Biofuel smoke and child anemia in 29 developing countries: a multilevel analysis

Exposure to air pollution as a risk factor for anaemia: a global scoping review

Anaemia is an important global health issue with various factors responsible for its occurrence. Though nutritional deficiency is one of the main causes of the disease, evidence suggests a potential link between long-term exposure to ambient air pollution and an increased risk of developing anaemia. Our scoping review evaluates studies conducted across the world to examine possible associations between anaemia and ambient air pollution. Six databases were searched, 153 sources were identified, and 21 articles were included in the review. Apart from one article which showed no significant effect, studies reported positive associations between anaemia and air pollution. This was true for both indoor and outdoor air pollution, various types of particulate matter exposure, and across demographic groups. The review highlights the importance of recognizing exposure to air pollution as a potential risk factor for anaemia and emphasizes the imperative for focused interventions and policy measures to mitigate air pollution.

Association of household air pollution exposure and anemia among pregnant women: Analysis of baseline data from 'Household Air Pollution Intervention Network (HAPIN)' trial

BACKGROUND

Anemia is common in low- and middle-income countries (LMICs), causing significant health issues and social burdens. Exposure to household air pollution from using biomass fuels for cooking and heating has been associated with anemia, but the exposure-response association has not been studied.

OBJECTIVES

We evaluated the associations between personal exposure to air pollution and both hemoglobin levels and anemia prevalence among pregnant women in a multi-country randomized controlled trial.

METHODS

We studied 3,163 pregnant women aged 18-35 years with 9-20 weeks of gestation, recruited as part of the Household Air Pollution Intervention Network (HAPIN) randomized controlled trial in Guatemala, India, Peru, and Rwanda. We assessed 24-hour personal exposures to fine particulate matter (PM2.5), black carbon (BC), and carbon monoxide (CO), and measured hemoglobin levels at baseline (15 ± 3 weeks gestation). Linear and logistic regression models were used to examine the associations of measured pollutants with hemoglobin levels and anemia prevalence, adjusting for confounding.

RESULTS

Single-pollutant models showed associations of CO with higher hemoglobin levels and lower anemia prevalence. Bipollutant models involving CO and PM2.5 also revealed that an interquartile range (IQR) increase in CO concentrations (2.26 ppm) was associated with higher hemoglobin levels [β = 0.04; 95 % confidence interval (CI): 0.01, 0.07], and a lower odds of anemia prevalence [odds ratios (OR) = 0.90; 95 % CI: 0.83, 0.98]. PM2.5 was inversely related to hemoglobin and positively associated with anemia, but results were not statistically significant at the 0.05 alpha level. County-specific results showed that 3 of 4 countries showed a similar association between CO and hemoglobin. We found no association of BC levels with hemoglobin levels or with anemia prevalence.

CONCLUSION

Our findings suggest that exposure to CO is associated with higher hemoglobin and lower anemia prevalence among pregnant women, whereas PM2.5 showed the opposite associations.

Smoke exposure, hemoglobin levels and the prevalence of anemia: a cross-sectional study in urban informal settlement in Southern Ghana

BACKGROUND

In sub-Saharan African cities, more than half of the population lives in informal settlements. These settlements are close to smoky dumpsites, industrial plants, and polluted roads. Furthermore, polluting fuels remain their primary sources of energy for cooking and heating. Despite evidence linking smoke and its components to anaemia, none of these studies were conducted on populations living in urban informal settlements. This study investigated the risks of anemia/mean Haemoglobin (HB) levels in an informal settlement in Accra, Ghana. Exposure to smoke was examined across various sources, encompassing residences, neighborhoods, and workplaces.

METHODS

The study was a facility-based cross-sectional design among residents at Chorkor, an informal settlement in the Greater Accra region of Ghana. A questionnaire was administered at a community hospital during an interview to gather data on sources of smoke exposure in the household, in the neighbourhood, and in the workplace. A phlebotomist collected blood samples from the participants after the interview to assess their anaemia status.

