Physiologically Based Trimester-Specific Serum Ferritin Thresholds for Iron Deficiency in US Pregnant Women.

Serum ferritin (SF) concentration is the most widely used indicator for iron deficiency (ID). During pregnancy, the World Health Organization recently recommended SF thresholds for ID of <15 µg/L for the 1st trimester of pregnancy, based on expert opinion, and made no recommendations for the 2nd and 3rd trimesters. We examined the relationship of SF with two independent indicators of the onset of iron-deficient erythropoiesis, hemoglobin (Hb) and soluble transferrin receptor 1 (sTfR1), in cross-sectional data from NHANES for 1999-2010 and 2015-2018. We included 1288 pregnant women 15-49 years and excluded women with inflammation or potential liver disease. We used restricted cubic spline (RCS) regression analysis to determine SF thresholds for iron-deficient erythropoiesis. SF decreased during pregnancy; geometric mean SF was higher during the 1st and lower during the 2nd and 3rd trimesters. Using RCS analysis, the SF thresholds identified during pregnancy were <25.8 (18.1, 28.5) µg/L during 1st trimester, <18.3 (16.3, 22.9) µg/L during 2nd trimester, and <19.0 (14.4, 26.1) µg/L during 3rd trimester. These SF threshold levels track concentrations of hepcidin, the iron regulatory hormone controlling the mobilization of iron stores. A SF concentration of <15 µg/L as the criterion for ID may underestimate the true prevalence of ID throughout pregnancy. In our study, an additional one of every ten pregnant women would be recognized as iron deficient by using the physiologically based thresholds at SF of about 25 µg/L during the 1st and of about 20 µg/L during the 2nd and 3rd trimesters.

Comparison of Current World Health Organization Guidelines with Physiologically Based Serum Ferritin Thresholds for Iron Deficiency in Healthy Young Children and Nonpregnant Women Using Data from the Third National Health and Nutrition Examination Survey.

BACKGROUND: Current WHO serum ferritin (SF) thresholds for iron deficiency (ID) in children (<12 µg/L) and women (<15 µg/L) are derived from expert opinion based on radiometric assays in use decades ago. Using a contemporary immunoturbidimetry assay, higher thresholds (children, <20 µg/L; women, <25 µg/L) were identified from physiologically based analyses. OBJECTIVE: We examined relationships of SF measured using an immunoradiometric assay from the era of expert opinion with 2 independently measured indicators of ID, hemoglobin (Hb) and erythrocyte zinc protoporphyrin (eZnPP), using data from the Third National Health and Nutrition Examination Survey (NHANES III, 1988-1994). The SF at which circulating Hb begins to decrease and eZnPP begins to increase provides a physiological basis for identifying the onset of iron-deficient erythropoiesis. METHODS: We analyzed NHANES III cross-sectional data from 2616 apparently healthy children, aged 12-59 mo, and 4639 apparently healthy nonpregnant women, aged 15-49 y. We used restricted cubic spline regression models to determine SF thresholds for ID. RESULTS: SF thresholds identified by Hb and eZnPP did not differ significantly in children, 21.2 µg/L (95% confidence interval: 18.5, 26.5) and 18.7 µg/L (17.9, 19.7), and, in women, were similar although significantly different, 24.8 µg/L (23.4, 26.9) and 22.5 µg/L (21.7, 23.3). CONCLUSIONS: These NHANES results suggest that physiologically based SF thresholds are higher than the thresholds from expert opinion established during the same era. SF thresholds found using physiological indicators detect the onset of iron-deficient erythropoiesis, whereas the WHO thresholds identify a later, more severe stage of ID.

Iron Deficiency in the United States: Limitations in Guidelines, Data, and Monitoring of Disparities.

Iron deficiency and the more severe sequela, iron deficiency anemia, are public health problems associated with morbidity and mortality, particularly among pregnant women and younger children. The 1998 Centers for Disease Control and Prevention recommendations for prevention and control of iron deficiency in the United States is old and does not reflect recent evidence but is a foundational reference for many federal, clinical, and program guidelines. Surveillance data for iron deficiency are sparse at all levels, with critical gaps for pregnant women and younger children. Anemia, iron deficiency, and iron deficiency anemia are often conflated but should not be. Clinical guidelines for anemia, iron deficiency, and iron deficiency anemia give inconsistent recommendations, causing nonsystematic assessment of iron deficiency. Screening for iron deficiency typically relies on identifying anemia, despite anemia's low sensitivity for iron deficiency. In the National Health and Nutrition Examination Survey, more than 70% of iron deficiency is missed among pregnant women and children by relying on hemoglobin for iron deficiency screening. To improve assessment and diagnosis and strengthen surveillance, better and more complete data and updated foundational guidance on iron deficiency and anemia are needed that consider new evidence for measuring and interpreting laboratory results. (Am J Public Health. 2022;112(S8):S826-S835. https://doi.org/10.2105/AJPH.2022.306998).

