Assessing Accuracy and Precision of Hemoglobin Determination in Venous, Capillary Pool, and Single-Drop Capillary Blood Specimens Using three Different HemoCue® Hb Models: The Multicountry Hemoglobin Measurement (HEME) Study.

BACKGROUND: Anemia prevalence estimates reported in population surveys can vary based on the blood specimen source (capillary or venous) and analytic device (hematology autoanalyzers or portable hemoglobinometers) used for hemoglobin (Hb) determination. OBJECTIVES: This study aimed to compare accuracy and precision of Hb measurement in three blood specimen types on three models of hemoglobinometers against the results from venous blood from the same individuals measured on automated analyzers (AAs). METHODS: This multisite (Cambodia, Ethiopia, Guatemala, Lebanon, Nigeria, and Tanzania) study assessed Hb measurements in paired venous and capillary blood specimens from apparently healthy women (aged 15-49 y) and children (aged 12-59 mo) using three HemoCue® Hb models (201+, 301, and 801). Measurements were compared against reference values: venous blood in hematology AA and adjusted via regression calibration or mean difference in HemoCue® Hb. Venous, capillary pool, and single-drop capillary blood specimens were assessed for accuracy and precision. RESULTS: Venous blood measured using HemoCue® Hb 301 exhibited a positive mean error, whereas responses in HemoCue® Hb 201+ and 801 were nondirectional compared with the reference. Adjustment with the reference harmonized mean errors for all devices across study sites to <1.0 g/L using venous blood. Precision was highest for venous blood (±5-16 g/L) in all sites, lowest for single-drop capillary (±9-37 g/L), and intermediate (±9-28 g/L) for capillary pool blood specimen. Imprecision differed across sites, especially with both capillary blood specimens, suggesting different levels of personnel skills. CONCLUSIONS: Findings suggest that venous blood is needed for accurate and precise Hb determination. Single-drop capillary blood use should be discouraged owing to high measurement variability. Further research should evaluate the viability and reliability of capillary pool blood for this purpose. Accuracy of HemoCue® Hb devices can be improved via standardization against results from venous blood assessed using AA.

Exploring the Anemia Ecology: A New Approach to an Old Problem.

Our ability to identify anemia and all its permutations demands an approach that integrates the key elements of a complex "ecology," which intertwines biology and mechanistic aspects of nutrients with both the health status and underlying factors-physical, economic, social, behavioral, demographic, and environmental. The complexity of anemia demands an ecologic approach that appreciates systems biology, translates sensitive and specific assessment methodologies and interventions, and ultimately improves clinical and public health outcomes. This series of technical papers on anemia by the U.S. Agency for International Development (USAID) Advancing Nutrition Anemia Task Force (ATF) is a first step in translating our ecologic approach to anemia with a view toward balancing research with its translation to effective programs, interventions, and policy. This introductory overview describes the components of our ecologic approach-linking the biology of anemia with its assessment and using the learning from that confluence to devise context-specific interventions. This introductory review briefly discusses the topics that underlie the biology and primary etiologies of anemia and presents a framework for public health assessment of anemia, leading to appropriate public health interventions. The other 3 manuscripts in the supplement provide the details of the arguments laid out in the introduction.

Improving Anemia Assessment in Clinical and Public Health Settings.

We aim to provide a practical approach to assess anemia and its primary causes, both in clinical settings and in the context of public health programs. Anemia remains a global challenge; thus, to achieve goals for anemia reduction and assess progress, standardized approaches are required for the assessment of anemia and its causes. We first provide a brief review of how to assess anemia, based on hemoglobin concentrations and cutoffs that correspond to age, sex, and physiologic status. Next, we discuss how to assess the likely causes of anemia in different settings. The causes of anemia are classified as non-nutritional (for example, because of infection, inflammation, blood loss, or genetic disorders) or nutrition-specific (for example, because of deficiencies of iron, vitamin A, riboflavin, vitamin B12, or folate). There is an important overlap between these 2 categories, such as the increased likelihood of iron deficiency in the context of inflammation. Given the multifaceted nature of anemia etiology, we introduce a framework for anemia assessment based on the "ecology of anemia," which recognizes its many overlapping causes. This conceptual framework is meant to inform what data on anemia causes may need to be collected in population surveys. The framework has a supporting table with information on the diagnostic tests, biomarkers and proposed cutoffs, characteristics, and feasibility of collecting the myriad information that can help elucidate the anemia etiology. We also provide examples of how this framework can be applied to interpret the anemia risk factor data from population-based surveys that can inform decisions about context-specific interventions. Finally, we present research gaps and priorities related to anemia assessment.

