC), and the Food and Nutrition Surveillance System (SISVAN) from 2011 to 2017. We estimated the length/height-for-age (L/HAZ) and weight-for-age z-score (WAZ) trajectories from children of 6-59 mo using the linear mixed model for each vulnerable newborn phenotype. Growth velocity for both L/HAZ and WAZ was calculated considering the change (Δ) in the mean z-score between 2 time points. Catch-up growth was defined as a change in z-score > 0.67 at any time during follow-up.

RESULTS

We analyzed 2,021,998 live born children and 8,726,599 observations. The prevalence of at least one of the vulnerable phenotypes was 16.7% and 0.6% were simultaneously preterm, LBW, and SGA. For those born at term, all phenotypes had a period of growth recovery from 12 mo. For preterm infants, the onset of L/HAZ growth recovery started later at 24 mo and the growth trajectories appear to be lower than those born at term, a condition aggravated among children with the 3 phenotypes. Preterm and female infants seem to experience slower growth recovery than those born at term and males. The catch-up growth occurs at 24-59 mo for males preterm: preterm + AGA + NBW (Δ = 0.80), preterm + AGA + LBW (Δ = 0.88), and preterm + SGA + LBW (Δ = 1.08); and among females: term + SGA + NBW (Δ = 0.69), term + AGA + LBW (Δ = 0.72), term + SGA + LBW (Δ = 0.77), preterm + AGA + LBW (Δ = 0.68), and preterm + SGA + LBW (Δ = 0.83).

CONCLUSIONS

Children born preterm seem to reach L/HAZ and WAZ growth trajectories lower than those attained by children born at term, a condition aggravated among the most vulnerable.

Impact of anthropometry training and feasibility of 3D imaging on anthropometry data quality among children under five years in a postmortem setting

BACKGROUND

The Child Health and Mortality Prevention Surveillance Network (CHAMPS) identifies causes of under-5 mortality in high mortality countries.

OBJECTIVE

To address challenges in postmortem nutritional assessment, we evaluated the impact of anthropometry training and the feasibility of 3D imaging on data quality within the CHAMPS Kenya site.

DESIGN

Staff were trained using World Health Organization (WHO)-recommended manual anthropometry equipment and novel 3D imaging methods to collect postmortem measurements. Following training, 76 deceased children were measured in duplicate and were compared to measurements of 75 pre-training deceased children. Outcomes included measures of data quality (standard deviations of anthropometric indices and digit preference scores (DPS)), precision (absolute and relative technical errors of measurement, TEMs or rTEMs), and accuracy (Bland-Altman plots). WHO growth standards were used to produce anthropometric indices. Post-training surveys and in-depth interviews collected qualitative feedback on measurer experience with performing manual anthropometry and ease of using 3D imaging software.

RESULTS

Manual anthropometry data quality improved after training, as indicated by DPS. Standard deviations of anthropometric indices exceeded limits for high data quality when using the WHO growth standards. Reliability of measurements post-training was high as indicated by rTEMs below 1.5%. 3D imaging was highly correlated with manual measurements; however, on average 3D scans overestimated length and head circumference by 1.61 cm and 2.27 cm, respectively. Site staff preferred manual anthropometry to 3D imaging, as the imaging technology required adequate lighting and additional considerations when performing the measurements.

CONCLUSIONS

Manual anthropometry was feasible and reliable postmortem in the presence of rigor mortis. 3D imaging may be an accurate alternative to manual anthropometry, but technology adjustments are needed to ensure accuracy and usability.

The Effects of Yogurt Supplementation and Nutritional Education on Malnourished Infants: A Pilot RCT in Dhaka's Slums

Our objective was to quantify the effects of yogurt supplementation and nutrition education over three months on the linear growth of infants at risk of stunting. We conducted a three-arm pilot randomized controlled trial: (1) nutrition education for mothers; (2) nutrition education plus a daily yogurt supplement (50 g) for the index child; and (3) usual care (control). Dyads of children aged 4-6 months and at risk of stunting [length-for-age z-score (LAZ) ≤ -1 SD and >-2 SD] and their mothers with ≤10 years of education were eligible for the study. Participants were recruited from five slum areas in Dhaka, Bangladesh. Intention-to-treat (N = 162) and complete-case analyses (N = 127) showed no between-group statistically significant differences in LAZ or weight-for-age (WAZ). However, the yogurt group showed greater change in linear growth compared to the control (LAZ: mean difference 0.20, 95% CI: -0.06, 0.47, p-value 0.13), which was also slightly greater than the education-only group. Children in the yogurt plus group were five times (95% CI: 0.80, 31.80, p-value 0.09) more likely to meet the minimum dietary diversity (MDD) score compared to the control. A 3-month follow-up of this pilot study did not demonstrate that yogurt was beneficial to linear growth. However, there were encouraging trends that merit replication of the intervention with larger samples and longer follow-ups.