Acceptability and Experiences with the Use of 3D Scans to Measure Anthropometry of Young Children in Surveys and Surveillance Systems from the Perspective of Field Teams and Caregivers.

Background: Portable systems using three-dimensional (3D) scan data to calculate young child anthropometry measurements in population-based surveys and surveillance systems lack acceptability data from field workers and caregivers. Objective: The aim was to assess acceptability and experiences with 3D scans measuring child aged 0-59 mo anthropometry in population-based surveys and surveillance systems in Guatemala, Kenya, and China (0-23 mo only) among field teams and caregivers of young children as secondary objectives of an external effectiveness evaluation. Methods: Manual data were collected twice and 12 images captured per child by anthropometrist/expert and assistant (AEA) field teams (individuals/country, n = 15/Guatemala, n = 8/Kenya, n = 6/China). Caregivers were interviewed after observing their child's manual and scan data collection. Mixed methods included an administered caregiver interview (Guatemala, n = 465; Kenya, n = 496; China, n = 297) and self-administered AEA questionnaire both with closed- and open-ended questions, and 6 field team focus group discussions (FGDs; Guatemala, n = 2; Kenya, n = 3; China, n = 1). Qualitative data were coded by 2 authors and quantitative data produced descriptive statistics. Mixed-method results were compared and triangulated. Results: Most AEAs were female with secondary or higher education. Approximately 80-90% of caregivers were the child's mother. To collect all anthropometry data, 62.1% of the 29 AEAs preferred scan, while 31% preferred manual methods. In FGDs, a key barrier for manual and scan methods was lack of child cooperation. Across countries, approximately 30% to almost 50% of caregivers said their child was bothered by each manual and scan method, while ≥95% of caregivers were willing to have their child measured by scans in the future. Conclusions: Use of 3D scans to calculate anthropometry measurements was generally at least as acceptable as manual anthropometry measurement among AEA field workers and caregivers of young children aged <60 mo, and in some cases preferred.

Physiologically based serum ferritin thresholds for iron deficiency in women of reproductive age who are blood donors.

Our objective is to develop a physiologically based method to determine serum ferritin thresholds for iron deficiency in healthy individuals. The current World Health Organization threshold of <15 µg/L for iron deficiency in women is based on expert opinion. We examined the relationship between serum ferritin and 2 independently measured indicators of iron-deficient erythropoiesis, soluble transferrin receptor (sTfR) and hemoglobin, in baseline data from 286 women, 20 to 49 years, who were first-time or reactivated donors in the Retrovirus Epidemiology Donor Study-II Donor Iron Status Evaluation (REDS-RISE) study. At lower serum ferritin concentrations, median sTfR increased as hemoglobin decreased. Using restricted cubic spline regression analysis to determine thresholds for iron-deficient erythropoiesis, the thresholds identified by sTfR (serum ferritin < 25.4 µg/L) and hemoglobin (serum ferritin < 25.3 µg/L) did not differ significantly. The thresholds found in the REDS-RISE study do not differ from those identified by sTfR (serum ferritin < 25.5 µg/L) and hemoglobin (serum ferritin < 26.6 µg/L) in a previous study of 5442 women, 20 to 49 years, in the US National Health and Nutrition Examination Survey 2003 to 2018 (P = .98 and 0.83, respectively). Although international comparisons are needed, these results with US data provide additional evidence for the potential usefulness of a physiologically based method to identify serum ferritin thresholds for iron deficiency.

Accuracy of a handheld 3D imaging system for child anthropometric measurements in population-based household surveys and surveillance platforms: an effectiveness validation study in Guatemala, Kenya, and China.