RESULTS

The population (n = 320) had a high prevalence of anemia, with 49.1% of people fitting the WHO's definition of anemia, while the average HB level was 12.6 ± 2.1 g/dL. Anemia was associated with the number of different types of waste burnt simultaneously [(1 or 2: prevalence ratio (PR): 95% confidence interval (CI), 1.14, 0.99-1.28: 3+: 1.16, 1.01-1.63, p-for-trend = 0.0082)], fuel stacking [(mixed stacking: 1.27, 1.07-1.20: dirty stacking:1.65, 1.19-2.25, p-for-trend = 0.0062)], and involvement in fish smoking (1.22, 0.99-1.06). However, the lower limit of the CIs for number of different forms of garbage burned simultaneously and engagement in fish smoking included unity. Reduced mean HB levels were associated with the number of different types of waste burnt simultaneously [(1 or 2: regression coefficient (β): 95% confidence interval (CI), -0.01, -0.97- -0.99: 3+: -0.14, -0.77- -0.05)], current smoker [(yes, almost daily: -1.40, -2.01- -0.79: yes, at least once a month: -1.14, -1.79- -0.48)], Second-Hand-Smoking (SHS) (yes, almost daily: -0.77, -1.30- -0.21), fuel stacking [(mixed stacking-0.93, -1.33-0.21: dirty stacking-1.04, -1.60- -0.48)], any smoke exposure indicator in the neighbourhood (-0.84, -1.43- -0.25), living close to a major road (-0.62, -1.09- -0.49), and fish smoking (-0.41,-0.93- -0.12).

CONCLUSION

Although the cross-sectional design precludes causality, smoke exposure was associated with mean HB levels and anaemia among populations living in informal settlements.

Associations between hemoglobin levels and source-specific exposure to ambient fine particles among children aged <5 years in low- and middle-income countries

OBJECTIVE

We investigated associations between source-specific fine particulate matter (PM2.5) exposure and hemoglobin levels among children in low- and middle-income countries (LMICs).

METHOD

36,675 children aged < 5 years were collected in 11 LMICs during 2017. We associated child hemoglobin with 20 source-specific PM2.5, and calculated changes in hemoglobin that could be attributed to different PM2.5-mixture scenarios, established using real-world data from 88 Asian and African LMICs (AA-LMICs).

RESULTS

Multiple-source analysis revealed PM2.5 produced by solvents (change in hemoglobin for 1-μg/m3 increment in PM2.5: -10.34 g/L, 95% CI -14.88 to -5.91), industrial coal combustion (-0.51 g/L, 95% CI -9.25 to -0.08), road transportation (-0.50 g/L, 95% CI -6.96 to -0.29), or waste handling and disposal (-0.34 g/L, 95% CI -4.38 to -0.23) was significantly associated with a decrease in hemoglobin level. Decreases in hemoglobin attributable to the PM2.5 mixtures were co-determined by the concentrations and their source profiles. The largest PM2.5-related change in hemoglobin was -10.25 g/L (95% CI -15.54 to -5.27) for a mean exposure of 61.01 μg/m3 in India.

CONCLUSION

Association between PM2.5 and a decrease in hemoglobin was affected by variations in PM2.5 source profiles. Source-oriented interventions are warranted to protect children in LMICs from air pollution.

Early-life environmental exposures and anaemia among children under age five in Sub-Saharan Africa: An insight from the Demographic & Health Surveys

BACKGROUND

Reports show that the majority (60%) of children under age five years in Sub-Saharan Africa are anaemic. Studies in the region have mainly focused on the effect of individual, maternal and household socioeconomic status on the prevalence of anaemia. Currently, there is limited understanding of the association between early-life environmental exposures and anaemia among children in Sub-Saharan Africa.

OBJECTIVE

The study examines the association between early-life environmental exposures and anaemia among children under five in Sub-Saharan Africa.

METHODS

The study used health and demographic data from the Demographic and Health Survey (DHS) program and environmental data from NASA's Geospatial Interactive Online Visualization ANd aNalysis Infrastructure (GIOVANNI) and Atmospheric Composition Analysis Group. Three exposure periods were defined for the study, namely: in-utero, post-utero and cumulative life exposures. Multilevel mixed-effect models were used to assess the associations between environmental exposures and anaemia in each exposure period.

RESULTS

The findings show that 63% of children in the study were anaemic. It also reveals that mean PM 2.5 exposure for in-utero (34.93 μgm^-3), post-utero (35.23 μgm^-3) and cumulative exposure (35.08 μgm^-3) were seven times higher than the new air quality guideline WHO recommended. A 10 μgm^-3 increase in in-utero, post-utero and cumulative PM 2.5 exposures was associated with 4% to 5% increase in the prevalence of anaemia among children. A 10ppbv increase in in-utero, post-utero and cumulative carbon monoxide exposures was associated with 1% increase in the prevalence of anaemia among children. The spatial risk distribution maps show that socioeconomic factors modify the spatial risk distribution pattern.

CONCLUSION

The findings of the study suggest that early-life exposure to ambient air pollution is significantly associated with anaemia among children in Sub-Saharan Africa. Thus, policies aimed at addressing air quality should be incorporated into targeted interventions for anaemia among children in the region.