Validation of hemoglobin measurement in venous blood using HemoCue for the Ensanut 2022.

OBJECTIVE: To validate hemoglobin (Hb) concentration in venous blood (VB) using the HemoCue 201+ in a subsample of children and women from the Mexican National Health and Nutrition Survey 2022. MATERIALS AND METHODS: Prior to field work 50 HemoCue 201+ devices were verified using venous blood. During the field work 57 children (aged 1-11) and 62 women (aged 12-49) donated 3 mL of VB each. Hb was measured in each device of HemoCue 201+ and in a hematologic autoanalyzer for the validation. RESULTS: No significant bias was found in most of the devices. An adjustment criterion was used for 22 devices. Hb mean difference results were -0.049±0.578 g/dL in children and -0.098±0.628 g/dL in women. CONCLUSIONS: The HemoCue 201+ is a valid tool for estimating Hb concentration to produce reliable estimates of anemia prevalence when using venous blood.

Systematic review of metrics used to characterise dietary nutrient supply from household consumption and expenditure surveys.

OBJECTIVE: To review existing publications using Household Consumption and Expenditure Survey (HCES) data to estimate household dietary nutrient supply to (1) describe scope of available literature, (2) identify the metrics reported and parameters used to construct these metrics, (3) summarise comparisons between estimates derived from HCES and individual dietary assessment data and (4) explore the demographic and socio-economic sub-groups used to characterise risks of nutrient inadequacy. DESIGN: This study is a systematic review of publications identified from online databases published between 2000 to 2019 that used HCES food consumption data to estimate household dietary nutrient supply. Further publications were identified by 'snowballing' the references of included database-identified publications. SETTING: Publications using data from low- and lower-middle income countries. RESULTS: In total, fifty-eight publications were included. Three metrics were reported that characterised household dietary nutrient supply: apparent nutrient intake per adult-male equivalent per day (n 35), apparent nutrient intake per capita per day (n 24) and nutrient density (n 5). Nutrient intakes were generally overestimated using HCES food consumption data, with several studies finding sizeable discrepancies compared with intake estimates based on individual dietary assessment methods. Sub-group analyses predominantly focused on measuring variation in household dietary nutrient supply according to socio-economic position and geography. CONCLUSION: HCES data are increasingly being used to assess diets across populations. More research is needed to inform the development of a framework to guide the use of and qualified interpretation of dietary assessments based on these data.

Inventory on the dietary assessment tools available and needed in africa: a prerequisite for setting up a common methodological research infrastructure for nutritional surveillance, research, and prevention of diet-related non-communicable diseases.

OBJECTIVE: To carry out an inventory on the availability, challenges, and needs of dietary assessment (DA) methods in Africa as a pre-requisite to provide evidence, and set directions (strategies) for implementing common dietary methods and support web-research infrastructure across countries. METHODS: The inventory was performed within the framework of the "Africa's Study on Physical Activity and Dietary Assessment Methods" (AS-PADAM) project. It involves international institutional and African networks. An inventory questionnaire was developed and disseminated through the networks. Eighteen countries responded to the dietary inventory questionnaire. RESULTS: Various DA tools were reported in Africa; 24-Hour Dietary Recall and Food Frequency Questionnaire were the most commonly used tools. Few tools were validated and tested for reliability. Face-to-face interview was the common method of administration. No computerized software or other new (web) technologies were reported. No tools were standardized across countries. CONCLUSIONS: The lack of comparable DA methods across represented countries is a major obstacle to implement comprehensive and joint nutrition-related programmes for surveillance, programme evaluation, research, and prevention. There is a need to develop new or adapt existing DA methods across countries by employing related research infrastructure that has been validated and standardized in other settings, with the view to standardizing methods for wider use.

