Estimates and trends of zero vegetable or fruit consumption among children aged 6-23 months in 64 countries

Children require a diverse diet, that includes vegetables and fruits, to support growth and development and prevent non-communicable diseases. The WHO-UNICEF established a new infant and young child feeding (IYCF) indicator: zero vegetable or fruit (ZVF) consumption among children aged 6-23 months. We estimated the prevalence, trends, and factors associated with ZVF consumption using nationally representative, cross-sectional data on child health and nutrition in low-and-middle-income countries. We examined 125 Demographic and Health Surveys in 64 countries conducted between 2006-2020 with data on whether a child ate vegetables or fruits the previous day. Prevalence of ZVF consumption was calculated by country, region, and globally. Country trends were estimated and tested for statistical significance (p<0.05). Logistic regression analysis was used to examine the relationship between ZVF and child, mother, household, and survey cluster characteristics by world region and globally. Using a pooled estimate of the most recent survey available in each country, we estimate the global prevalence of ZVF consumption as 45.7%, with the highest prevalence in West and Central Africa (56.1%) and the lowest in Latin America and the Caribbean (34.5%). Recent trends in ZVF consumption varied by country (16 decreasing, eight increasing, 14 no change). Country trends in ZVF consumption represented diverse patterns of food consumption over time and may be affected by the timing of surveys. Children from wealthier households and children of mothers who are employed, more educated, and have access to media were less likely to consume ZVF. We find the prevalence of children aged 6-23 months who do not consume any vegetables or fruits is high and is associated with wealth and characteristics of the mother. Areas for future research include generating evidence from low-and-middle-income countries on effective interventions and translating strategies from other contexts to improve vegetable and fruit consumption among young children.

Associations between type of blood collection, analytical approach, mean haemoglobin and anaemia prevalence in population-based surveys: A systematic review and meta-analysis

Background

Previous studies have observed that haemoglobin concentrations can be affected by type of blood collection, analysis methods and device, and that near-in-time population-based surveys report substantially different anaemia prevalence. We investigated whether differences in mean haemoglobin or prevalence of anaemia between near-in-time surveys of the same population were associated with differences in type of blood collection or analytic approach to haemoglobin measurement.

Methods

We systematically identified pairs of population-based surveys that measured haemoglobin in the same population of women of reproductive age (WRA) or preschool-aged children (PSC). Surveys were matched on geographic coverage, urban/rural place of residence, inclusion of pregnant women, time of data collection (within 18 months), and, to the extent feasible, age range. Differences in anaemia prevalence were presented graphically. Random-effects meta-analysis and meta-regression of difference in mean haemoglobin were carried out, with subgroups defined by comparison of type of blood collection and analytic approach within each survey pair.

Results

We included 23 survey pairs from 17 countries for PSC and 17 survey pairs from 11 countries for WRA. Meta-regression indicates that surveys measuring haemoglobin with HemoCue® Hb 301 found higher haemoglobin concentrations than near-in-time surveys using HemoCue® Hb 201+ in non-pregnant women ((NPW); 5.8 g/L (95% confidence interval (CI) = 3.2-8.3) mean difference, n = 5 pairs) and PSC (4.3 g/L (1.4-7.2), n = 6). Surveys collecting venous blood found higher haemoglobin concentrations than near-in-time surveys collecting capillary blood in PSC (3.8 g/L (0.8-6.7), n = 8), but not NPW (0.4 g/L (-1.9-2.8), n = 9).

Conclusions

Because this study is observational, differences in haemoglobin concentrations in near-in-time surveys may be caused by other factors associated with choice of analytic approach or type of blood collected. The source or sources of differences should be clarified to improve use of surveys to prioritize and evaluate public health programs.

Registration

PROSPERO CRD42022296553.

Towards standardised and valid anthropometric indicators of nutritional status in middle childhood and adolescence

Recognition of the importance of nutrition during middle childhood (age 5-9 years) and adolescence (age 10-19 years) is increasing, particularly in the context of global food insecurity and rising overweight and obesity rates. Until now, policy makers have been slow to respond to rapidly changing patterns of malnutrition across these age groups. One barrier has been a scarcity of consistent and regular nutrition surveillance systems for these age groups. What should be measured, and how best to operationalise anthropometric indicators that have been the cornerstone of nutrition surveillance in younger children and in adults, has been the topic of ongoing debate. Even with consensus on the importance of a given anthropometric indicator, difficulties arise in interpreting trends over time and between countries owing to the use of different terminologies, reference data, and cutoff points. In this Viewpoint we highlight the need to revisit anthropometric indicators across middle childhood and adolescence, a process that will require WHO and UNICEF coordination, the engagement of national implementors and policy makers, and partnership with research communities and donors.