Risk of anaemia among women engaged in biomass-based fish smoking as their primary livelihood in the central region of Ghana: a comparative cross-sectional study

BACKGROUND

Fish smoking using biomass fuel is an important livelihood for women living in the coastal regions of Ghana and may contribute to anaemia risk. We assessed whether women who smoke fish as their primary livelihood are at increased risk of anaemia compared to women in other livelihoods in the Central Region of Ghana.

METHODS

We conducted a comparative cross-sectional study of 330 randomly selected adult women (18-49 years) whose primary livelihood was either fish smoking (FSL) involving the burning of biomass fuel (n = 175) or other livelihoods (OL) not involving burning of firewood (n = 155). Data on participants' recent diet were collected from a single, quantitative 24-h dietary recall and qualitative 7-day food frequency questionnaire of animal-source food (ASF) consumption. We further assessed participants' haemoglobin concentration using the Urit 12 Hemocue system. We compared total iron intakes, the proportion of dietary iron from animal and plant sources, mean haemoglobin concentrations, and anaemia prevalence between FSL and OL women.

RESULTS

Fish was the most frequently consumed ASF by both groups of women. Although OL women consumed more diverse ASFs in the past week compared with the FSL women (3.4 ± 1.2 vs. 2.7 ± 1.3; p < 0.001), the contribution of ASFs to total iron intake in the past day was greater for the FSL women (49.5% vs. 44.0%; p = 0.030). Estimated total dietary iron intake in the past day was generally low (5.2 ± 4.7 mg) and did not differ by group. The unadjusted prevalence of anaemia was 32 and 27.1% among the FSL and OL women, respectively (p = 0.33). After covariates adjustment, the FSL women had statistically higher anaemia prevalence (36.4% vs. 20.5%; p = 0.032) and 80% greater risk of being anemic (RR: 1.8; 95% CI: 1.1, 3.0) than the OL women.

CONCLUSION

Women who use biomass fuel to smoke fish as their primary livelihood had an increased risk of anaemia. Furthermore, the average 24-h dietary iron intake among both the FSL and OL women was below their daily iron requirement. Interventions to enhance women's dietary iron intake and reduce their livelihood related biomass smoke exposure may be warranted in this population.

Health impacts of indoor air pollution from household solid fuel on children and women

The inefficient and incomplete combustion of solid fuel (SF) is associated with high levels of indoor air pollutants leading to 3.55 million deaths annually. The risk is higher in women and children, due to their higher exposure duration and unique physical properties. The current article aims to provide a critical overview regarding the use of solid fuel, its associated pollutants, their toxicity mechanisms and, most importantly the associated health impacts, especially in women and children. Pollutants associated with SF mostly include polycyclic aromatic hydrocarbons, particulate matter, nitrous oxide, carbon monoxide and sulfur dioxide, and their concentrations are two- to threefold higher in indoor environments. These pollutants can lead to a variety of health risks by inducing different toxicity mechanisms, such as oxidative stress, DNA methylation, and gene activation. Exposed children have an increased prevalence of low birth weight, acute lower respiratory tract infections, anemia and premature mortality. On the other hand, lung cancer, chronic obstructive pulmonary disease and cardiovascular diseases are the major causes of disability and premature death in women. Indoor air pollution resulting from SF combustion is a major public health threat globally. To reduce the risks, it is important to identify future research gaps and implement effective interventions and policies.

Energy, Data, and Decision-Making: a Scoping Review-the 3D Commission

Access to energy is an important social determinant of health, and expanding the availability of affordable, clean energy is one of the Sustainable Development Goals. It has been argued that climate mitigation policies can, if well-designed in response to contextual factors, also achieve environmental, economic, and social progress, but otherwise pose risks to economic inequity generally and health inequity specifically. Decisions around such policies are hampered by data gaps, particularly in low- and middle-income countries (LMICs) and among vulnerable populations in high-income countries (HICs). The rise of "big data" offers the potential to address some of these gaps. This scoping review sought to explore the literature linking energy, big data, health, and decision-making.Literature searches in PubMed, Embase, and Web of Science were conducted. English language articles up to April 1, 2020, were included. Pre-agreed study characteristics including geographic location, data collected, and study design were extracted and presented descriptively, and a qualitative thematic analysis was performed on the articles using NVivo.Thirty-nine articles fulfilled eligibility criteria. These included a combination of review articles and research articles using primary or secondary data sources. The articles described health and economic effects of a wide range of energy types and uses, and attempted to model effects of a range of technological and policy innovations, in a variety of geographic contexts. Key themes identified in our analysis included the link between energy consumption and economic development, the role of inequality in understanding and predicting harms and benefits associated with energy production and use, the lack of available data on LMICs in general, and on the local contexts within them in particular. Examples of using "big data," and areas in which the articles themselves described challenges with data limitations, were identified.The findings of this scoping review demonstrate the challenges decision-makers face in achieving energy efficiency gains and reducing emissions, while avoiding the exacerbation of existing inequities. Understanding how to maximize gains in energy efficiency and uptake of new technologies requires a deeper understanding of how work and life is shaped by socioeconomic inequalities between and within countries. This is particularly the case for LMICs and in local contexts where few data are currently available, and for whom existing evidence may not be directly applicable. Big data approaches may offer some value in tracking the uptake of new approaches, provide greater data granularity, and help compensate for evidence gaps in low resource settings.