Predicted efficacy of the Palestinian wheat flour fortification programme: complementary analysis of biochemical and dietary data.

OBJECTIVE: To utilize complementary biochemical and dietary data collected before the initiation of national flour fortification to (i) identify micronutrient insufficiencies or deficiencies and dietary inadequacies in Palestinian women and children in vulnerable communities and (ii) assess the suitability of the current wheat flour fortification formula. DESIGN: Quantitative dietary intake questionnaires were administered and fasting venous blood samples collected in randomly selected households in Gaza City and Hebron. The impact of fortification was simulated by estimating the additional micronutrient content of fortified wheat flour. SETTING: Households in Gaza City and Hebron that were not receiving food aid from social programmes. SUBJECTS: Non-pregnant women (18-49 years) and children aged 36-83 months. RESULTS: The micronutrients with highest prevalence of insufficiency were vitamin D in women (84-97 % with serum 25-hydroxyvitamin D <50 nmol/l) and vitamin B12 in women and children (43-82 % with serum B12 <221 pmol/l). Deficiencies of vitamin A, Fe and Zn were also of public health concern. Current levels of wheat flour fortificants were predicted to improve, but not eliminate, micronutrient intake inadequacies. Modification of fortificant concentrations of vitamin D, thiamin, vitamin B12, Zn and folic acid may be indicated. CONCLUSIONS: Micronutrient insufficiencies or deficiencies and intake inadequacies were prevalent based on either biochemical or dietary intake criteria. Adjustments to the current fortification formula for wheat flour are necessary to better meet the nutrient needs of Palestinian women and children.

Systematic review of studies evaluating urinary iodine concentration as a predictor of 24-hour urinary iodine excretion for estimating population iodine intake.

OBJECTIVE: To examine the usefulness of "spot" urine iodine concentrations (UICs) in predicting 24-hour urine iodine excretion (UIE) for estimating average population iodine intake. METHODS: An electronic literature search was conducted for articles published through 19 May 2013 in MEDLINE (from 1950), EMBASE (from 1980), and the Cochrane Library (from 1993) using the terms "urinary excretion (timed or spot or random) and (24 h or 24 hour), iodine (iodine deficiency), iodine (intake)," and "urine (timed, spot, random, 24-hour)." Full-text articles about studies that examined > 40 healthy human subjects and measured UIE using the 24-hour urine collection method and UIC and/or UIE using one alternative method (spot (random), timed, and "overnight" (first morning urine), fasting or not fasting) were selected and reviewed. RESULTS: The review included data from 1 434 participants across the six studies that met the inclusion criteria. The main statistical methods for comparing data from the 24-hour urine collections with the values obtained from the alternative method(s) were either regression (ß) or correlation (r) coefficients and concordance analysis through Bland-Altman plots. The urine samples collected using the alternative methods were subject to greater intra-individual and inter-individual variability than the 24-hour urine collections. There was a wide range in coefficient values for the comparisons between 24-hour URE measured in 24-hour urine collection and 24-hour UIE estimated using the alternative sampling methods. No alternative sampling method (spot, timed, or "overnight") was appropriate for estimating 24-hour UIE. CONCLUSIONS: The results of this systematic review suggest current data on UICs as a means of predicting 24-hour UIE for estimating population sodium intake are inadequate and highlight the need for further methodological investigations.

Firm-Level and Public-Sector Costs Make Small-Scale Maize Flour Fortification Challenging in Uganda.