National, regional, and global estimates of anaemia by severity in women and children for 2000-19: a pooled analysis of population-representative data

BACKGROUND

Anaemia causes health and economic harms. The prevalence of anaemia in women aged 15-49 years, by pregnancy status, is indicator 2.2.3 of the UN Sustainable Development Goals, and the aim of halving the anaemia prevalence in women of reproductive age by 2030 is an extension of the 2025 global nutrition targets endorsed by the World Health Assembly (WHA). We aimed to estimate the prevalence of anaemia by severity for children aged 6-59 months, non-pregnant women aged 15-49 years, and pregnant women aged 15-49 years in 197 countries and territories and globally for the period 2000-19.

METHODS

For this pooled analysis of population-representative data, we collated 489 data sources on haemoglobin distribution in children and women from 133 countries, including 4·5 million haemoglobin measurements. Our data sources comprised health examination, nutrition, and household surveys, accessed as anonymised individual records or as summary statistics such as mean haemoglobin and anaemia prevalence. We used a Bayesian hierarchical mixture model to estimate haemoglobin distributions in each population and country-year. This model allowed for coherent estimation of mean haemoglobin and prevalence of anaemia by severity.

FINDINGS

Globally, in 2019, 40% (95% uncertainty interval [UI] 36-44) of children aged 6-59 months were anaemic, compared to 48% (45-51) in 2000. Globally, the prevalence of anaemia in non-pregnant women aged 15-49 years changed little between 2000 and 2019, from 31% (95% UI 28-34) to 30% (27-33), while in pregnant women aged 15-49 years it decreased from 41% (39-43) to 36% (34-39). In 2019, the prevalence of anaemia in children aged 6-59 months exceeded 70% in 11 countries and exceeded 50% in all women aged 15-49 years in ten countries. Globally in all populations and in most countries and regions, the prevalence of mild anaemia changed little, while moderate and severe anaemia declined in most populations and geographical locations, indicating a shift towards mild anaemia.

INTERPRETATION

Globally, regionally, and in nearly all countries, progress on anaemia in women aged 15-49 years is insufficient to meet the WHA global nutrition target to halve anaemia prevalence by 2030, and the prevalence of anaemia in children also remains high. A better understanding of the context-specific causes of anaemia and quality implementation of effective multisectoral actions to address these causes are needed.

FUNDING

USAID, US Centers for Disease Control and Prevention, and Bill & Melinda Gates Foundation.

Comparing costs and cost-efficiency of platforms for micronutrient powder (MNP) delivery to children in rural Uganda

Micronutrient powder (MNP) can reduce iron deficiency in young children, which has been well established in efficacy trials. However, the cost of different delivery platforms has not been determined. We calculated the cost and cost-efficiency of distributed MNP through community-based mechanisms and in health facilities in a primarily rural district in Uganda. An endline survey (n = 1072) identified reach and adherence. During the 9-month pilot, 37,458 (community platform) and 12,390 (facility platform) packets of MNP were distributed. Each packet consisted of 30 MNP sachets. In 2016, total costs were $277,082 (community platform, $0.24/sachet) and $221,568 (facility platform, $0.59/sachet). The cost per child reached was lower in the community platform ($53.24) than the facility platform ($65.97). The cost per child adhering to a protocol was $58.08 (community platform) and $72.69 (facility platform). The estimated cost of scaling up the community platform pilot to the district level over 3 years to cover approximately 17,890 children was $1.23 million (scale-up integrated into a partner agency program) to $1.62 million (government scale-up scenario). Unlike previous estimates, these included opportunity costs. Community-based MNP delivery costs were greater, yet more cost-efficient per child reached and adhering to protocol than facility-based delivery. However, total costs for untargeted MNP delivery under program settings are potentially prohibitive.