BACKGROUND: An efficacy evaluation of the AutoAnthro system to measure child (0-59 months) anthropometry in the United States found 3D imaging performed as well as gold-standard manual measurements for biological plausibility and precision. OBJECTIVES: We conducted an effectiveness evaluation of the accuracy of the AutoAnthro system to measure 0- to 59-month-old children's anthropometry in population-based surveys and surveillance systems in households in Guatemala and Kenya and in hospitals in China. METHODS: The evaluation was done using health or nutrition surveillance system platforms among 600 children aged 0-59 months (Guatemala and Kenya) and 300 children aged 0-23 months (China). Field team anthropometrists and their assistants collected manual and scan anthropometric measurements, including length or height, midupper arm circumference (MUAC), and head circumference (HC; China only), from each child. An anthropometry expert and assistant later collected both manual and scan anthropometric measurements on the same child. The expert manual measurements were considered the standard compared to field team scans. RESULTS: Overall, in Guatemala, Kenya, and China, for interrater accuracy, the average biases for length or height were -0.3 cm, -1.9 cm, and -6.2 cm, respectively; for MUAC were 0.9 cm, 1.2 cm, and -0.8 cm, respectively; and for HC was 2.4 cm in China. The inter-technical errors of measurement (inter-TEMs) for length or height were 2.8 cm, 3.4 cm, 5.5 cm, respectively; for MUAC were 1.1 cm, 1.5 cm, and 1.0 cm, respectively; and for HC was 2.8 cm in China. For intrarater precision, the absolute mean difference and intra-TEM (interrater, intramethod TEM) were 0.1 cm for all countries for all manual measurements. For scans, overall, absolute mean differences for length or height were 0.4-0.6 cm; for MUAC were 0.1-0.1 cm; and for HC was 0.4 cm. For the intra-TEM, length or height was 0.5 cm in Guatemala and China and 0.7 cm in Kenya, and other measurements were ≤0.3 cm. CONCLUSIONS: Understanding the factors that cause the many poor scan results and how to correct them will be needed prior to using this instrument in routine, population-based survey and surveillance systems.

Factors associated with anaemia in a nationally representative sample of nonpregnant women of reproductive age in Nepal.

We used cross-sectional data from the 2016 Nepal National Micronutrient Status Survey to evaluate factors associated with anaemia among a nationally representative sample of nonpregnant women 15- 49 years (n = 1, 918). Haemoglobin, biomarkers of iron status and other micronutrients, infection, inflammation, and blood disorders were assessed from venous blood. Soil-transmitted helminth and Helicobacter pylori infections were assessed from stool. Sociodemographic, household, and health characteristics and diet were ascertained by interview. We conducted bivariate analyses between candidate predictors and anaemia (haemoglobin <12.0 g/ dL, altitude- and smoking-adjusted). Candidate predictors that were significant in bivariate models (P < 0.05) were included in the multivariable logistic regression model, accounting for complex sampling design. Anaemia prevalence was 20.2% (95% confidence interval [CI] [17.6, 22.8]). Associated with reduced anaemia odds were living in the Mountain and Hill ecological zones relative to the Terai (adjusted odds ratio [AOR] 0.35, 95% CI [0.21, 0.60] and AOR 0.41, 95% CI [0.29, 0.59], respectively), recent cough (AOR 0.56, 95% CI [0.38, 0.82]), hormonal contraceptive use (AOR 0.58; 95% CI [0.38, 0.88]), ln ferritin (micrograms per litre; AOR 0.43, 95% CI [0.35, 0.54]), and ln retinol binding protein (micrograms per litre; AOR 0.20, 95% CI [0.11, 0.37]). Residing in a house with an earth floor (AOR 1.74, 95% CI [1.18, 2.56]), glucose-6- phosphate dehydrogenase deficiency (AOR 2.44, 95% CI [1.66, 3.60]), and haemoglobinopathies (AOR 6.15, 95% CI [3.09, 12.26]) were associated with increased anaemia odds. Interventions that improve micronutrient status, ensure access to hormonal birth control, and replace dirt floors to reduce infection risk might help reduce anaemia in this population.

Factors associated with anaemia among adolescent boys and girls 10-19 years old in Nepal.

