National, regional, and global estimates of low birthweight in 2020, with trends from 2000: a systematic analysis.

BACKGROUND: Low birthweight (LBW; <2500 g) is an important predictor of health outcomes throughout the life course. We aimed to update country, regional, and global estimates of LBW prevalence for 2020, with trends from 2000, to assess progress towards global targets to reduce LBW by 30% by 2030. METHODS: For this systematic analysis, we searched population-based, nationally representative data on LBW from Jan 1, 2000, to Dec 31, 2020. Using 2042 administrative and survey datapoints from 158 countries and areas, we developed a Bayesian hierarchical regression model incorporating country-specific intercepts, time-varying covariates, non-linear time trends, and bias adjustments based on data quality. We also provided novel estimates by birthweight subgroups. FINDINGS: An estimated 19·8 million (95% credible interval 18·4-21·7 million) or 14·7% (13·7-16·1) of liveborn newborns were LBW worldwide in 2020, compared with 22·1 million (20·7-23·9 million) and 16·6% (15·5-17·9) in 2000-an absolute reduction of 1·9 percentage points between 2000 and 2020. Using 2012 as the baseline, as this is when the Global Nutrition Target began, the estimated average annual rate of reduction from 2012 to 2020 was 0·3% worldwide, 0·85% in southern Asia, and 0·59% in sub-Saharan Africa. Nearly three-quarters of LBW births in 2020 occurred in these two regions: of 19 833 900 estimated LBW births worldwide, 8 817 000 (44·5%) were in southern Asia and 5 381 300 (27·1%) were in sub-Saharan Africa. Of 945 300 estimated LBW births in northern America, Australia and New Zealand, central Asia, and Europe, approximately 35·0% (323 700) weighed less than 2000 g: 5·8% (95% CI 5·2-6·4; 54 800 [95% CI 49 400-60 800]) weighed less than 1000 g, 9·0% (8·7-9·4; 85 400 [82 000-88 900]) weighed between 1000 g and 1499 g, and 19·4% (19·0-19·8; 183 500 [180 000-187 000]) weighed between 1500 g and 1999 g. INTERPRETATION: Insufficient progress has occurred over the past two decades to meet the Global Nutrition Target of a 30% reduction in LBW between 2012 and 2030. Accelerating progress requires investments throughout the lifecycle focused on primary prevention, especially for adolescent girls and women living in the most affected countries. With increasing numbers of births in facilities and advancing electronic information systems, improvements in the quality and availability of administrative LBW data are also achievable. FUNDING: The Children's Investment Fund Foundation; the UNDP-UNFPA-UNICEF-WHO World Bank Special Programme of Research, Development and Research Training in Human Reproduction; and the Bill & Melinda Gates Foundation.

Small babies, big risks: global estimates of prevalence and mortality for vulnerable newborns to accelerate change and improve counting.

Small newborns are vulnerable to mortality and lifelong loss of human capital. Measures of vulnerability previously focused on liveborn low-birthweight (LBW) babies, yet LBW reduction targets are off-track. There are two pathways to LBW, preterm birth and fetal growth restriction (FGR), with the FGR pathway resulting in the baby being small for gestational age (SGA). Data on LBW babies are available from 158 (81%) of 194 WHO member states and the occupied Palestinian territory, including east Jerusalem, with 113 (58%) having national administrative data, whereas data on preterm births are available from 103 (53%) of 195 countries and areas, with only 64 (33%) providing national administrative data. National administrative data on SGA are available for only eight countries. Global estimates for 2020 suggest 13·4 million livebirths were preterm, with rates over the past decade remaining static, and 23·4 million were SGA. In this Series paper, we estimated prevalence in 2020 for three mutually exclusive types of small vulnerable newborns (SVNs; preterm non-SGA, term SGA, and preterm SGA) using individual-level data (2010-20) from 23 national datasets (∼110 million livebirths) and 31 studies in 18 countries (∼0·4 million livebirths). We found 11·9 million (50% credible interval [Crl] 9·1-12·2 million; 8·8%, 50% Crl 6·8-9·0%) of global livebirths were preterm non-SGA, 21·9 million (50% Crl 20·1-25·5 million; 16·3%, 14·9-18·9%) were term SGA, and 1·5 million (50% Crl 1·2-4·2 million; 1·1%, 50% Crl 0·9-3·1%) were preterm SGA. Over half (55·3%) of the 2·4 million neonatal deaths worldwide in 2020 were attributed to one of the SVN types, of which 73·4% were preterm and the remainder were term SGA. Analyses from 12 of the 23 countries with national data (0·6 million stillbirths at ≥22 weeks gestation) showed around 74% of stillbirths were preterm, including 16·0% preterm SGA and approximately one-fifth of term stillbirths were SGA. There are an estimated 1·9 million stillbirths per year associated with similar vulnerability pathways; hence integrating stillbirths to burden assessments and relevant indicators is crucial. Data can be improved by counting, weighing, and assessing the gestational age of every newborn, whether liveborn or stillborn, and classifying small newborns by the three vulnerability types. The use of these more specific types could accelerate prevention and help target care for the most vulnerable babies.