The association between plasma choline, growth and neurodevelopment among Malawian children aged 6-15 months enroled in an egg intervention trial

Choline is an essential micronutrient that may influence growth and development; however, few studies have examined postnatal choline status and children's growth and development in low- and middle-income countries. The aim of this observational analysis was to examine associations of plasma choline with growth and development among Malawian children aged 6-15 months enrolled in an egg intervention trial. Plasma choline and related metabolites (betaine, dimethylglycine and trimethylamine N-oxide) were measured at baseline and 6-month follow-up, along with anthropometric (length, weight, head circumference) and developmental assessments (the Malawi Developmental Assessment Tool [MDAT], the Infant Orienting with Attention task [IOWA], a visual paired comparison [VPC] task and an elicited imitation [EI] task). In cross-sectional covariate-adjusted models, each 1 SD higher plasma choline was associated with lower length-for-age z-score (-0.09 SD [95% confidence interval, CI -0.17 to -0.01]), slower IOWA response time (8.84 ms [1.66-16.03]) and faster processing speed on the VPC task (-203.5 ms [-366.2 to -40.7]). In predictive models, baseline plasma choline was negatively associated with MDAT fine motor z-score at 6-month follow-up (-0.13 SD [-0.22 to -0.04]). There were no other significant associations of plasma choline with child measures. Similarly, associations of choline metabolites with growth and development were null except higher trimethylamine N-oxide was associated with slower information processing on the VPC task and higher memory scores on the EI task. In this cohort of children with low dietary choline intake, we conclude that there were no strong or consistent associations between plasma choline and growth and development.

Child development with the D-score: turning milestones into measurement

The chapter equips the reader with a basic understanding of robust psychometric methods that are needed to turn developmental milestones into measurements, introducing the fundamental issues in defining a unit for child development and demonstrates the relevant quantitative methodology. It reviews quantitative approaches to measuring child development;introduces the Rasch model in a non-technical way;shows how to estimate model parameters from real data;puts forth a set of principles for model evaluation and assessment of scale quality;analyses the relation between early D-scores and later intelligence;and compares the D-scores from three studies that all use the same instrument.

Design of the performance outcome scoring template (POS-T) with example application on CO2 emissions reduction amongst 36 OECD member countries

In applied program settings, such as in natural environment control and education, performance evaluation is usually conducted by evaluators considering both self-comparison and comparison with peers. We have developed the performance outcome scoring template (POS-T) for assessments with high face-validity in these settings. POS-T puts achievements of individuals or groups in context, i.e. the resulting performance outcome score (POS) reflects a meaningful measure of performance magnitude with regards to internal and external comparisons. Development of a POS is performed in four steps supported by a statistical framework. Software is supplied for creation of scoring applications in different performance evaluation settings. We demonstrate the POS-T by evaluation of CO₂ emissions reduction amongst 36 OECD member countries.

Guidance for Systematic Integration of Undernutrition in Attributing Cause of Death in Children

Minimally invasive tissue sampling (MITS) is increasingly being used to better understand causes of death in low-resource settings. Undernutrition (eg, wasting, stunting) is prevalent among children globally and yet not consistently coded or uniformly included on death certificates in MITS studies when present. Consistent and accurate attribution of undernutrition is fundamental to understanding its contribution to child deaths. In May 2020, members of the MITS Alliance Cause of Death Technical Working Group convened a panel of experts in public health, child health, nutrition, infectious diseases, and MITS to develop guidance for systematic integration of undernutrition, as assessed by anthropometry, in cause of death coding, including as part of the causal chain or as a contributing condition, in children <5 years of age. The guidance presented here will support MITS and other researchers, public health practitioners, and clinicians with a systematic approach to assigning and interpreting undernutrition in death certification.