BACKGROUND: Maize flour in Uganda is milled by hundreds of enterprises, mostly small- (5-20 metric tons [MT]/day) and micro-scale (<5 MT/day) mills or firms. A mandatory maize flour fortification program exists for medium-scale mills (>20 MT/day) and policymakers are considering including smaller-scale millers. OBJECTIVE: We estimated the private and public costs of maize flour fortification at different scales and explored their implications for extending the mandatory fortification to include smaller-scale mills. METHODS: We used secondary data on the structure of the maize flour market and primary data on milling and fortification costs to estimate mill and regulatory costs at 3 scales of flour production: micro, small, and medium. RESULTS: For micro-, small-, and medium-size operations, respectively, operational costs of fortification were US$13, US$9, and US$7 per metric ton (MT) of maize flour, which represented 20%, 16%, and 16% of annual operating costs, and the ratio of fortification equipment cost to mill equipment costs was higher for micro-scale mills (2.7) than for small- (0.38) and medium-scale (0.54) maize mills. Governmental regulatory costs rise if smaller-scale mills are included due to the increased number of facility inspections. CONCLUSIONS: Fortification and regulatory costs increase as production scale decreases. Up-front capital costs of fortification would be daunting for micro- and small-scale mills. Medium-scale mills, which supply social protection programs, might be able to manage fortification costs and other challenges. Decision-makers should consider all costs and cost burdens, and the realities of enforcement capabilities before expanding fortification programs to include smaller-scale operations.

Plain language titleCosts of Small-scale Maize Flour Fortification in UgandaPlain language summaryA study of the costs of adding vitamins and minerals by small-scale maize flour millers in Uganda was undertaken to understand if it would be commercially beneficial from a business and operations perspective for them to do so, and if requiring them to do so would impose additional cost burdens on government to ensure that fortification standards were met.Why was the study done?Maize flour is consumed by the majority of Uganda's population, especially the rural poor. If the flour were fortified, it would reduce vitamin and mineral deficiencies among those at risk. The most important constraint to market-wide fortification is the presence of many small-scale mills or firms that neither have the resources nor the technology to adopt and sustain the fortification process. To date, no study has been done to calculate the costs that small-scale mills would have to face to fortify flour, or what the cost implications for government would be for including smaller-scale mills in a national fortification program, including the costs of enforcing regulations.What did the researchers do?The researchers interviewed millers of several scales of operation to collect cost information on their operations and interviewed representatives of government regulatory bodies to estimate the costs of testing maize flour to ensure compliance with regulations. Researchers estimated the cost to the mills of adding fortification to their business models, and the impacts on the government costs (eg, testing additional samples, etc.) of including smaller-scale mills in the fortification program.What did the researchers find?The researchers looked at 3 different types of mills based on their capacity to mill maize flour­micro-scale firms milled less than 5 metric tons (MT) a day, small-scale firms milled 5 to 20 MT per day, and medium-scale firms milled over 20 MT a day. For micro-, small-, and medium-size firms, respectively, fortification increased operational costs by US$13, US$9, and US$7 per MT of maize flour, which represented 20%, 16%, and 16% of annual operating costs. Similarly, governmental regulatory costs rose if smaller-scale mills were included because of the increased number of facility inspections required since the current legislation requires mandatory annual inspections.What do the findings mean?Fortification and regulatory costs increase as the scale of production by the millers decreases. If fortification by small- and micro-scale mills were made mandatory, up-front costs of fortification equipment and materials would be daunting for micro- and small-scale millers. Ugandan medium-scale millers might manage fortification costs and other challenges, but only if the social protection programs they supplied were of sufficient volume and regularity.

The Value of an Ecological Approach to Improve the Precision of Nutritional Assessment: Addressing Contributors and Implications of the "Multiple Burdens of Malnutrition".