We used data from the 2016 Nepal National Micronutrient Status Survey to evaluate factors associated with anaemia (World Health Organization cut-points using altitude- and smoking-adjusted haemoglobin [Hb]) among nationally representative samples of adolescents 10-19 years. Hb, biomarkers of micronutrients, infection and inflammation were assessed from venous blood. Sociodemographic and household characteristics, dietary diversity, pica and recent morbidity were ascertained by interview. We explored bivariate relationships between candidate predictors and anaemia among boys (N = 967) and girls (N = 1,680). Candidate predictors with P < 0.05 in bivariate analyses were included in sex-specific multivariable logistic regression models. Anaemia prevalence was 20.6% (95% confidence interval [CI] [17.1, 24.1]) among girls and 10.9% (95% CI [8.2, 13.6]) among boys. Among girls, living in the Mountain and Hill ecological zones relative to the Terai (adjusted odds ratio [AOR] 0.28, 95% CI [0.15, 0.52] and AOR 0.42, 95% CI [0.25, 0.73], respectively), ln ferritin (µg/L) (AOR 0.53, 95% CI [0.42, 0.68]) and ln retinol binding protein (RBP) (µmol/L) (AOR 0.08, 95% CI [0.04, 0.16]) were associated with reduced anaemia odds. Older age (age in years AOR 1.19, 95% CI [1.12, 1.27]) and Janajati ethnicity relative to the Muslim ethnicity (AOR 3.04, 95% CI [1.10, 8.36]) were associated with higher anaemia odds. Among boys, ln RBP [µmol/L] (AOR 0.25, 95% CI [0.10, 0.65]) and having consumed flesh foods (AOR 0.57, 95% CI [0.33, 0.99]) were associated with lower anaemia odds. Open defecation (AOR 2.36, 95% CI [1.15, 4.84]) and ln transferrin receptor [mg/L] (AOR 3.21, 95% CI [1.25, 8.23]) were associated with increased anaemia odds. Anaemia among adolescents might be addressed through effective public health policy and programs targeting micronutrient status, diet and sanitation.

The VitMin Lab Sandwich-ELISA Assays for Iron and Inflammation Markers Compared Well with Clinical Analyzer Reference-Type Assays in Subsamples of the Nepal National Micronutrient Status Survey.

BACKGROUND: The low cost and small specimen volume of the VitMin Lab ELISA assays for serum ferritin (Fer), soluble transferrin receptor (sTfR), C-reactive protein (CRP), and α-1-acid glycoprotein (AGP) have allowed their application to micronutrient surveys conducted in low-resource countries for ∼2 decades. OBJECTIVES: We conducted a comparison between the ELISA and reference-type assays used in the US NHANES. METHODS: Using the Roche clinical analyzer as a reference, we measured random subsets of the 2016 Nepal National Micronutrient Status Survey (200 serum samples from children aged 6-59 mo; 100 serum samples from nonpregnant women) for Fer, sTfR, CRP, and AGP. We compared the combined data sets with the ELISA survey results using descriptive analyses. RESULTS: The Lin's concordance coefficients between the 2 assays were ≥0.89 except for sTfR (Lin's ρ = 0.58). The median relative difference to the reference was as follows: Fer, -8.5%; sTfR, 71.2%; CRP, -19.5%; and AGP, -8.2%. The percentage of VitMin samples agreeing within ±30% of the reference was as follows: Fer, 88.5%; sTfR, 1.70%; CRP, 74.9%; and AGP, 92.9%. The prevalence of abnormal results was comparable between the 2 assays for Fer, CRP, and AGP, and for sTfR after adjusting to the Roche assay. Continued biannual performance (2007-2019) of the VitMin assays in CDC's external quality assessment program (6 samples/y) demonstrated generally acceptable performance. CONCLUSIONS: Using samples from the Nepal survey, the VitMin ELISA assays produced mostly comparable results to the Roche reference-type assays for Fer, CRP, and AGP. The lack of sTfR assay standardization to a common reference material explains the large systematic difference observed for sTfR, which could be corrected by an adjustment equation pending further validation. This snapshot comparison together with the long-term external quality assessment links the survey data generated by the VitMin Lab to the Roche assays used in NHANES.

Evaluation of Hemoglobin Cutoff Levels to Define Anemia Among Healthy Individuals.