Do children in India grow well into adolescents? Longitudinal analysis of growth transitions from Young Lives panel survey in India

OBJECTIVES

Studies that examined the growth during late childhood and early adolescence beyond 8 years of age are very limited. Further, most studies have used dichotomized classification of stunting, thereby limiting the understanding of moderate stunting in childhood growth trajectory. We aimed to examine the course of stunting from childhood to adolescence by undertaking robust analyses of the Young Lives Survey (YLS) longitudinal data from India using multilevel categorization of stunting.

STUDY DESIGN

Retrospective cohort analysis was undertaken from YLS in India among 1827 children from the younger cohort born in 2001-02 with complete follow-up data in all five rounds of YLS collected in 2002, 2006, 2009, 2013, and 2016.

METHODS

A three-state multistate Markov model (not stunted, moderate, severe) was performed to estimate annual transition probabilities, mean sojourn-time, and transition-specific risk factors.

RESULTS

Between Round-one and Round-five, cross-sectional prevalence of severe stunting decreased from 10.4% (95% confidence interval [CI]: 7.8%, 13.7%) to 5.3% (95% CI: 3.8%, 7.3%), while moderate stunting increased from 19.9% (95% CI: 16.3%,23.9%) to 21.7% (95% CI: 18.4%, 24.9%). Mean Sojourn time estimation indicated a relatively concise state for moderate stunting. The stunting trajectory had shown gender differential where more faltering to severe stunting and lower recovery to the normal state was observed among girls between 8 and 12 years and among boys between 12 and 15 years. Compared with boys, girls had 40% excess likelihood (Hazard Ratio: 1.40; 95% CI 1.00 to 1.95) for moderate-to-severe stunting transition and also had 19% excess likelihood (Hazard Ratio: 1.19; 95% CI 1.01 to 1.40) of favorable transition (moderate-to-non-stunted).

CONCLUSIONS

The transition trajectory highlights preadolescence, especially among girls, as an additional window of opportunity to ensure better nutrition in adolescent life. With a fifth of adolescents living in India, study findings call for coordinated, multisectoral, age-appropriate, and gender-responsive approach to take India closer to meeting SDG-2.

A Locally-Produced Plant-Based Supplement Swathi Savi (SAVI) Enrichment Improves Body Growth, Bone Development, and Immune Functions in Protein Malnourished Mice: Implications for Strategies to Combat Child Malnutrition

Child malnutrition is a critical global challenge. India alone is home to nearly 46 million stunted children, a third of the world's total. Supplementing locally-produced foods has been acknowledged as a sustainable strategy for combating child malnutrition. We used an established protein malnutrition (PM) model in young mice to evaluate the safety and efficacy of the SAVI-enriched diet as a food supplement to combat child malnutrition in India. Results indicate that feeding the SAVI-enriched diet improves body weight, lean muscle mass, bone, and immune health in PM young mice. Based on the results of our study in mice, we suggest future human trials to examine the supplement's potential benefits for humans.

Comparing growth velocity of HIV exposed and non-exposed infants: An observational study of infants enrolled in a randomized control trial in Zambia

BACKGROUND

Impaired growth among infants remains one of the leading nutrition problems globally. In this study, we aimed to compare the growth trajectory rate and evaluate growth trajectory characteristics among children, who are HIV exposed uninfected (HEU) and HIV unexposed uninfected (HUU), under two years in Zambia.

METHOD

Our study used data from the ROVAS II study (PACTR201804003096919), an open-label randomized control trial of two verses three doses of live, attenuated, oral RotarixTM administered 6 &10 weeks or at 6 &10 weeks plus an additional dose at 9 months of age, conducted at George clinic in Lusaka, Zambia. Anthropometric measurements (height and weight) were collected on all scheduled and unscheduled visits. We defined linear growth velocity as the rate of change in height and estimated linear growth velocity as the first derivative of the mixed effect model with fractional polynomial transformations and, thereafter, used the second derivative test to determine the peak height and age at peak heigh.

RESULTS

We included 212 infants in this study with median age 6 (IQR: 6-6) weeks of age. Of these 97 (45.3%) were female, 35 (16.4%) were stunted, and 59 (27.6%) were exposed to HIV at baseline. Growth velocity was consistently below the 3rd percentile of the WHO linear growth standard for HEU and HUU children. The peak height and age at peak height among HEU children were 74.7 cm (95% CI = 73.9-75.5) and 15.5 months (95% CI = 14.7-16.3) respectively and those for HUU were 73 cm (95% CI = 72.1-74.0) and 15.6 months (95% CI = 14.5-16.6) respectively.