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.

Development, Validity, and Cross-Context Equivalence of the Child Food Insecurity Experiences Scale for Assessing Food Insecurity of School-Age Children and Adolescents.

BACKGROUND: Children ages 6 to 17 years can accurately assess their own food insecurity, whereas parents are inaccurate reporters of their children's experiences of food insecurity. No globally applicable scale to assess the food insecurity of children has been developed and validated. OBJECTIVES: We aimed to develop a globally applicable, experience-based measure of child and adolescent food insecurity and establish the validity and cross-contextual equivalence of the measure. METHODS: The 10-item Child Food Insecurity Experiences Scale (CFIES) was based on items previously validated from questionnaires from the United States, Venezuela, and Lebanon. Cognitive interviews were conducted to check understanding of the items. The questionnaire then was administered in 15 surveys in 13 countries. Other items in each survey that assessed the household socioeconomic status, household food security, or child psychological functioning were selected as criterion variables to compare to the scores from the CFIES. To investigate accuracy (i.e., criterion validity), linear regression estimated the associations of the CFIES scores with the criterion variables. To investigate the cross-contextual equivalence (i.e., measurement invariance), the alignment method was used based on classical measurement theory. RESULTS: Across the 15 surveys, the mean scale scores for the CFIES ranged from 1.65 to 5.86 (possible range of 0 to 20) and the Cronbach alpha ranged from 0.88 to 0.94. The variance explained by a 1-factor model ranged from 0.92 to 0.99. Accuracy was demonstrated by expected associations with criterion variables. The percentages of equivalent thresholds and loadings across the 15 surveys were 28.0 and 5.33, respectively, for a total percentage of nonequivalent thresholds and loadings of 16.7, well below the guideline of <25%. That is, 83.3% of thresholds and loadings were equivalent across these surveys. CONCLUSIONS: The CFIES provides a globally applicable, valid, and cross-contextually equivalent measure of the experiences of food insecurity of school-aged children and adolescents, as reported by them.

Estimating Childhood Stunting and Overweight Trends in the European Region from Sparse Longitudinal Data.

BACKGROUND: Monitoring countries' progress toward the achievement of their nutrition targets is an important task, but data sparsity makes monitoring trends challenging. Childhood stunting and overweight data in the European region over the last 30 y have had low coverage and frequency, with most data only covering a portion of the complete age interval of 0-59 mo. OBJECTIVES: We implemented a statistical method to extract useful information on child malnutrition trends from sparse longitudinal data for these indicators. METHODS: Heteroscedastic penalized longitudinal mixed models were used to accommodate data sparsity and predict region-wide, country-level trends over time. We leveraged prevalence estimates stratified by sex and partial age intervals (i.e., intervals that do not cover the complete 0-59 mo), which expanded the available data (for stunting: from 84 sources and 428 prevalence estimates to 99 sources and 1786 estimates), improving the robustness of our analysis. RESULTS: Results indicated a generally decreasing trend in stunting and a stable, slightly diminishing rate for overweight, with large differences in trends between low- and middle-income countries compared with high-income countries. No differences were found between age groups and between sexes. Cross-validation results indicated that both stunting and overweight models were robust in estimating the indicators for our data (root mean squared error: 0.061 and 0.056; median absolute deviation: 0.045 and 0.042; for stunting and overweight, respectively). CONCLUSIONS: These statistical methods can provide useful and robust information on child malnutrition trends over time, even when data are sparse.