Importance: Anemia, defined as low hemoglobin (Hb) concentration insufficient to meet an individual's physiological needs, is the most common blood condition worldwide. Objective: To evaluate the current World Health Organization (WHO) Hb cutoffs for defining anemia among persons who are apparently healthy and to assess threshold validity with a biomarker of tissue iron deficiency and physiological indicator of erythropoiesis (soluble transferrin receptor [sTfR]) using multinational data. Design, Setting, and Participants: In this cross-sectional study, data were collected and evaluated from 30 household, population-based nutrition surveys of preschool children aged 6 to 59 months and nonpregnant women aged 15 to 49 years during 2005 to 2016 across 25 countries. Data analysis was performed from March 2020 to April 2021. Exposure: Anemia defined according to WHO Hb cutoffs. Main Outcomes and Measures: To define the healthy population, persons with iron deficiency (ferritin <12 ng/mL for children or <15 ng/mL for women), vitamin A deficiency (retinol-binding protein or retinol <20.1 µg/dL), inflammation (C-reactive protein >0.5 mg/dL or α-1-acid glycoprotein >1 g/L), or known malaria were excluded. Survey-specific, pooled Hb fifth percentile cutoffs were estimated. Among individuals with Hb and sTfR data, Hb-for-sTfR curve analysis was conducted to identify Hb inflection points that reflect tissue iron deficiency and increased erythropoiesis induced by anemia. Results: A total of 79 950 individuals were included in the original surveys. The final healthy sample was 13 445 children (39.9% of the original sample of 33 699 children; 6750 boys [50.2%]; mean [SD] age 32.9 [16.0] months) and 25 880 women (56.0% of the original sample of 46 251 women; mean [SD] age, 31.0 [9.5] years). Survey-specific Hb fifth percentile among children ranged from 7.90 g/dL (95% CI, 7.54-8.26 g/dL in Pakistan) to 11.23 g/dL (95% CI, 11.14-11.33 g/dL in the US), and among women from 8.83 g/dL (95% CI, 7.77-9.88 g/dL in Gujarat, India) to 12.09 g/dL (95% CI, 12.00-12.17 g/dL in the US). Intersurvey variance around the Hb fifth percentile was low (3.5% for women and 3.6% for children). Pooled fifth percentile estimates were 9.65 g/dL (95% CI, 9.26-10.04 g/dL) for children and 10.81 g/dL (95% CI, 10.35-11.27 g/dL) for women. The Hb-for-sTfR curve demonstrated curvilinear associations with sTfR inflection points occurring at Hb of 9.61 g/dL (95% CI, 9.55-9.67 g/dL) among children and 11.01 g/dL (95% CI, 10.95-11.09 g/dL) among women. Conclusions and Relevance: Current WHO cutoffs to define anemia are higher than the pooled fifth percentile of Hb among persons who are outwardly healthy and from nearly all survey-specific estimates. The lower proposed Hb cutoffs are statistically significant but also reflect compensatory increased erythropoiesis. More studies based on clinical outcomes could further confirm the validity of these Hb cutoffs for anemia.

Physiologically based serum ferritin thresholds for iron deficiency in children and non-pregnant women: a US National Health and Nutrition Examination Surveys (NHANES) serial cross-sectional study.

BACKGROUND: Serum ferritin concentrations are the most widely used indicator for iron deficiency. WHO determined that insufficient data are available to revise the serum ferritin thresholds of less than 12 µg/L for children and less than 15 µg/L for women, which were developed on the basis of expert opinion, to define iron deficiency. We aimed to derive new physiologically based serum ferritin concentration thresholds for iron deficiency in healthy young children and non-pregnant women using data from the US National Health and Nutrition Examination Survey (NHANES). METHODS: In this serial cross-sectional study, we examined the relationship of serum ferritin with two independent indicators of iron-deficient erythropoiesis, haemoglobin and soluble transferrin receptor (sTfR), in children (12-59 months) and non-pregnant women (15-49 years) using cross-sectional NHANES data from 2003-06, 2007-10, and 2015-18. NHANES is a US national stratified multistage probability sample that includes a household interview followed by a standardised physical examination in a mobile examination centre. We excluded individuals with missing serum ferritin, sTfR, haemoglobin, or white blood cell counts measurements; non-pregnant women with missing C-reactive protein (CRP), alanine aminotransferase (ALT) or aspartate aminotransferase (AST) data were also excluded. In addition, individuals with infection (white blood cell counts >10·0×109/L) and non-pregnant women with possible liver disease (ALT >70 IU/L or AST >70 IU/L) and inflammation (CRP >5·0 mg/L) were excluded. We examined distributions of haemoglobin and sTfR with serum ferritin and used restricted cubic spline regression models to determine serum ferritin thresholds for iron-deficient erythropoiesis. FINDINGS: 5964 children and 10 462 non-pregnant women had physical examinations and were screened for inclusion in the study, of whom 2569 (43·1%) children and 7498 (71·7%) non-pregnant women were included. At lower serum ferritin concentrations, median haemoglobin concentration decreased as sTfR concentration increased, with each varying in a curvilinear manner. Using restricted cubic spline plateau points to determine the onset of iron-deficient erythropoiesis, the serum ferritin thresholds identified by haemoglobin and sTfR concentrations were not different. For children, the haemoglobin identified serum ferritin threshold was 19·9 µg/L (95% CI 18·8-22·6) and the sTfR identified serum ferritin threshold was 20·0 µg/L (19·4-20·9; p=0·89). For women the haemoglobin identified serum ferritin threshold was 25·2 µg/L (24·2-26·2) and the sTfR identified serum ferritin threshold was 24·0 µg/L (23·3-24·6; p=0·05). INTERPRETATION: The association between two independent indicators of iron-deficient erythropoiesis, haemoglobin and sTfR, identified serum ferritin concentration thresholds of about 20 µg/L for children and 25 µg/L for non-pregnant women, providing physiological evidence of potential new thresholds for consideration when determining the prevalence and distribution of iron deficiency in populations. In healthy children and non-pregnant women, physiologically based thresholds for iron deficiency might be more clinically and epidemiologically relevant than those based on expert opinion. Validation of this physiologically based approach in non-US populations might help the international harmonisation of serum ferritin thresholds for iron deficiency. FUNDING: None.