The Impact of Nutrition-Specific and Nutrition-Sensitive Interventions on Hemoglobin Concentrations and Anemia: A Meta-review of Systematic Reviews

Anemia is a multifactorial condition arising from inadequate nutrition, infection, chronic disease, and genetic-related etiologies. Our aim was to assess the impact of nutrition-sensitive and nutrition-specific interventions on hemoglobin (Hb) concentrations and anemia to inform the prioritization and scale-up of interventions to address the multiple causes of anemia. We performed a meta-review synthesis of information by searching multiple databases for reviews published between 1990 and 2017 and used standard methods for conducting a meta-review of reviews, including double independent screening, extraction, and quality assessment. Quantitative pooling and narrative syntheses were used to summarize information. Hb concentration and anemia outcomes were pooled in specific population groups (children aged <5 y, school-age children, and pregnant women). Methodological quality of the systematic reviews was assessed using Assessing the Methodological Quality of Systematic Reviews (AMSTAR) criteria. Of the 15,444 records screened, we identified 118 systematic reviews that met inclusion criteria. Reviews focused on nutrition-specific interventions (96%). Daily and intermittent iron supplementation, micronutrient powders, malaria treatment, use of insecticide-treated nets (ITNs), and delayed cord clamping were associated with increased Hb concentration in children aged <5 y. Among children older than 5 y, daily and intermittent iron supplementation and deworming, and in pregnant women, daily iron-folic acid supplementation, use of ITNs, and delayed cord clamping, were associated with increased Hb concentration. Similar results were obtained for the reduced risk of anemia outcome. This meta-review suggests the importance of nutrition-specific interventions for anemia and highlights the lack of evidence to understand the influence of nutrition-sensitive and multifaceted interventions on the condition.

Anthropometric data quality assessment in multisurvey studies of child growth

BACKGROUND

Population-based surveys collect crucial data on anthropometric measures to track trends in stunting [height-for-age z score (HAZ) < -2SD] and wasting [weight-for-height z score (WHZ) < -2SD] prevalence among young children globally. However, the quality of the anthropometric data varies between surveys, which may affect population-based estimates of malnutrition.

OBJECTIVES

We aimed to develop composite indices of anthropometric data quality for use in multisurvey analysis of child health and nutritional status.

METHODS

We used anthropometric data for children 0-59 mo of age from all publicly available Demographic and Health Surveys (DHS) from 2000 onwards. We derived 6 indicators of anthropometric data quality at the survey level, including 1) date of birth completeness, 2) anthropometric measure completeness, 3) digit preference for height and age, 4) difference in mean HAZ by month of birth, 5) proportion of biologically implausible values, and 6) dispersion of HAZ and WHZ distribution. Principal component factor analysis was used to generate a composite index of anthropometric data quality for HAZ and WHZ separately. Surveys were ranked from the highest (best) to the lowest (worst) index values in anthropometric quality across countries and over time.

RESULTS

Of the 145 DHS included, the majority (83 of 145; 57%) were conducted in Sub-Saharan Africa. Surveys were ranked from highest to lowest anthropometric data quality relative to other surveys using the composite index for HAZ. Although slightly higher values in recent DHS suggest potential improvements in anthropometric data quality over time, there continues to be substantial heterogeneity in the quality of anthropometric data across surveys. Results were similar for the WHZ data quality index.

CONCLUSIONS

A composite index of anthropometric data quality using a parsimonious set of individual indicators can effectively discriminate among surveys with excellent and poor data quality. Such indices can be used to account for variations in anthropometric data quality in multisurvey epidemiologic analyses of child health.

Alternative Metrics of Linear Growth for Tracking Global Progress in Child Undernutrition (P10-001-19)

Objectives

Compare under-5y stunting prevalence to alternative height-for-age z-score (HAZ)-based measures of location (MoLs) in terms of the strength of their relationship with key population-level indicators known to be associated with HAZ; and, examine the modification of these associations by anthropometric data quality.

Methods

Data from 140 Demographic and Health Surveys (DHS) from 63 low- and middle-income countries (LMICs) (2000 to present) were used to assess pairwise associations between seven alternative HAZ-based MoLs and three population-level indicators, using absolute values of correlation coefficients (corr) and Akaike's Information Criterion (AIC) from linear mixed effects models. Extended models with interaction terms were used to assess how survey quality (defined using a score based on principal component analysis) modified each HAZ MoL - population-level indicator relationship. All analyses were performed under three flagging approaches for excluding HAZ outliers: WHO (cut-off at -6/ + 6 SD of the reference mean); SMART (cut-off at -3/ + 3 SD of the observed mean); and no flagging.