Study protocol for UNICEF and WHO estimates of global, regional, and national low birthweight prevalence for 2000 to 2020.

Background Reducing low birthweight (LBW, weight at birth less than 2,500g) prevalence by at least 30% between 2012 and 2025 is a target endorsed by the World Health Assembly that can contribute to achieving Sustainable Development Goal 2 (Zero Hunger) by 2030. The 2019 LBW estimates indicated a global prevalence of 14.6% (20.5 million newborns) in 2015. We aim to develop updated LBW estimates at global, regional, and national levels for up to 202 countries for the period of 2000 to 2020. Methods Two types of sources for LBW data will be sought: national administrative data and population-based surveys. Administrative data will be searched for countries with a facility birth rate ≥80% and included when birthweight data account for ≥80% of UN estimated live births for that country and year. Surveys with birthweight data published since release of the 2019 edition of the LBW estimates will be adjusted using the standard methodology applied for the previous estimates. Risk of bias assessments will be undertaken. Covariates will be selected based on a conceptual framework of plausible associations with LBW, covariate time-series data quality, collinearity between covariates and correlations with LBW. National LBW prevalence will be estimated using a Bayesian multilevel-mixed regression model, then aggregated to derive regional and global estimates through population-weighted averages. Conclusion Whilst availability of LBW data has increased, especially with more facility births, gaps remain in the quantity and quality of data, particularly in low-and middle-income countries. Challenges include high percentages of missing data, lack of adherence to reporting standards, inaccurate measurement, and data heaping. Updated LBW estimates are important to highlight the global burden of LBW, track progress towards nutrition targets, and inform investments in programmes. Reliable, nationally representative data are key, alongside investments to improve the measurement and recording of an accurate birthweight for every baby.

Improving estimates of the burden of severe wasting: analysis of secondary prevalence and incidence data from 352 sites.

INTRODUCTION: Estimates of incident cases of severe wasting among young children are not available for most settings but are needed for optimal planning of treatment programmes and burden estimation. To improve programme planning, global guidance recommends a single 'incidence correction factor' of 1.6 be applied to available prevalence estimates to account for incident cases. This study aimed to update estimates of the incidence correction factor to improve programme planning and inform the approach to burden estimation for severe wasting. METHODS: A global call was issued for secondary data from severe wasting treatment programmes including prevalence, population size, programme admission and programme coverage through a UNICEF-led effort. Site-specific incidence correction factors were calculated as the number of incident cases (annual programme admissions/programme coverage) divided by the number of prevalent cases (prevalence*population size). Estimates were aggregated by country, region and overall using inverse-variance weighted random-effects meta-analysis. RESULTS: We estimated incidence correction factors from 352 sites in 20 countries. Estimates aggregated by country ranged from 1.3 (Nigeria) to 30.1 (Burundi). Excluding implausible values, the overall incidence correction factor was 3.6 (95% CI 3.4 to 3.9). CONCLUSION: Our results suggest that incidence correction factors vary between sites and that the burden of severe wasting will often be underestimated using the currently recommended incidence correction factor of 1.6. Application of updated incidence correction factors represents a simple way to improve programme planning when incidence data are not available and could inform the approach to burden estimation.

Measuring coverage of infant and young child feeding counselling interventions: A framework and empirical considerations for survey question design.