CONCLUSION

We found no difference in growth trajectories between infants who are HEU and HUU. However, the data suggests that poor linear growth is universal and profound in this cohort and may have already occurred in utero.

Normal growth variance by Z scores should be considered when interpreting the growth inhibitory effect of inhaled corticosteroids

BACKGROUND

Randomized clinical trials suggest that long-term inhaled corticosteroid (ICS) treatment significantly inhibits growth velocity (GV) assessed by centimeters/year (cm/year) in primarily prepubescent, mild asthmatics. However, several observational studies measuring normal growth variance by Z score suggest the absence of the ICS inhibitory effect.

OBJECTIVE

To demonstrate the generalizability of ICS growth inhibition in cm/year by establishing whether this measure exceeds the expected normal changes in GV by Z score for similar age and sex.

METHODS

This was a retrospective, observational study comparing height and GV across a 2 year period in asthmatics aged 2-10 years, receiving ICS therapy (Group 3) with non-asthmatics, and non-ICS asthmatics (Groups 1 and 2), respectively. Generalized linear model procedure compared GV measures after adjustment for age, gender, and dependence of group differences on the age of the child.

RESULTS

Before initiation of ICS therapy at baseline, Group 3 patients (n = 22) were shorter than Groups 1 (n = 67) and 2 (n = 44) by mean height in cm, and height for age Z score in the adjusted model (p < .05). GV was also significantly reduced in Group 3 after initiation of ICS therapy versus Groups 1 and 2 by 1.0-1.5 cm/year, respectively, p < .05, but not significantly in comparison to expected normal GV variance determined by Z score, p ≥ .05.

CONCLUSION

Our findings suggest the need to consider normal growth variance by Z scores in addition to absolute changes (cm/year) when interpreting the inhibitory effect of ICS on GV. Larger sample size studies will be necessary to confirm our findings.

Child development with the D-score: turning milestones into measurement

The chapter equips the reader with a basic understanding of robust psychometric methods that are needed to turn developmental milestones into measurements, introducing the fundamental issues in defining a unit for child development and demonstrates the relevant quantitative methodology. It reviews quantitative approaches to measuring child development;introduces the Rasch model in a non-technical way;shows how to estimate model parameters from real data;puts forth a set of principles for model evaluation and assessment of scale quality;analyses the relation between early D-scores and later intelligence;and compares the D-scores from three studies that all use the same instrument.

A multilevel analysis of individual, household and community level factors on stunting among children aged 6-59 months in Eswatini: A secondary analysis of the Eswatini 2010 and 2014 Multiple Indicator Cluster Surveys

Introduction

Child stunting is a significant public health problem in Eswatini. It is associated with a range of child health outcomes, including morbidity, physical and cognitive growth.

Objective

To determine the individual, household, and community-level factors associated with child stunting in Eswatini in 2010 and 2014.

Methods

Using the Eswatini Multiple Indicator Cluster Surveys conducted in 2010 and 2014, a secondary analysis was done of the children surveyed, aged 6–59 months. A total of 1,891 were surveyed in 2010, and 1,963 children in 2014. Univariate, bivariable analysis and multivariable multilevel logistic regression were used to establish the factors associated with stunting.

Results

The study found that stunting decreased significantly between 2010 and 2014, from 31.4% to 25.5% (p<0.001). In both 2010 and 2014, lower odds of stunting were observed among female children, in children born to women with tertiary education compared to those born to women with no formal education. Lower odds of stunting were observed among children from rich households compared to poorest households. In both 2010 and 2014, increased odds of stunting were observed among children aged 12–23, 24–35 and 36–47 months compared to children aged 6–11 months. At the household level, higher odds of stunting were observed among children from households with two and more children under five years of age compared to those with only one child and in 2010, among children from households with a pit latrine and no toilet facility compared to households with a flush toilet. At the community level, in 2010, higher odds of stunting were observed among children from the Shiselweni compared to those from the Lubombo region.

Conclusion

The findings highlight the individual, household, and community-level factors significantly associated with stunting and the changes between the two surveys.

Improving assessment of child growth in a pediatric hospital setting

BACKGROUND

Accurate anthropometric measurements are essential for assessing nutritional status, monitoring child growth, and informing clinical care. We aimed to improve height measurements of hospitalized pediatrics patients through implementation of gold standard measurement techniques.