Results

All HAZ MoLs were highly correlated with stunting (range: 0.92 to 0.98). Correlations between HAZ MoLs and population-level indicators were moderate and similar across metrics (range: 0.44 to 0.65). Stunting and model-predicted HAZ at 3y frequently had among the highest corr and lowest AIC values. Extended models consistently showed that associations between HAZ MoLs and population-level indicators attenuate as survey quality decreases. This modifying effect was weakest for stunting and predicted HAZ at 3y across flagging scenarios, and under conditions of WHO flagging across most MoLs.

Conclusions

Preliminary analyses suggest that stunting is at least as or more robust compared to most other HAZ-based MoLs based on the strength of its correlation with population-level indicators, and insensitivity of those associations to variations in survey quality. Of the MoLs that represent central tendency, predicted HAZ at 3y performed comparably to stunting, and may have conceptual advantages for comparing child undernutrition within and across LMICs.

Funding Sources

SickKids Hospital Growth and Development Fellowship Program. United States Agency for International Development (USAID) through the DHS Program.

Supporting Tables, Images and/or Graphs

Measurement and interpretation of hemoglobin concentration in clinical and field settings: a narrative review

Anemia affects over 800 million women and children globally. Defined as a limited or insufficient functional red blood cell supply in peripheral blood, anemia causes a reduced oxygen supply to tissues and can have serious health consequences for women and children. Hemoglobin (Hb) concentration is most commonly measured for anemia diagnosis. Methods to measure Hb are usually invasive (requiring a blood sample); however, advances in diagnostic and clinical chemistry over the past decade have led to the development of new noninvasive methods. Accurate diagnosis at the individual level is important to identify individuals who require treatment. At the population level, anemia prevalence estimates are often the impetus for national nutrition policies or programs. Thus, it is essential that methods for Hb measurement are sensitive, specific, accurate, and reproducible. The objective of our narrative review is to describe the basic principles, advantages, limitations, and quality control issues related to methods of Hb measurement in clinical and field settings. We also discuss other biomarkers and tests that can help to determine the severity and underlying causes of anemia. In conclusion, there are many established and emerging methods to measure Hb concentration, each with their own advantages, limitations, and factors to consider before use.

Monitoring and surveillance for multiple micronutrient supplements in pregnancy

The World Health Organization (WHO) recommends iron–folic acid (IFA) supplementation during pregnancy to improve maternal and infant health outcomes. Multiple micronutrient (MMN) supplementation in pregnancy has been implemented in select countries and emerging evidence suggests that MMN supplementation in pregnancy may provide additional benefits compared to IFA alone. In 2015, WHO, the United Nations Children's Fund (UNICEF), and the Micronutrient Initiative held a “Technical Consultation on MMN supplements in pregnancy: implementation considerations for successful incorporation into existing programmemes,” which included a call for indicators needed for monitoring, evaluation, and surveillance of MMN supplementation programmes. Currently, global surveillance and monitoring data show that overall IFA supplementation programmes suffer from low coverage and intake adherence, despite inclusion in national policies. Common barriers that limit the effectiveness of IFA—which also apply to MMN programmes—include weak supply chains, low access to antenatal care services, low‐quality behaviour change interventions to support and motivate women, and weak or non‐existent monitoring systems used for programme improvement. The causes of these barriers in a given country need careful review to resolve them. As countries heighten their focus on supplementation during pregnancy, or if they decide to initiate or transition into MMN supplementation, a priority is to identify key monitoring indicators to address these issues and support effective programmes. National and global monitoring and surveillance data on IFA supplementation during pregnancy are primarily derived from cross‐sectional surveys and, on a more routine basis, through health and logistics management information systems. Indicators for IFA supplementation exist; however, the new indicators for MMN supplementation need to be incorporated. We reviewed practice‐based evidence, guided by the WHO/Centers for Disease Control and Prevention logic model for vitamin and mineral interventions in public health programmes, and used existing manuals, published literature, country reports, and the opinion of experts, to identify monitoring, evaluation, and surveillance indicators for MMN supplementation programmes. We also considered cross‐cutting indicators that could be used across programme settings, as well as those specific to common delivery models, such as antenatal care services. We then described mechanisms for collecting these data, including integration within existing government monitoring systems, as well as other existing or proposed systems. Monitoring data needs at all stages of the programme lifecycle were considered, as well as the feasibility and cost of data collection. We also propose revisions to global‐, national‐, and subnational‐surveillance indicators based on these reviews.