Most countries implement nutrition counselling interventions as part of programmes to support breastfeeding and complementary feeding. However, data to track coverage of counselling interventions are rarely available. As a result, little is known about the coverage of counselling on infant and young child feeding (IYCF). Survey-based data collection systems generally collect data on IYCF practices but do not collect data on coverage of interventions to support IYCF, and those surveys that do collect this information do not do so consistently. We present a framework to guide the design of survey questions to measure IYCF counselling coverage. We provide examples of how large-scale surveys for programme evaluation and national monitoring have included survey questions to address these data gaps. Our review suggests that elements relevant to designing survey questions to capture coverage of counselling interventions include timing of contact, target behaviour and message content, place of contact, type of service provider, frequency of contact and mode of intervention. Application of this framework may help strengthen harmonized measurement of IYCF counselling coverage to enable better tracking of programme investments, document progress in scaling up nutrition services and allow for cross-country comparisons. Thus, improving measurement of counselling coverage may lead to improved reach of programmes to support optimal IYCF practices.

Measuring the coverage of nutrition interventions along the continuum of care: time to act at scale.

The global community is committed to addressing malnutrition. And yet, coverage data for high-impact interventions along the continuum of care remain scarce due to several measurement and data collection challenges. In this analysis paper, we identify 24 nutrition interventions that should be tracked by all countries, and determine if their coverage is currently measured by major household nutrition and health surveys. We then present three case studies, using published literature and empirical data from large-scale initiatives, to illustrate the kind of data collection innovations that are feasible. We find that data are not routinely collected in a standardised way across countries for most of the core set of interventions. Case studies-of growth monitoring and screening for acute malnutrition, infant and young child feeding counselling, and nutrition monitoring in India-highlight both challenges and potential solutions. Advancing the nutrition intervention coverage measurement agenda is essential for sustained progress in driving down rates of malnutrition. It will require (1) global consensus on a core set of validated coverage indicators on proven, high-impact nutrition-specific interventions; (2) the inclusion of coverage measurement and indicator guidance in WHO intervention recommendations; (3) the incorporation of these indicators into data collection mechanisms and relevant intervention delivery platforms; and (4) an agenda for continuous measurement improvement.

Advances in the measurement of coverage for RMNCH and nutrition: from contact to effective coverage.

Current methods for measuring intervention coverage for reproductive, maternal, newborn, and child health and nutrition (RMNCH+N) do not adequately capture the quality of services delivered. Without information on the quality of care, it is difficult to assess whether services provided will result in expected health improvements. We propose a six-step coverage framework, starting from a target population to (1) service contact, (2) likelihood of services, (3) crude coverage, (4) quality-adjusted coverage, (5) user-adherence-adjusted coverage and (6) outcome-adjusted coverage. We support our framework with a comprehensive review of published literature on effective coverage for RMNCH+N interventions since 2000. We screened 8103 articles and selected 36 from which we summarised current methods for measuring effective coverage and computed the gaps between 'crude' coverage measures and quality-adjusted measures. Our review showed considerable variability in data sources, indicator definitions and analytical approaches for effective coverage measurement. Large gaps between crude coverage and quality-adjusted coverage levels were evident, ranging from an average of 10 to 38 percentage points across the RMNCH+N interventions assessed. We define effective coverage as the proportion of individuals experiencing health gains from a service among those who need the service, and distinguish this from other indicators along a coverage cascade that make quality adjustments. We propose a systematic approach for analysis along six steps in the cascade. Research to date shows substantial drops in effective delivery of care across these steps, but variation in methods limits comparability of the results. Advancement in coverage measurement will require standardisation of effective coverage terminology and improvements in data collection and methodological approaches.

National, regional, and worldwide estimates of low birthweight in 2015, with trends from 2000: a systematic analysis.