METHODS

A quality improvement project implemented computerized training modules on anthropometry and standardized wooden boards for height measurements in a tertiary children's hospital. Heights were collected pre- and post-intervention on general pediatric inpatients under 5 years of age. Accuracy of height measurements was determined by analyzing the variance and by comparing to World Health Organization's defined biologically plausible height-for-age z-scores. Qualitative interviews assessed staff attitudes.

RESULTS

Ninety-six hospital staff completed the anthropometry training. Data were available on 632 children pre- and 933 post-intervention. Training did not increase the proportion of patients measured for height (78.6% pre-intervention vs. 75.8% post-intervention, p = 0.19). Post-intervention, wooden height boards were used to measure height of 34.8% patients, while tape measures and wingspan accounted for 42.0% and 3.5% of measurements, respectively. There was no improvement in the quality of height measurements based on plausibility (approximately 3% height-for-age z-scores measurements flagged out of range pre- and post-intervention), digit preference (13.4% of digits pre- and 12.3% post-intervention requiring reclassification), or dispersion of measurements (height-for-age z-scores standard deviation 1.9 pre- and post-intervention). Staff reported that using the wooden board was too labor consuming and cumbersome.

CONCLUSIONS

Our findings suggest that efforts to improve anthropometric measurements of hospitalized children have multiple obstacles, and further investigation of less cumbersome methods of measurements may be warranted.

Schincaglia R, G. Peixoto MDR, C. M. Hadler MC. Multiple Micronutrient Powder Reduces Vitamin E Deficiency in Brazilian Children: A Pragmatic, Controlled Clinical Trial

Multiple micronutrient powder supplementation is a health promotion strategy, but data on its effectiveness regarding vitamin E are rare. The objective was to evaluate the impact of home fortification with powdered micronutrients on α-tocopherol concentrations, growth, and inflammation in Brazilian children aged 6–15 months. This is a pragmatic, controlled clinical trial, in which the intervention group received micronutrient powder sachets for up to 3 months. Vitamin E deficiency was considered when α-tocopherol was less than 11.6 µmol/L. The Poisson regression model was used to estimate adjusted values for prevalence ratios (PR) for the outcome variable. A total of 224 children participated in the study. The intervention group had a higher median α-tocopherol level (17.2 versus 3.6 µmol/L; p < 0.001) and an 82.0% reduction in the prevalence of vitamin deficiency (PR = 0.18; 95% CI 0.11–0.30) when compared with the control group. Consumption of multiple micronutrients in powder increases serum α-tocopherol concentrations, promotes better linear growth, and reduces morbidity in children.

Study of Environmental Enteropathy and Malnutrition (SEEM) in Pakistan: protocols for biopsy based biomarker discovery and validation

Background

Environmental Enteropathy (EE), characterized by alterations in intestinal structure, function, and immune activation, is believed to be an important contributor to childhood undernutrition and its associated morbidities, including stunting. Half of all global deaths in children < 5 years are attributable to under-nutrition, making the study of EE an area of critical priority.

Methods

Community based intervention study, divided into two sub-studies, 1) Longitudinal analyses and 2) Biopsy studies for identification of EE features via omics analyses. Birth cohorts in Matiari, Pakistan established: moderately or severely malnourished (weight for height Z score (WHZ) < − 2) children, and well-nourished (WHZ > 0) children. Blood, urine, and fecal samples, for evaluation of potential biomarkers, will be collected at various time points from all participants (longitudinal analyses). Participants will receive appropriate educational and nutritional interventions; non-responders will undergo further evaluation to determine eligibility for further workup, including upper gastrointestinal endoscopy. Histopathological changes in duodenal biopsies will be compared with duodenal biopsies obtained from USA controls who have celiac disease, Crohn’s disease, or who were found to have normal histopathology. RNA-Seq will be employed to characterize mucosal gene expression across groups. Duodenal biopsies, luminal aspirates from the duodenum, and fecal samples will be analyzed to define microbial community composition (omic analyses). The relationship between histopathology, mucosal gene expression, and community configuration will be assessed using a variety of bioinformatic tools to gain better understanding of disease pathogenesis and to identify mechanism-based biomarkers. Ethical review committees at all collaborating institutions have approved this study. All results will be made available to the scientific community.