Household cooking fuel type and childhood anaemia in sub-Saharan Africa: analysis of cross-sectional surveys of 123, 186 children from 29 countries

OBJECTIVE

This study sought to investigate the joint effect of household cooking fuel type and urbanicity (rural-urban residency) on anaemia among children under the age of five in sub-Saharan Africa.

DESIGN

We analysed cross-sectional data of 123, 186 children under the age of five from 29 sub-Saharan African countries gathered between 2010 and 2019 by the Demographic and Health Survey programme. Bivariate (χ² test of independence) and multilevel logistic regression were used to examine the effect of urbanicity-household cooking fuel type on childhood anaemia. Results were reported as adjusted odds ratios (aORs) with 95% CIs at p<0.05.

OUTCOME MEASURES

Anaemia status of children.

RESULTS

More than half (64%) of children had anaemia. The percentage of children who suffered from anaemia was high in those born to mothers in Western Africa (75%) and low among those born in Southern Africa (54%). Children from rural households that depend on unclean cooking fuels (aOR=1.120; 95% CI 1.033 to 1.214) and rural households that depend on clean cooking fuels (aOR=1.256; 95% CI 1.080 to 1.460) were more likely to be anaemic as compared with children from urban households using clean cooking fuel. Child's age, sex of child, birth order, perceived birth size, age of mother, body mass index of mother, education, marital status, employment status, antenatal care, wealth quintile, household size, access to electricity, type of toilet facility, source of drinking water and geographic region had significant associations with childhood anaemia status.

CONCLUSIONS

Our study has established a joint effect of type of household cooking fuel and urbanicity on anaemia among children under the age of five in sub-Saharan Africa. It is therefore critical to promote the usage of clean cooking fuels among households and women in rural areas. These should be done taking into consideration the significant child, maternal, household, and contextual factors identified in this study.

Perceptions and beliefs about anaemia: A qualitative study in three agroecological regions of Ghana

Little evidence exists concerning perceptions of anaemia in Ghanaian communities, which limits understanding of how to potentially improve health in settings with high anaemia prevalence. We explored lay perceptions of anaemia to understand local knowledge and beliefs and to provide an opportunity to inform interventions. A cross-sectional, qualitative study was conducted in selected communities in three regions of Ghana with high prevalence of anaemia. Forty-eight focus group discussions (FGDs) were conducted with adolescent girls, adult women of reproductive age and adult men (16 FGDs for each demographic group). Participants across the three demographic groups generally described anaemia as inadequate blood in the body and reported that poor diet, heat, alcohol intake, physiological factors and diseases such as malaria were the main causes of anaemia. Consequences of anaemia mentioned in the FGDs included dizziness, weight loss, loss of appetite and weakness. Prevention of anaemia was perceived to result from improved diet, avoidance of exposure to heat and improved sanitation to avoid diseases. The findings suggest that despite areas of convergence between lay and biomedical knowledge on the causes, consequences and prevention of anaemia, the burden of anaemia remains high in the study regions. This highlights a disconnect between local knowledge of anaemia and the health and nutrition behaviours needed to reduce its incidence. Effective interventions can be developed with and for communities that build upon existing knowledge while filling remaining knowledge gaps or misconceptions.