Globally, children are exposed to multiple health risks associated with diet and nutrition. Rather than simply being a condition of having too much or too little food, malnutrition is more a syndrome comprising multiple burdens of coexisting and reciprocal malnutrition, infection, or other conditions. Importantly, children with such syndromes (e.g., stunting and anemia, which are neither specific nor necessarily sensitive to nutritional status) are more likely to also have irreversible functional outcomes such as poor growth, impaired immune function, or cognitive delays. The global health community has identified nutrition-related targets (e.g., Sustainable Development Goals (SDGs) and World Health Organization (WHO) Global Nutrition Targets) that, for multiple reasons, are difficult to address. Moreover, as the complexity of the global health context increases with persistent pandemics of infectious diseases and the rising prevalence of noncommunicable diseases, there is a growing appreciation that conditions selected as nutrition/health targets indeed represent syndromes for which nutritional status serves as both an input and outcome. In recognition of the impact of these combined challenges and the role of the multiple manifestations of malnutrition, we suggest an approach to nutritional assessment that is intended to improve the precision of context-specific, equitable approaches to health promotion, disease prevention, and treatment.

Emerging Evidence and Critical Issues with the Use of Single-Drop Capillary Blood for the Measurement of Hemoglobin Concentration in Population-Level Anemia Surveys.

Accurate and precise measurement of hemoglobin concentration is critical for reliable estimations of anemia prevalence at the population level. When systematic and/or random error are introduced in hemoglobin measurement, estimates of anemia prevalence might be significantly erroneous and, hence, limit their usefulness. For decades, single-drop capillary blood has been the most common blood source used for the measurement of hemoglobin concentration in surveys, especially in low-income and middle-income countries. In this study, we highlight historical and emerging evidence that single-drop capillary blood introduces a high degree of random error (variability) to hemoglobin estimates, leading to less reliable estimates of anemia prevalence at the population level. At present, the best practice is to collect and use venous blood for measurement of hemoglobin with an automated hematology analyzer, following standard operating procedures and quality assurance measures. Where use of an automated analyzer is not possible, the analysis of venous blood in a point-of-care hemoglobinometer by trained phlebotomists or specimen collectors should be considered. A forthcoming systematic review will provide additional evidence on the accuracy and precision of single-drop capillary blood for hemoglobin assessment. In the meantime, we raise caution when using single-drop capillary blood for hemoglobin measurement as it can result in inaccurate hemoglobin estimates and less reliable anemia prevalence estimates.

The importance of using food and nutrient intake data to identify appropriate vehicles and estimate potential benefits of food fortification in Uganda.

BACKGROUND: Concern over micronutrient inadequacies in Uganda has prompted the introduction of mass fortification. OBJECTIVE: To use food intake to determine nutrient inadequacies in children aged 24 to 59 months and nonpregnant women of reproductive age, and to model the adequacy of mass fortification. METHODS: Data were collected by the 24-hour recall method in three regions. Usual nutrient intakes were calculated by adjusting actual intake distribution for the intraindividual variance. The impact of fortification on intake adequacy was simulated. RESULTS: The nutrients with the highest prevalence of inadequate intake across regions were vitamin A (30% to 99%), vitamin B12 (32% to 100%), iron (55% to 89%), zinc (18% to 82%), and calcium (84% to 100%). According to simulations, fortification of vegetable oil and sugar with vitamin A would reduce the prevalence of vitamin A inadequacy in the Western and Northern regions; in Kampala it would eliminate vitamin A inadequacy but would cause 2% to 48% of children to exceed the Tolerable Upper Intake Level (UL). The proposed fortification of wheat flour would reduce the prevalence of inadequate intakes of thiamine, riboflavin, folate, and niacin in Kampala, but would have little impact in the other two regions due to low flour consumption. CONCLUSIONS: Micronutrient fortification of vegetable oil and sugar in all regions and of wheat flour in Kampala would reduce the prevalence of micronutrient inadequacies. However, the wheat flour formulation should be modified to better meet requirements, and the vitamin A content in sugar should be reduced to minimize the risk of high intakes. Maize flour may be suitable for targeted fortification, but prior consolidation of the industry would be required for maize flour to become a good vehicle for mass fortification.