Effects of prenatal micronutrients supplementation timing on pregnancy-induced hypertension: Secondary analysis of a double-blind randomized controlled trial.

In this secondary analysis of data from a double-blind randomized controlled trial (clinicaltrials.gov identifier: NCT00133744) of micronutrient supplementation (multiple micronutrients [MMN], iron-folic acid [IFA] and folic acid [FA] alone), we examined the potential modifying effect of gestational age at enrolment on the association of antenatal supplementation and pregnancy-induced hypertension (PIH). We included 18,775 nulliparous pregnant women with mild or no anaemia who were enrolled at 20 weeks of gestation or earlier from five counties of northern China. Women were randomly assigned to receive daily FA, IFA or MMN from enrolment until delivery. We used logistic regression to evaluate the association between PIH and timing of micronutrient supplementation. The incidence of PIH was statistically significantly lower among women who began MMN supplementation before 12 gestational weeks compared with women who began MMN supplementation at 12 weeks or later (RR = 0.74, 95% CI: 0.60-0.91). A similar protective effect was observed for both early-onset (<28 weeks, RR 0.45, 0.21-0.96) and late-onset of PIH (≥28 weeks, RR 0.77, 0.63-0.96). No statistically significant association was observed between PIH occurrence and timing of supplementation for FA or IFA. Maternal MMN supplementation and antenatal enrolment during the first trimester of pregnancy appeared to be of importance in preventing both early- and late-onset of PIH.

Combined infant and young child feeding with small-quantity lipid-based nutrient supplementation is associated with a reduction in anemia but no changes in anthropometric status of young children from Katanga Province of the Democratic Republic of Congo: a quasi-experimental effectiveness study.

BACKGROUND: Small-quantity lipid-based nutrient supplements (SQ-LNS) are efficacious in controlled settings; data are scarce on the effectiveness utilizing health care delivery platforms. OBJECTIVE: We evaluated the impact of an infant young child feeding (IYCF)-SQ-LNS intervention on anemia and growth in children aged 6-18 mo in the Democratic Republic of Congo following a quasi-experimental effectiveness design. METHODS: An intervention health zone (HZ) received enhanced IYCF including improved counseling on IYCF during pregnancy until 12 mo after birth and daily use of SQ-LNS for infants 6-12 mo; the control HZ received the standard IYCF package. We analyzed data from 2995 children, collected in repeated cross-sectional surveys. We used adjusted difference-in-difference analyses to calculate changes in anemia, iron and vitamin A deficiencies, stunting, wasting, and underweight. RESULTS: Of mothers, 70.5% received SQ-LNS at least once in the intervention HZ, with 99.6% of their children consuming SQ-LNS at least once. The mean number of batches of SQ-LNS (28 sachets per batch, 6 batches total) received was 2.3 ± 0.8 (i.e., 64.4 ± 22.4 d of SQ-LNS). The enhanced program was associated with an 11.0% point (95% CI: -18.1, -3.8; P < 0.01) adjusted relative reduction in anemia prevalence and a mean +0.26-g/dL (95% CI: 0.04, 0.48; P = 0.02) increase in hemoglobin but no effect on anthropometry or iron or vitamin A deficiencies. At endline in the intervention HZ, children aged 8-13 mo who received ≥3 monthly SQ-LNS batch distributions had higher anthropometry z scores [length-for-age z score (LAZ): +0.40, P = 0.04; weight-for-age z score (WAZ): +0.37, P = 0.04] and hemoglobin (+0.65 g/dL, P = 0.007) and a lower adjusted prevalence difference of stunting (-16.7%, P = 0.03) compared with those who received none. CONCLUSIONS: The enhanced IYCF-SQ-LNS intervention using the existing health care delivery platform was associated with a reduction in prevalence of anemia and improvement in mean hemoglobin. At endline among the subpopulation receiving ≥3 mo of SQ-LNS, their LAZ, WAZ, and hemoglobin improved. Future research could explore contextual tools to maximize coverage and intake adherence in programs using SQ-LNS.