A Systematic Review and Appraisal of Epidemiological Studies on Household Fuel Use and Its Health Effects Using Demographic and Health Surveys

The domestic combustion of polluting fuels is associated with an estimated 3 million premature deaths each year and contributes to climate change. In many low- and middle-income countries (LMICs), valid and representative estimates of people exposed to household air pollution (HAP) are scarce. The Demographic and Health Survey (DHS) is an important and consistent source of data on household fuel use for cooking and has facilitated studies of health effects. However, the body of research based on DHS data has not been systematically identified, nor its strengths and limitations critically assessed as a whole. We aimed to systematically review epidemiological studies using DHS data that considered cooking fuel type as the main exposure, including the assessment of the extent and key drivers of bias. Following PRISMA guidelines, we searched PubMed, Web of Science, Scopus and the DHS publication portal. We assessed the quality and risk of bias (RoB) of studies using a novel tool. Of 2748 records remaining after removing duplicates, 63 were read in full. A total of 45 out of 63 studies were included in our review, spanning 11 different health outcomes and representing 50 unique analyses. In total, 41 of 45 (91%) studies analysed health outcomes in children <5 years of age, including respiratory infections (n = 17), death (all-cause) (n = 14), low birthweight (n = 5), stunting and anaemia (n = 5). Inconsistencies were observed between studies in how cooking fuels were classified into relatively high- and low-polluting. Overall, 36/50 (80%) studies reported statistically significant adverse associations between polluting fuels and health outcomes. In total, 18/50 (36%) of the analyses were scored as having moderate RoB, while 16/50 (32%) analyses were scored as having serious or critical RoB. Although HAP exposure assessment is not the main focus of the DHS, it is the main, often only, source of information in many LMICs. An appreciable proportion of studies using it to analyse the association between cooking fuel use and health have potential for high RoB, mostly related to confounder control, exposure assessment and misclassification, and outcome ascertainment. Based on our findings, we provide some suggestions for ways in which revising the information collected by the DHS could make it even more amenable to studies of household fuel use and health, and reduce the RoB, without being onerous to collect and analyse.

The Association Between Ambient PM2.5 Exposure and Anemia Outcomes Among Children Under Five Years of Age in India

Anemia is highly prevalent in India, especially in children. Exposure to ambient fine particulate matter (PM2.5) is a potential risk factor for anemia via. systemic inflammation. Using health data from the National Family and Health Survey 2015-2016, we examined the association between ambient PM2.5 exposure and anemia in children under five across India through district-level ecological and individual-level analyses.

METHODS

The ecological analysis assessed average hemoglobin levels and anemia prevalence (hemoglobin < 11 g/dL considered anemic) by district using multiple linear regression models. The individual-level analysis assessed average individual hemoglobin level and anemia status (yes/no) using generalized linear mixed models to account for clustering by district. Ambient PM2.5 exposure data were derived from the Multiangle Imaging SpectroRadiometer (MISR) level 2 aerosol optical depth (AOD) data and averaged from birth date to date of interview.

RESULTS

The district-level ecological analysis found that, for every 10 μg m-3 increase in ambient PM2.5 exposure, average anemia prevalence increased by 1.90% (95% CI = 1.43, 2.36) and average hemoglobin decreased by 0.07 g/dL (95% CI = 0.09, 0.05). At the individual level, for every 10 μg m-3 increase in ambient PM2.5 exposure, average hemoglobin decreased by 0.14 g/dL (95% CI = 0.12, 0.16). The odds ratio associated with a 10-μg m-3 increase in ambient PM2.5 exposure was 1.09 (95% CI = 1.06, 1.11). There was evidence of effect modification by wealth index, maternal anemia status, and child BMI.

CONCLUSION

Our results suggest that ambient PM2.5 exposure could be linked to anemia in Indian children, although additional research on the underlying biologic mechanisms is needed. Future studies on this association should specifically consider interactions with dietary iron deficiency, maternal anemia status, and child BMI.Keywords: Anemia; Children; Ambient PM2.5 exposure; India; Association.

Cooking, smoking, and stunting: Effects of household air pollution sources on childhood growth in India

This paper investigates the effects of household air pollution (HAP) on child stunting in India using a sample of 206, 898 under-five children from the latest National Family Health Survey (2015-16). Descriptive statistics and multivariate analysis were used to understand the association of stunting by type of cooking fuel, separate kitchen, and indoor smoking in the household. Using clean cooking fuels (CCFs), having a separate kitchen, and being unexposed to smoking can reduce the prevalence of stunting by 4%, 1%, and 1%, respectively, from the current prevalence of stunting (38%). The probability of childhood stunting among children living in households using unclean cooking fuel (UCF) was significantly higher (OR-1.16; 95% CI: 1.13-1.19) than those living in households using CCF. Findings were similar results in the absence of separate kitchen (OR-1.08; 95% CI: 1.05-1.10) and exposure to environmental tobacco smoke (OR-1.06; 95% CI: 1.04-1.08). Households using UCF had a 16% higher likelihood of stunting, while there was a strong gradient of HAP with stunting after controlling socioeconomic and demographic factors. Therefore, the LPG programs, such as the Pradhan Mantri Ujjwala Yojana, may be crucial to reduce HAP and its adverse impact on stunting, and successively to achieve sustainable development goals.