Discussion

Operational and ethical constraints for safely obtaining intestinal biopsies from children in resource-poor settings have led to a paucity of human tissue-based investigations to understand and reverse EE in vulnerable populations. Furthermore, EE biomarkers have rarely been correlated with gold standard histopathological confirmation. The Study of Environmental Enteropathy and Malnutrition (SEEM) is designed to better understand the pathophysiology, predictors, biomarkers, and potential management strategies of EE to inform strategies to eradicate this debilitating pathology and accelerate progress towards the 2030 Sustainable Development Goals.

Trial registration

Retrospectively registered; clinicaltrials.gov ID NCT03588013.

Electronic supplementary material

The online version of this article (10.1186/s12887-019-1564-x) contains supplementary material, which is available to authorized users.

Factors associated with recovery from stunting among under-five children in two Nairobi informal settlements

Childhood stunting is a public health concern in many low-and-middle income countries, as it is associated with both short-term and long-term negative effects on child cognitive development, physical health, and schooling outcomes. There is paucity of studies on recovery from stunting among under five children in these countries. Most studies focused on the recovery much later in adolescence. We used longitudinal data from two Nairobi urban settlements to determine the incidence of recovery from stunting and understand the factors associated with post-stunting linear growth among under-five children. A total of 1,816 children were recruited between birth and 23 months and were followed-up until they reached five years. We first looked at the time to recover from stunting using event history analysis and Cox regression. Second, we used height-for-age z-score slope modelling to estimate the change in linear growth among children who were stunted. Finally, we fitted a linear regression model of the variation in HAZ on a second degree fractional polynomials in child’s age to identify the factors associated with post-stunting linear growth. The principal findings are: i) the incidence of recovery from stunting was 45% among stunted under-five children in the two settlements; ii) timely child immunization, age at stunting, mother’s parity and household socioeconomic status are important factors associated with time to recover from stunting within the first five years of life; and iii) child illness status and age at first stunting, mother’s parity and age have a strong influence on child post-stunting linear growth. Access to child health services and increased awareness among health professionals and child caregivers, would be critical in improving child growth outcomes in the study settings. Additionally, specific maternal and reproductive health interventions targeting young mothers in the slums may be needed to reduce adolescent and young mother’s vulnerability and improve their child health outcomes.

Accuracy and reliability of a low-cost, handheld 3D imaging system for child anthropometry

The usefulness of anthropometry to define childhood malnutrition is undermined by poor measurement quality, which led to calls for new measurement approaches. We evaluated the ability of a 3D imaging system to correctly measure child stature (length or height), head circumference and arm circumference. In 2016–7 we recruited and measured children at 20 facilities in and around metro Atlanta, Georgia, USA; including at daycare, higher education, religious, and medical facilities. We selected recruitment sites to reflect a generally representative population of Atlanta and to oversample newborns and children under two years of age. Using convenience sampling, a total of 474 children 0–5 years of age who were apparently healthy and who were present at the time of data collection were included in the analysis. Two anthropometrists each took repeated manual measures and repeated 3D scans of each child. We evaluated the reliability and accuracy of 3D scan-derived measurements against manual measurements. The mean child age was 26 months, and 48% of children were female. Based on reported race and ethnicity, the sample was 42% Black, 28% White, 8% Asian, 21% multiple races, other or race not reported; and 16% Hispanic. Measurement reliability of repeated 3D scans was within 1 mm of manual measurement reliability for stature, head circumference and arm circumference. We found systematic bias when analyzing accuracy—on average 3D imaging overestimated stature and head circumference by 6 mm and 3 mm respectively, and underestimated arm circumference by 2 mm. The 3D imaging system used in this study is reliable, low-cost, portable, and can handle movement; making it ideal for use in routine nutritional assessment. However, additional research, particularly on accuracy, and further development of the scanning and processing software is needed before making policy and clinical practice recommendations on the routine use of 3D imaging for child anthropometry.