Diagnosing anemia: Challenges selecting methods, addressing underlying causes, and implementing actions at the public health level.

Accurate and affordable tools for diagnosing anemia and its main determinants are essential for understanding the magnitude and distribution of the problem and the appropriate interventions needed for its timely prevention and treatment. The objective of this review is to address methods, equipment, and sample-related and quality control aspects of hemoglobin measurement for anemia diagnosis. Also, other iron-, infectious-, and genetic-related causes of anemia are addressed in individuals and populations. The best practice for hemoglobin determination is the use of venous blood, analyzed on automated hematology analyzers, with high-quality control measures in place. The importance of a correct anemia diagnosis is highlighted by the cost of a misdiagnosis. A false-negative diagnosis may result in missing out and not treating anemia, its causes, and its adverse effects. On the other hand, a false-positive diagnosis may result in the provision of unneeded treatment or referral for expensive laboratory tests to determine a cause of anemia, wasting valuable resources and risking causing harm. At the individual level, clinicians must understand the causes of absolute and functional anemia to diagnose and treat anemia at the clinical level. Actions toward anemia diagnosis and control at public health levels require global, regional, and country actions that should cover general and context-specific characteristics.

Measurement of food consumption to inform food fortification and other nutrition programs: an introduction to methods and their application.

BACKGROUND: Information on dietary intake is essential for the assessment, planning, monitoring, and evaluation of nutritional interventions. A number of methods are available, each with unique strengths and weaknesses. Dietary intake records, 24-hour recalls, and Food Frequency Questionnaires (FFQs) determine food consumption and nutrient intakes of populations based on individual assessment; few countries have such data at national or regional levels. Food and Agriculture Organization (FAO) Food Balance Sheets (FBS) and food industry data, available in most countries, permit calculations of per capita food consumption but do not provide data on individual consumption. Household Consumption and Expenditures Surveys (HCES) are available for most countries and provide data that can be used to calculate consumption of fortification vehicles and to estimate additional intakes of micronutrients delivered through them to specific population groups. OBJECTIVE: To introduce the reader to the set of papers included in this Supplement reviewing methods and experience with HCES to inform nutrition, and specifically food fortification programs. METHODS: The Monitoring, Assessment, and Data (MAD) working group and colleagues critically reviewed experiences in estimating dietary intakes,focusing on the use of secondary analysis of HCES. RESULTS: HCES predict coverage of the population that consumes a fortification vehicle and consumed amounts of fortification vehicles. HCES allow comparisons of different population strata and may also approximate micronutrient adequacy, based on nutrient density, at the household level. CONCLUSIONS: HCES are useful to inform food fortification and other nutrition programs for planning interventions, but further work is necessary. Currently, combined use of traditional dietary surveys is needed for assessment and for program monitoring and evaluation.

Validation of dietary applications of Household Consumption and Expenditures Surveys (HCES) against a 24-hour recall method in Uganda.

BACKGROUND: The benefits of food fortification depend on the proportion of the population that uses the fortified food (coverage), the amount of the food being consumed, and the additional content of micronutrients in the food. Coverage and amounts consumed can be determined by 24-hour recall or Food Frequency Questionnaires (FFQs). However, these methods are rarely applied. Secondary analysis of data from Household Consumption and Expenditures Surveys (HCES) can be used for these purposes; however, such data analysis has not been validated. OBJECTIVE: To compare the results of HCES and 24-hour recall for estimating the consumption profile of potential fortification vehicles in Uganda. METHODS: Food intake estimates for 24- to 59-month-old children and 15- to 49-year-old women derived from a one-day 24-hour recall carried out in Uganda (Kampala, North, and Southwest) were compared with data from two HCES (2006, nationwide, and 2008, coupled with the 24-hour recall). The analyzed foods were vegetable oil, sugar, wheat flour, maize flour, and rice. RESULTS: Food consumption estimates calculated from HCES may be less accurate than estimates derived by 24-hour recall. Nevertheless, the HCES results are sensitive enough to differentiate consumption patterns among population strata. In Uganda, HCES predicted proportion of the population that consumes the foods, and approximated intakes of main food vehicles by the "observed" consumers (those who reported using the foods), although estimates for the latter were lower for wheat flour and rice. CONCLUSIONS: HCES data offer the basic information needed to provide a rationale for, and help design, food fortification programs. Individual intake surveys are still needed, however, to assess intrahousehold use of foods.