Risk factors of anemia amongst elderly population living at high-altitude region of India

Introduction:

Anemia is a major public health problem amongst elderly population in India. Anemia in old age further worsens the age-related decline in functional ability, mobility, fatigue, bone density, and skeletal muscle mass. There is lack of evidence on the prevalence and risk factors of anemia among elderly population. Hence, this study was undertaken.

Methodology:

A community-based cross-sectional study was conducted during the year 2015–2016 in District Nainital, Uttarakhand state, India. A total of 958 subjects were selected from 30 clusters (villages) identified using population proportional to size methodology. Information on sociodemographic profile, nutritional status, body mass index, and dietary intake was obtained. Blood sample was collected from each subject on the filter paper for estimation of hemoglobin (Hb) level using cyanmethemoglobin method.

Results:

We found that 92.1% of the elderly subjects were anemic. Moderate and severe anemia was found to be significantly higher among female subjects, unemployed, illiterates, subjects using smoke-producing fuel, subjects belonging to lower socioeconomic status, malnourished and underweight subjects, subjects with self-reported hyperacidity, and subjects who had not utilized health facility and had lower iron and vitamin C intake when compared with subjects with mild anemia and normal hemoglobin levels.

Conclusion:

High prevalence of anemia exists amongst elderly subjects living at high-altitude region of rural Uttarakhand State, India. There is a need to educate the elderly population about the importance of adequate intake of foods rich in iron and vitamin C to reduce the prevalence of anemia among them.

Maternal anemia is a potential risk factor for anemia in children aged 6-59 months in Southern Africa: a multilevel analysis

BACKGROUND

The effect of maternal anemia on childhood hemoglobin status has received little attention. Thus, we examined the potential association between maternal anemia and childhood anemia (aged 6-59 months) from selected Southern Africa countries.

METHODS

A cross-sectional study using nationally representative samples of children aged 6-59 months from the 2010 Malawi, 2011 Mozambique, 2013 Namibia, and 2010-11 Zimbabwe demographic and health surveys (DHS) was conducted. Generalized linear mixed models (GLMMs) were constructed to test the associations between maternal anemia and childhood anemia, controlling for individual and community sociodemographic covariates.

RESULTS

The GLMMs showed that anemic mothers had increased odds of having an anemic child in all four countries; adjusted odds ratio (aOR = 1.69 and 95% confidence interval [CI]:1.37-2.13) in Malawi, (aOR = 1.71; 95% CI: 1.37-2.13) in Mozambique, (aOR = 1.55; 95% CI: 1.08-2.22) in Namibia, and (aOR = 1.52; 95% CI: 1.25-1.84) in Zimbabwe. Furthermore, the odds of having an anemic child was higher in communities with a low percentage of anemic mothers (aOR = 1.52; 95% CI: 1.19-1.94) in Mozambique.

CONCLUSIONS

Despite the long-standing efforts to combat childhood anemia, the burden of this condition is still rampant and remains a significant problem in Southern Africa. Thus, public health strategies aimed at reducing childhood anemia should focus more on addressing infections, and micronutrient deficiencies both at individual and community levels in Southern Africa.

Caesarean delivery and anaemia risk in children in 45 low- and middle-income countries

Caesarean delivery (CD) may reduce placental transfusion and cause poor iron-related haematological indices in the neonate. We aimed to explore the association between CD and anaemia in children aged <5 years utilising data from Demographic and Health Surveys conducted between 2005 and 2015 in 45 low- and middle-income countries (N = 132,877). We defined anaemia categories based on haemoglobin levels, analysed each country's data separately using propensity-score weighting, pooled the country-specific odds ratios (ORs) using random effects meta-analysis, and performed meta-regression to determine whether the association between CD and anaemia varies by national CD rate, anaemia prevalence, and gross national income. Individual-level CD was not associated with any anaemia (OR 0.95, 95% confidence interval (CI) [0.86, 1.06]; I²  = 40.2%), mild anaemia (OR 0.91, 95% CI [0.81, 1.02]; I²  = 24.8%), and moderate/severe anaemia (OR 0.97, 95% CI [0.85, 1.11]; I²  = 47.7%). CD tended to be positively associated with moderate/severe anaemia in upper middle-income countries and negatively associated with mild anaemia in lower middle-income countries; however, meta-regression did not detect any variation in the association between anaemia and CD by the level of income, CD rate, and anaemia prevalence. In conclusion, there was no evidence for an association between CD and anaemia in children younger than 5 years in low- and middle-income countries. Our conclusions were consistent when we looked at only countries with CD rate >15% with data stratified by individual-level wealth status and type of health facility of birth.