Metrics of early childhood growth in recent epidemiological research: A scoping review

Metrics to quantify child growth vary across studies of the developmental origins of health and disease. We conducted a scoping review of child growth studies in which length/height, weight or body mass index (BMI) was measured at ≥ 2 time points. From a 10% random sample of eligible studies published between Jan 2010-Jun 2016, and all eligible studies from Oct 2015-June 2016, we classified growth metrics based on author-assigned labels (e.g., 'weight gain') and a 'content signature', a numeric code that summarized the metric's conceptual and statistical properties. Heterogeneity was assessed by the number of unique content signatures, and label-to-content concordance. In 122 studies, we found 40 unique metrics of childhood growth. The most common approach to quantifying growth in length, weight or BMI was the calculation of each child's change in z-score. Label-to-content discordance was common due to distinct content signatures carrying the same label, and because of instances in which the same content signature was assigned multiple different labels. In conclusion, the numerous distinct growth metrics and the lack of specificity in the application of metric labels challenge the integration of data and inferences from studies investigating the determinants or consequences of variations in childhood growth.

Improving the quality of child anthropometry: Manual anthropometry in the Body Imaging for Nutritional Assessment Study (BINA)

Anthropometric data collected in clinics and surveys are often inaccurate and unreliable due to measurement error. The Body Imaging for Nutritional Assessment Study (BINA) evaluated the ability of 3D imaging to correctly measure stature, head circumference (HC) and arm circumference (MUAC) for children under five years of age. This paper describes the protocol for and the quality of manual anthropometric measurements in BINA, a study conducted in 2016–17 in Atlanta, USA. Quality was evaluated by examining digit preference, biological plausibility of z-scores, z-score standard deviations, and reliability. We calculated z-scores and analyzed plausibility based on the 2006 WHO Child Growth Standards (CGS). For reliability, we calculated intra- and inter-observer Technical Error of Measurement (TEM) and Intraclass Correlation Coefficient (ICC). We found low digit preference; 99.6% of z-scores were biologically plausible, with z-score standard deviations ranging from 0.92 to 1.07. Total TEM was 0.40 for stature, 0.28 for HC, and 0.25 for MUAC in centimeters. ICC ranged from 0.99 to 1.00. The quality of manual measurements in BINA was high and similar to that of the anthropometric data used to develop the WHO CGS. We attributed high quality to vigorous training, motivated and competent field staff, reduction of non-measurement error through the use of technology, and reduction of measurement error through adequate monitoring and supervision. Our anthropometry measurement protocol, which builds on and improves upon the protocol used for the WHO CGS, can be used to improve anthropometric data quality. The discussion illustrates the need to standardize anthropometric data quality assessment, and we conclude that BINA can provide a valuable evaluation of 3D imaging for child anthropometry because there is comparison to gold-standard, manual measurements.

Using a monitoring and evaluation framework to improve study efficiency and quality during a prospective cohort study in infants receiving rotavirus vaccination in El Alto, Bolivia: the Infant Nutrition, Inflammation, and Diarrheal Illness (NIDI) study

BACKGROUND

Implementing rigorous epidemiologic studies in low-resource settings involves challenges in participant recruitment and follow-up (e.g., mobile populations, distrust), biological sample collection (e.g., cold-chain, laboratory equipment scarcity) and data collection (e.g., literacy, staff training, and infrastructure). This article describes the use of a monitoring and evaluation (M&E) framework to improve study efficiency and quality during participant engagement, and biological sample and data collection in a longitudinal cohort study of Bolivian infants.

METHODS

The study occurred between 2013 and 2015 in El Alto, Bolivia, a high-altitude, urban, low-resource community. The study's M&E framework included indicators for participant engagement (e.g., recruitment, retention, safety), biological sample (e.g., stool and blood), and data (e.g., anthropometry, questionnaires) collection and quality. Monitoring indicators were measured regularly throughout the study and used for course correction, communication, and staff retraining.

RESULTS

Participant engagement indicators suggested that enrollment objectives were met (461 infants), but 15% loss-to-follow-up resulted in only 364 infants completing the study. Over the course of the study, there were four study-related adverse events (minor swelling and bruising related to a blood draw) and five severe adverse events (infant deaths) not related to study participation. Biological sample indicators demonstrated two blood samples collected from 95% (333 of 350 required) infants and stool collected for 61% of reported infant diarrhea episodes. Anthropometry data quality indicators were extremely high (median SDs for weight-for-length, length-for-age and weight-for-age z-scores 1.01, 0.98, and 1.03, respectively), likely due to extensive training, standardization, and monitoring efforts.

CONCLUSIONS

Conducting human subjects research studies in low-resource settings often presents unique logistical difficulties, and collecting high-quality data is often a challenge. Investing in comprehensive M&E is important to improve participant recruitment, retention and safety, and sample and data quality. The M&E framework from this study can be applied to other longitudinal studies.