Comparing hemoglobin distributions between population-based surveys matched by country and time.

BACKGROUND: Valid measurement of hemoglobin is important for tracking and targeting interventions. This study compares hemoglobin distributions between surveys matched by country and time from The Demographic and Health Survey (DHS) Program and the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project. METHODS: Four pairs of nationally representative surveys measuring hemoglobin using HemoCue® with capillary (DHS) or venous (BRINDA) blood were matched by country and time. Data included 17,719 children (6-59 months) and 21,594 non-pregnant women (15-49 y). Across paired surveys, we compared distributional statistics and anemia prevalence. RESULTS: Surveys from three of the four countries showed substantial differences in anemia estimates (9 to 31 percentage point differences) which were consistently lower in BRINDA compared to DHS (2 to 31 points for children, 1 to 16 points for women). CONCLUSION: We identify substantial differences in anemia estimates from surveys of similar populations. Further work is needed to identify the cause of these differences to improve the robustness of anemia estimates for comparing populations and tracking improvements over time.

Age, Ethnicity, Glucose-6-Phosphate Dehydrogenase Deficiency, Micronutrient Powder Intake, and Biomarkers of Micronutrient Status, Infection, and Inflammation Are Associated with Anemia Among Children 6-59 Months in Nepal.

BACKGROUND: Anemia is a major concern for children in Nepal; however, little is known about context-specific causes of anemia. OBJECTIVE: We used cross-sectional data from the 2016 Nepal National Micronutrient Status Survey to evaluate factors associated with anemia in a nationally representative, population-based sample of children 6-59 mo (n = 1367). METHODS: Hemoglobin, biomarkers of iron status and other micronutrients, infection, inflammation, and blood disorders were assessed from venous blood samples. Soil-transmitted helminth (STH) and Helicobacter pylori infections were assessed from stool. Anthropometry was measured with standard procedures. Sociodemographic and household characteristics, diet, micronutrient powder (MNP) intake, pica, and morbidity recall were ascertained by caregiver interview. Multivariable logistic regression that accounted for complex sampling design, determined predictors of anemia (hemoglobin <11.0 g/dL, altitude adjusted); candidate predictors were variables with P < 0.05 in bivariate models. RESULTS: Anemia prevalence was 18.6% (95% CI: 15.8, 21.4). MNP intake [adjusted OR (AOR): 0.25, 95% CI: 0.07, 0.86], log (ln) ferritin (µg/L) (AOR: 0.49, 95% CI: 0.38, 0.64), and ln RBP (µmol/L) (AOR: 0.42, 95% CI: 0.18, 0.95) were associated with reduced odds of anemia. Younger age (6-23 mo compared with 24-59 mo; AOR: 2.29, 95% CI: 1.52, 3.46), other Terai ethnicities (AOR: 2.59, 95% CI: 1.25, 5.35) and Muslim ethnicities (AOR: 3.15, 95% CI: 1.30, 7.65) relative to Brahmin/Chhetri ethnicities, recent fever (AOR: 1.68, 95% CI: 1.08, 2.59), ln C-reactive protein (mg/L) (AOR: 1.23, 95% CI: 1.03, 1.45), and glucose-6-phosphate dehydrogenase deficiency (AOR: 2.84, 95% CI: 1.88, 4.30) were associated with increased odds of anemia. CONCLUSION: Both nonmodifiable and potentially modifiable factors were associated with anemia. Thus some but not all anemia might be addressed through effective public health policy, programs, and delivery of nutrition and infection prevention and control.