Solid fuel use is associated with anemia in children

Over 3 billion people use solid fuels as a means of energy and heating source, and ~ 50% of households burn them in inefficient, poorly ventilated stoves. In 2010, ~ 43% of the 640 million preschool children in 220 countries suffered from a certain degree of anemia, with iron deficiency as the main cause in developed countries whereas its causes remained multifactorial in the undeveloped group. In this study, we explore the relations of country-wide variables that might affect the people's health status (from socioeconomic status to more specific variables such as water access). We found independent relationship between solid fuel use and anemia in children under five years old (p < 0.0001), taking into account the prevalence of anemia in pregnant woman and the access to improved water sources. Countries in which the population uses solid fuel the most have over three times higher anemia rates in children than countries with the lowest prevalence of solid fuels use. There is still a complex relationship between solid fuels use and anemia, as reflected in its worldwide significance (p < 0.05) controlled for measles immunization, tobacco consumption, anemia in pregnant mothers, girl's primary education, life expectancy and improved water access but not (p > 0.05) when weighing for sanitation access or income per capita.

Prenatal anemia control and anemia in children aged 6-23 months in sub-Saharan Africa

It is unclear whether routine prenatal anemia control interventions can reduce anemia risk in young children. This study examines the associations between prenatal iron supplementation and/or deworming and anemia in children aged 6-23 months in sub-Saharan Africa (SSA). We analyzed data from Demographic and Health Surveys conducted between 2003 and 2014 in 25 SSA countries. The surveys collected data on prenatal iron supplementation and deworming and determined children's hemoglobin levels through blood testing. We assessed the associations between prenatal iron supplementation and/or deworming and anemia using multinomial logistic regression. The study included 31,815 mother-child pairs: 25.0%, 41.4%, and 4.8% of children had mild, moderate, and severe anemia, respectively. Compared with children whose mothers did not take iron and deworming drugs prenatally, the risk of moderate/severe anemia was reduced among children whose mothers took only iron supplements for ≥6 months (odds ratio [OR]: 0.58; 95% confidence interval [CI]: 0.45-0.76); only deworming drugs (OR: 0.73; 95% CI: 0.56-0.93); deworming drugs plus iron for <6 months (OR: 0.79; 95% CI: 0.67-0.93); and deworming drugs plus iron for ≥6 months (OR: 0.77; 95% CI: 0.59-0.99). Prenatal use of only iron for <6 months was not associated with moderate/severe anemia. Prenatal iron and/or deworming drugs had no effect on mild anemia. Prenatal anemia control interventions are associated with reduced risk of moderate/severe anemia but not with mild anemia in young children in SSA. Iron supplements should be taken for ≥6 months or with deworming drugs prenatally to reduce moderate/severe anemia risk in children.

Does smoke from biomass fuel contribute to anemia in pregnant women in Nagpur, India? A cross-sectional study

BACKGROUND

Anemia affects upwards of 50% of pregnant women in developing countries and is associated with adverse outcomes for mother and child. We hypothesized that exposure to smoke from biomass fuel--which is widely used for household energy needs in resource-limited settings--could exacerbate anemia in pregnancy, possibly as a result of systemic inflammation.

OBJECTIVE

To evaluate whether exposure to smoke from biomass fuel (wood, straw, crop residues, or dung) as opposed to clean fuel (electricity, liquefied petroleum gas, natural gas, or biogas) is an independent risk factor for anemia in pregnancy, classified by severity.

METHODS

A secondary analysis was performed using data collected from a rural pregnancy cohort (N = 12,782) in Nagpur, India in 2011-2013 as part of the NIH-funded Maternal and Newborn Health Registry Study. Multinomial logistic regression was used to estimate the effect of biomass fuel vs. clean fuel use on anemia in pregnancy, controlling for maternal age, body mass index, education level, exposure to household tobacco smoke, parity, trimester when hemoglobin was measured, and receipt of prenatal iron and folate supplements.

RESULTS

The prevalence of any anemia (hemoglobin < 11 g/dl) was 93% in biomass fuel users and 88% in clean fuel users. Moderate-to-severe anemia (hemoglobin < 10 g/dl) occurred in 53% and 40% of the women, respectively. Multinomial logistic regression showed higher relative risks of mild anemia in pregnancy (hemoglobin 10-11 g/dl; RRR = 1.38, 95% CI = 1.19-1.61) and of moderate-to-severe anemia in pregnancy (RRR = 1.79, 95% CI = 1.53-2.09) in biomass fuel vs. clean fuel users, after adjusting for covariates.