Methods of using household consumption and expenditures survey (HCES) data to estimate the potential nutritional impact of fortified staple foods.

BACKGROUND: Micronutrient malnutrition, caused largely by inadequate dietary intake, is a global public health problem that adversely affects health, child growth and development, work capacity, and quality of life. Mass fortification of widely consumed edible products has the potential to increase micronutrient intakes and thus alleviate some nutritional deficiencies. Although individual-level data about food consumption patterns are ideal for informing the design of food fortification programs, they are often unavailable. Household Consumption and Expenditures Surveys (HCES) are nationally representative cross-sectional surveys conducted over a 12-month period every 2 to 5 years, primarily to characterize household expenditures. OBJECTIVE: We describe how expenditure data from HCES can serve as a proxy for household food consumption and thus aid in choosing which foods to fortify and in determining how much of a micronutrient to add to that food. METHODS: We describe methods of using HCES data to characterize apparent food consumption patterns among different strata within a population. RESULTS: There are several limitations of using HCES data to describe apparent food consumption. HCES do not directly capture information about true food intake, but rather describe food expenditures. We assume that purchased foods are not shared with guests, wasted, fed to animals, gifted, or stockpiled for later use. We also assume that foods are allocated within each household based on energy needs. CONCLUSIONS: Despite the limitations of using HCES data to estimate apparent food consumption, the dearth of individual-level data about food intake renders HCES data useful in designing food fortification programs.

Comparison of estimates of the nutrient density of the diet of women and children in Uganda by Household Consumption and Expenditures Surveys (HCES) and 24-hour recall.

BACKGROUND: Individual dietary intake data are important for informing national nutrition policy but are rarely available. National Household Consumption and Expenditures Surveys (HCES) may be an alternative method, but there is no evidence to assess their relative performance. OBJECTIVE: To compare HCES-based estimates of the nutrient density of foods consumed by Ugandan women (15 to 49 years of age) and children (24 to 59 months of age) with estimates based on 24-hour recall. METHODS: The 52 food items of the Uganda 2006 HCES were matched with nutrient content of foods in a 2008 24-hour recall survey, which were used to refine the HCES-based estimates of nutrient intakes. Two methods were used to match the surveys'food items. Model 1 identified the four or five most commonly consumed foods from the 24-hour recall survey and calculated their unweighted average nutrient contents. Model 2 used the nutrient contents of the single most consumed food from the 24-hour recall. For each model, 14 estimates of nutrient densities of the diet were made and 84 differences were compared. RESULTS: Models 1 and 2 were not significantly different. Of the model 2 HCES-24-hour recall comparisons, 67 (80%) did not find a significant difference. No significant differences were found for protein, fat, fiber, iron, thiamin, riboflavin, and vitamin B6 intakes. HCES overestimated intakes of vitamins C and B12 and underestimated intakes of vitamin A,folate, niacin, calcium, and zinc in at least one of the groups. CONCLUSIONS: The HCES-based estimates are a relatively good proxy for 24-hour recall measures of nutrient density of the diet. Further work is needed to ascertain nutrient adequacy using this method in several countries.

Need for coordinated programs to improve global health by optimizing salt and iodine intake.