Predictors of micronutrient powder (MNP) knowledge, coverage, and consumption during the scale-up of an integrated infant and young child feeding (IYCF-MNP) programme in Nepal.

Large-scale programmes using micronutrient powders (MNPs) may not achieve maximum impact due to limited/inappropriate MNP coverage, consumption, and use. We identify predictors of MNP coverage, maternal knowledge of appropriate use, and child MNP consumption in Nepal. A cross-sectional survey was conducted in 2,578 mother-child pairs representative of children 6-23 months in two districts that were part of the post-pilot, scale-up of an integrated infant and young child feeding-MNP (IYCF-MNP) programme. Children aged 6-23 months were expected to receive 60 MNP sachets every 6 months from a female community health volunteer (FCHV) or health centre. Outcomes of interest were MNP coverage (ever received), maternal knowledge of appropriate use (correct response to seven questions), repeat coverage (receipt ≥ twice; among children 12-23 months who had received MNP at least once, n = 1342), and high intake (child consumed ≥75% of last distribution, excluding those with recent receipt/insufficient time to use 75% at recommended one-sachet-per-day dose, n = 1422). Multivariable log-binomial regression models were used to identify predictors of the four outcomes. Coverage, knowledge of appropriate use, and repeat coverage were 61.3%, 33.5%, and 45.9%, respectively. Among MNP receivers, 97.9% consumed MNP at least once and 38.9% of eligible children consumed ≥75% of last distribution. FCHV IYCF-MNP counselling was positively associated with knowledge, coverage, repeat coverage, and high intake; health worker counselling with knowledge and coverage indicators; and radio messages with coverage indicators only. FCHV counselling had the strongest association with knowledge, coverage, and high intake. Community-based counselling may play a vital role in improving coverage and intake in MNP programmes.

Data needed to respond appropriately to anemia when it is a public health problem.

Although the proportion of anemia amenable to change varies by population, the World Health Organization (WHO) criteria used to describe the public health severity of anemia are based on population prevalences. We describe the importance of measuring iron and other etiologic indicators to better understand what proportion of anemia could be responsive to interventions. We discuss the necessity of measuring inflammation to interpret iron biomarkers and documenting anemia of inflammation. Finally, we suggest assessing nonmodifiable genetic blood disorders associated with anemia. Using aggregated results from the Global Burden of Disease 2016, we compare population prevalence of anemia with years lived with disability (YLD) estimates, and the relative contributions of mild, moderate, and severe anemia to YLD. Anemia prevalences correlated with YLD and the relative proportion of moderate or severe anemia increased with anemia prevalence. However, individual-level survey data revealed irregular patterns between anemia prevalence, the prevalence of moderate or severe anemia, and the prevalence of iron deficiency anemia (IDA). We conclude that although the WHO population prevalence criteria used to describe the public health severity of anemia are important for policymaking, etiologic-specific metrics that take into account IDA and other causes will be necessary for effective anemia control policies.

Reexamination of hemoglobin adjustments to define anemia: altitude and smoking.

The correct interpretation of hemoglobin (Hb) to identify anemia requires adjusting for altitude and smoking. Current adjustments were derived using data collected before 1985, from low-income preschool-aged children (PSC) in the United States and indigenous men in Peru for altitude, and from White women of reproductive age (WRA) in the United States for smoking. Given the oldness and limited representativeness of these data, we reexamined associations between Hb and altitude and/or smoking using 13 population-based surveys and 1 cohort study each conducted after 2000. All WHO regions except South-East Asia were represented. The dataset included 68,193 observations among PSC (6-59 months) and nonpregnant WRA (15-49 years) with data on Hb and altitude (-28 to 4000 m), and 19,826 observations among WRA with data on Hb and smoking (status or daily cigarette quantity). Generalized linear models were used to assess the robustness of associations under varying conditions, including controlling for inflammation-corrected iron and vitamin A deficiency. Our study confirms that Hb should be adjusted for altitude and/or smoking; these adjustments are additive. However, recommendations for Hb adjustment likely need updating. Notably, current recommendations may underadjust Hb for light smokers and for those residing at lower altitudes and overadjust Hb for those residing at higher altitudes.