CONCLUSION

In our study population, exposure to biomass smoke was associated with higher risks of mild and moderate-to-severe anemia in pregnancy, independent of covariates.

TRIAL REGISTRATION

ClinicalTrials.gov NCT 01073475.

A meta-analysis of pica and micronutrient status

OBJECTIVES

Pica is the craving for and consumption of nonfood items, including the ingestion of earth (geophagy), raw starch (amylophagy), and ice (pagophagy). Pica has long been associated with micronutrient deficiencies, but the strength of this relationship is unclear. We aimed to evaluate the association between pica behavior and the risk of being anemic or having low hemoglobin (Hb), hematocrit (Hct), or plasma zinc (Zn) concentrations.

METHODS

We systematically reviewed studies in which micronutrient levels were reported by pica status. We calculated the pooled odds ratio for anemia or weighted mean difference in Hb, Hct, or Zn concentrations between groups practicing or not practicing pica behaviors.

RESULTS

Forty-three studies including 6,407 individuals with pica behaviors and 10,277 controls were identified. Pica was associated with 2.35 times greater odds of anemia (95% CI: 1.94-2.85, P < 0.001), lower Hb concentration (-0.65 g/dl, 95% CI: -0.83 to -0.48 g/dl, P < 0.001), lower Hct concentration (-1.15%, 95% CI: -1.61 to -0.70%, P < 0.001), and lower Zn concentration (-34.3 μg/dl, 95% CI: -59.58 to -9.02 μg/dl, P = 0.008). Statistical significance persisted after excluding outliers and in subgroup analyses by pica type and life stage.

CONCLUSION

Pica is significantly associated with increased risk for anemia and low Hb, Hct, and plasma Zn. Although the direction of the causal relationship between pica and micronutrient deficiency is unknown, the magnitude of these relationships is comparable to other well-recognized causes of micronutrient deficiencies. Pica warrants greater public health attention; specifically the potential physiological mechanisms underpinning the relationship between pica and micronutrient deficiencies merit further study.

Multi-country health surveys: are the analyses misleading?

BACKGROUND

The aim of this paper was to review the types of approaches currently utilized in the analysis of multi-country survey data, specifically focusing on design and modeling issues with a focus on analyses of significant multi-country surveys published in 2010.

METHODS

A systematic search strategy was used to identify the 10 multi-country surveys and the articles published from them in 2010. The surveys were selected to reflect diverse topics and foci; and provide an insight into analytic approaches across research themes. The search identified 159 articles appropriate for full text review and data extraction.

RESULTS

The analyses adopted in the multi-country surveys can be broadly classified as: univariate/bivariate analyses, and multivariate/multivariable analyses. Multivariate/multivariable analyses may be further divided into design- and model-based analyses. Of the 159 articles reviewed, 129 articles used model-based analysis, 30 articles used design-based analyses. Similar patterns could be seen in all the individual surveys.

CONCLUSION

While there is general agreement among survey statisticians that complex surveys are most appropriately analyzed using design-based analyses, most researchers continued to use the more common model-based approaches. Recent developments in design-based multi-level analysis may be one approach to include all the survey design characteristics. This is a relatively new area, however, and there remains statistical, as well as applied analytic research required. An important limitation of this study relates to the selection of the surveys used and the choice of year for the analysis, i.e., year 2010 only. There is, however, no strong reason to believe that analytic strategies have changed radically in the past few years, and 2010 provides a credible snapshot of current practice.

Demographic and health surveys: a profile

Demographic and Health Surveys (DHS) are comparable nationally representative household surveys that have been conducted in more than 85 countries worldwide since 1984. The DHS were initially designed to expand on demographic, fertility and family planning data collected in the World Fertility Surveys and Contraceptive Prevalence Surveys, and continue to provide an important resource for the monitoring of vital statistics and population health indicators in low- and middle-income countries. The DHS collect a wide range of objective and self-reported data with a strong focus on indicators of fertility, reproductive health, maternal and child health, mortality, nutrition and self-reported health behaviours among adults. Key advantages of the DHS include high response rates, national coverage, high quality interviewer training, standardized data collection procedures across countries and consistent content over time, allowing comparability across populations cross-sectionally and over time. Data from DHS facilitate epidemiological research focused on monitoring of prevalence, trends and inequalities. A variety of robust observational data analysis methods have been used, including cross-sectional designs, repeated cross-sectional designs, spatial and multilevel analyses, intra-household designs and cross-comparative analyses. In this profile, we present an overview of the DHS along with an introduction to the potential scope for these data in contributing to the field of micro- and macro-epidemiology. DHS datasets are available for researchers through MEASURE DHS at www.measuredhs.com.