BACKGROUND: Low birthweight (LBW) of less than 2500 g is an important marker of maternal and fetal health, predicting mortality, stunting, and adult-onset chronic conditions. Global nutrition targets set at the World Health Assembly in 2012 include an ambitious 30% reduction in LBW prevalence between 2012 and 2025. Estimates to track progress towards this target are lacking; with this analysis, we aim to assist in setting a baseline against which to assess progress towards the achievement of the World Health Assembly targets. METHODS: We sought to identify all available LBW input data for livebirths for the years 2000-16. We considered population-based national or nationally representative datasets for inclusion if they contained information on birthweight or LBW prevalence for livebirths. A new method for survey adjustment was developed and used. For 57 countries with higher quality time-series data, we smoothed country-reported trends in birthweight data by use of B-spline regression. For all other countries, we estimated LBW prevalence and trends by use of a restricted maximum likelihood approach with country-level random effects. Uncertainty ranges were obtained through bootstrapping. Results were summed at the regional and worldwide level. FINDINGS: We collated 1447 country-years of birthweight data (281 million births) for 148 countries of 195 UN member states (47 countries had no data meeting inclusion criteria). The estimated worldwide LBW prevalence in 2015 was 14·6% (uncertainty range [UR] 12·4-17·1) compared with 17·5% (14·1-21·3) in 2000 (average annual reduction rate [AARR] 1·23%). In 2015, an estimated 20·5 million (UR 17·4-24·0 million) livebirths were LBW, 91% from low-and-middle income countries, mainly southern Asia (48%) and sub-Saharan Africa (24%). INTERPRETATION: Although these estimates suggest some progress in reducing LBW between 2000 and 2015, achieving the 2·74% AARR required between 2012 and 2025 to meet the global nutrition target will require more than doubling progress, involving both improved measurement and programme investments to address the causes of LBW throughout the lifecycle. FUNDING: Bill & Melinda Gates Foundation, The Children's Investment Fund Foundation, United Nations Children's Fund (UNICEF), and WHO.

Prevalence thresholds for wasting, overweight and stunting in children under 5 years.

OBJECTIVE: Prevalence ranges to classify levels of wasting and stunting have been used since the 1990s for global monitoring of malnutrition. Recent developments prompted a re-examination of existing ranges and development of new ones for childhood overweight. The present paper reports from the WHO-UNICEF Technical Expert Advisory Group on Nutrition Monitoring. DESIGN: Thresholds were developed in relation to sd of the normative WHO Child Growth Standards. The international definition of 'normal' (2 sd below/above the WHO standards median) defines the first threshold, which includes 2·3 % of the area under the normalized distribution. Multipliers of this 'very low' level (rounded to 2·5 %) set the basis to establish subsequent thresholds. Country groupings using the thresholds were produced using the most recent set of national surveys. SETTING: One hundred and thirty-four countries. SUBJECTS: Children under 5 years. RESULTS: For wasting and overweight, thresholds are: 'very low' (≈6 times 2·5 %). For stunting, thresholds are: 'very low' (≈12 times 2·5 %). CONCLUSIONS: The proposed thresholds minimize changes and keep coherence across anthropometric indicators. They can be used for descriptive purposes to map countries according to severity levels; by donors and global actors to identify priority countries for action; and by governments to trigger action and target programmes aimed at achieving 'low' or 'very low' levels. Harmonized terminology will help avoid confusion and promote appropriate interventions.

Viral Hepatitis Strategic Information to Achieve Elimination by 2030: Key Elements for HIV Program Managers.

Evidence documenting the global burden of disease from viral hepatitis was essential for the World Health Assembly to endorse the first Global Health Sector Strategy (GHSS) on viral hepatitis in May 2016. The GHSS on viral hepatitis proposes to eliminate viral hepatitis as a public health threat by 2030. The GHSS on viral hepatitis is in line with targets for HIV infection and tuberculosis as part of the Sustainable Development Goals. As coordination between hepatitis and HIV programs aims to optimize the use of resources, guidance is also needed to align the strategic information components of the 2 programs. The World Health Organization monitoring and evaluation framework for viral hepatitis B and C follows an approach similar to the one of HIV, including components on the following: (1) context (prevalence of infection), (2) input, (3) output and outcome, including the cascade of prevention and treatment, and (4) impact (incidence and mortality). Data systems that are needed to inform this framework include (1) surveillance for acute hepatitis, chronic infections, and sequelae and (2) program data documenting prevention and treatment, which for the latter includes a database of patients. Overall, the commonalities between HIV and hepatitis at the strategic, policy, technical, and implementation levels justify coordination, strategic linkage, or integration, depending on the type of HIV and viral hepatitis epidemics. Strategic information is a critical area of this alignment under the principle of what gets measured gets done. It is facilitated because the monitoring and evaluation frameworks for HIV and viral hepatitis were constructed using a similar approach. However, for areas where elimination of viral hepatitis requires data that cannot be collected through the HIV program, collaborations are needed with immunization, communicable disease control, tuberculosis, and hepatology centers to ensure collection of information for the remaining indicators.