High dietary salt is a major cause of increased blood pressure, the leading risk for death worldwide. The World Health Organization (WHO) has recommended that salt intake be less than 5 g/day, a goal that only a small proportion of people achieve. Iodine deficiency can cause cognitive and motor impairment and, if severe, hypothyroidism with serious mental and growth retardation. More than 2 billion people worldwide are at risk of iodine deficiency. Preventing iodine deficiency by using salt fortified with iodine is a major global public health success. Programs to reduce dietary salt are technically compatible with programs to prevent iodine deficiency through salt fortification. However, for populations to fully benefit from optimum intake of salt and iodine, the programs must be integrated. This review summarizes the scientific basis for salt reduction and iodine fortification programs, the compatibility of the programs, and the steps that need to be taken by the WHO, national governments, and nongovernmental organizations to ensure that populations fully benefit from optimal intake of salt and iodine. Specifically, expert groups must be convened to help countries implement integrated programs and context-specific case studies of successfully integrated programs; lessons learned need to be compiled and disseminated. Integrated surveillance programs will be more efficient and will enhance current efforts to optimize intake of iodine and salt. For populations to fully benefit, governments need to place a high priority on integrating these two important public health programs.

Systematic review of studies comparing 24-hour and spot urine collections for estimating population salt intake.

OBJECTIVE: To examine the usefulness of urine sodium (Na) excretion in spot or timed urine samples to estimate population dietary Na intake relative to the gold standard of 24-hour (h) urinary Na. METHODS: An electronic literature search was conducted of MEDLINE (from 1950) and EMBASE (from 1980) as well as the Cochrane Library using the terms "sodium," "salt," and "urine." Full publications of studies that examined 30 or more healthy human subjects with both urinary Na excretion in 24-h urine and one alternative method (spot, overnight, timed) were examined. RESULTS: The review included 1 380 130 participants in 20 studies. The main statistical method for comparing 24-h urine collections with alternative methods was the use of a correlation coefficient. Spot, timed, and overnight urine samples were subject to greater intra-individual and interindividual variability than 24-h urine collections. There was a wide range of correlation coefficients between 24-h urine Na and other methods. Some values were high, suggesting usefulness (up to r = 0.94), while some were low (down to r = 0.17), suggesting a lack of usefulness. The best alternative to collecting 24-h urine (overnight, timed, or spot) was not clear, nor was the biological basis for the variability between 24-h and alternative methods. CONCLUSIONS: There is great interest in replacing 24-h urine Na with easier methods to assess dietary Na. However, whether alternative methods are reliable remains uncertain. More research, including the use of an appropriate study design and statistical testing, is required to determine the usefulness of alternative methods.

Drops of Capillary Blood Are Not Appropriate for Hemoglobin Measurement with Point-of-Care Devices: A Comparative Study Using Drop Capillary, Pooled Capillary, and Venous Blood Samples.

Population-based surveys matched by time but using different methodologies for determining hemoglobin (Hb) concentration have shown inconsistencies in estimating anemia prevalence. This study aimed to estimate measurement errors in Hb quantification in HemoCue 201+ using venous blood (VB) and capillary blood both drops (DCB) and pools (PCB), and compare the results against those of a reference method (VB analyzed in hematology analyzers based on the cyanmethemoglobin method). Children (n = 49), adult females (n = 50), and older adults (n = 50) were randomly allocated to donate VB (4 mL) and either DCB (three drops) or PCB (350 µL). Results in HemoCue were analyzed through Bland Altman and Lyn's concordance against Hb concentration by the reference method. A positive average bias (systematic error) was found for the HemoCue (0.31 g/dL) using the same VB samples. This value was then subtracted from all readings carried out in the device. After this adjustment, DCB still produced a positive bias (0.42 ± 0.81 g/dL), and the variation of single results was ±1.6 g/dL (95% CI). PCB and VB performed similarly; the average bias was negligible (-0.02 ± 0.36 and 0.00 ± 0.33 g/dL, respectively) and the variation of the results (95% CI) was ±0.7 g/dL or lower. Lyn's concordance values were 0.86, 0.96, and 0.98 for DCB, PCB, and VB, respectively. Random variation using DCB is too large to approximate the true Hb values, and therefore DCB should be discontinued for diagnosing anemia both in individuals and in populations.