Monitoring Prevention Impact of Mother-to-Child Transmission of HIV in Concentrated Epidemics With Program and Survey Data.

BACKGROUND: The prevention of mother-to-child transmission (PMTCT) of HIV program was introduced in Vietnam in 2005. Despite the scaling up of PMTCT programs, the rate of mother-to-child HIV transmission in Vietnam was estimated as high as 20% in 2013. OBJECTIVE: The objective of this study was to assess the outcomes of PMTCT and identified factors associated with mother-to-child transmission and infant survival using survey and program data in a high HIV burden province in Vietnam. METHODS: This community-based retrospective cohort study observed pregnant women diagnosed with HIV infection in Thai Nguyen province from October 2008 to December 2012. Data were collected through interviews using a structured questionnaire and through reviews of log books and medical charts in antenatal care and HIV clinics. Logistic regression and survival analysis were used to analyze data using Stata (StataCorp). RESULTS: A total of 172 pregnant women living with HIV were identified between 2008 and 2012. Most of these women had acquired the HIV infection from their husband (77/119, 64.7%). Significant improvement in the PMTCT program was documented, including reduction in late diagnosis of HIV for pregnant women from 62.5% in 2008 to 30% in 2012. Access to antiretrovirals (ARVs) improved, increasing from a rate of 18.2% (2008) to 70.0% (2011) for mothers and from 36.4% (2008) to 93.3% (2012) for infants. For infants, early diagnosis within 2 months of birth reached 66.7% in 2012 compared with 16.7% in 2009. Transmission rate reduced from 27.3% in 2008 to 6.7% in 2012. Late diagnosis was associated with increased risk for HIV transmission (odds ratio [OR] 14.7, 95% CI 1.8-121.4, P=.01), whereas ARV therapy for mother and infant in combination with infant formula feeding were associated with reduced risk for HIV transmission (OR 0.01, 95% CI 0.001-0.1; P<.001). Overall survival rate for HIV-exposed infants at 12 months was 97.7%. CONCLUSIONS: A combination of program and survey data measured the impact of prevention of HIV transmission from mother-to-child interventions. Significant improvement in access to the interventions was documented in Thai Nguyen province. However, factors that increased the risk of HIV transmission, such as late diagnosis, remain to be addressed.

Elimination of mother-to-child transmission of HIV and Syphilis (EMTCT): Process, progress, and program integration.

Melanie Taylor and colleagues discuss progress towards eliminating vertical transmission of HIV and syphilis.

Monitoring HIV Treatment and the Health Sector Cascade: From Treatment Numbers to Impact.

Although not originally part of the MDGs, HIV treatment has been at the center of global HIV reporting since 2003, marked by achievement of the target of 15 million people receiving treatment before 2015 and 18.2 million (16.1-19.0 million) by mid 2016. Monitoring of treatment has been strengthened with harmonized partner reporting and accountability with regular, annual reports. Beyond treatment numbers, increasingly measures of treatment adherence, retention and outcomes have been reported though with varying quality and completeness. However, with the sustainable development goals (SDGs), monitoring treatment is changing in three important ways. First, treatment monitoring is shifting from numbers to coverage and gaps in a cascade of services to achieve universal access. Secondly, this requires greater emphasis on disaggregated, individual level patient and case monitoring systems, which can better support linkage, retention and chronic, long term care. Thirdly, the prevention, testing and treatment cascade with a clear results chain, links treatment numbers to impact, in terms of reduced viral load, mortality and incidence. This agenda will require a greater contribution of routine impact evaluation alongside monitoring, with treatment seen as part of a cascade of services to ensure impact on mortality and incidence. In conclusion, the shift from monitoring treatment numbers to treatment linked to universal access to prevention, testing and treatment and impact on mortality and incidence, will be critical to monitor, evaluate, and improve HIV programs as part of the SDGs.