Factors associated with anemia among children 6-59 months in Ethiopia, using Ethiopia Demographic and Health Survey data, 2016

Background Anemia is the most common nutritional problem and a wide spread micronutrient deciency disorder even at global scale. In Ethiopia, child hood anemia is the most prevalent and a serious public health problem. The aim of this study is to assess determinants of anemia among children 6–59 months in Ethiopia, Ethiopia Demographic and Health Survey, 2016. Method This study was based on the 2016 Ethiopian Demographic Health Survey (EDHS).A community-based cross-sectional with a two-stage stratied cluster sampling technique was implemented at national level. Total of 7689 children were included in the analysis. Descriptive, bivariate and multivariable logistic regression analysis was employed. Result


Background
Globally, anemia is the most common nutritional problem and wide spread public health micro-nutrient de ciency disorder that affects more than 2 billion people and according to the world health organization (WHO), it is one of the ten most serious health problems in the world [ 1,2].It affects both developed and developing countries with major consequences on human health as well as social and economic developments [3,4].
Childhood anemia is a condition where a child has insu cient hemoglobin (less than 11 grams per deciliter (g/dL) level to provide adequate oxygen to the body tissues [5].In children, anemia results in low oxygenation of brain tissues, which in turn may lead to impaired cognitive function, growth, psychomotor development, leading to reduced academic achievement and earnings potential in their adulthood life [6].
It can occur at any time and at all stages of the life cycle [7].Even though relevant across the life span, anemia in under-ve children is a special case given its signi cance to supporting a range of morbidities and mortality within this population subset [8].
The global prevalence of anemia among pre-school children according to the WHO database 1993-2005was 47.4% (affecting over 293 million children) [9].Study conducted in sub-Saharan Africa revealed that the prevalence of anemia among 6-59 month children was 59%,ranging from 23.7% in Rwanda to 87.9% in Burkina Faso [10].
In Ethiopia, child hood anemia is a serious public health problem.The trend of anemia among Ethiopian 6-59 months children declined from 54-44% from 2005 to 2011, but increased to 57% in EDHS 2016 [11].
Many researchers have been conducted in Ethiopia to show its magnitude and associated factors.
However, it showed a 30% increase (44-57%) from the preceding EDHS 2011 nding within ve years period and remained the main public health problem in the country.Due to its multi factorial nature, correcting anemia often requires an integrated approach.Identifying and addressing the contributing factors could be an important step in order to design successful intervention strategies at national level.
However, most evidences come from small, unrepresentative samples and there is scarcity of solid and recent information showing the determinant factors of anemia among 6-59 months children at national level.In addition, the overall prevalence of anemia in the EDHS 2016 was 56.6% which never been reported from all previous EDHS reports.Since the prevalence of anemia in this study is the highest from all EDHS reports, further analysis and identi cation of the determinant factors is pivotal for designing appropriate intervention strategies at national level.Therefore, this study was designed to assess the determinants of anemia among children aged 6-59 months in Ethiopia and to inform health authorities at different levels of the government hierarchies on the type of variables to be targeted and type of measures to be taken to prevent and control child hood anemia.Finally, the number of live children 6 to 59 months, with hemoglobin data was considered in the nal data analysis to identify the determinants of anemia among children in Ethiopia.In the 2016 EDHS data set, there were 8603childrenaged 6-59 months, of whom 914children were excluded from the analysis data due to missed hemoglobin data.The total number of 6-59 months children included in the nal analysis were 7689.

Methods
Measurement and operational de nition.
Anemia status was determined based on hemoglobin concentration in blood adjusted to altitude.Anemia was de ned as occurrence of hemoglobin level of less than 11 g/dL.It was further categorized into mild, moderate, and severe anemia with a hemoglobin range of 10-<11 g/dl, 7-<10 g/dl, and < 7 g/dl respectively.

Study Design
Community based cross sectional study design was implemented at national level as one part of the periodic EDHS and we have extracted and analyzed the child hood anemia part from the EDHS2016.

The study population
Randomly selected children aged 6-59 months who have hemoglobin data in their data record in the archive of EDHS 2016 data.

Sampling technique
The 2016 EDHS data is already selected using a strati ed, two stage cluster design, and enumeration areas were the sampling units for the rst stage.In the rst stage, 645 enumeration areas were randomly selected: 202 in urban areas and 443 in rural areas.In the second stage, a xed number of 28 households per cluster were selected randomly for each enumeration areas.Of the 18,008 households were randomly selected and 16,650 (98% of response rate) households were eligible and interviewed.Additional information about the methodology of EDHS 2016 can be accessed in the report of the main ndings of the survey published elsewhere (11).

Variables in the Study
The outcome variable Anemia status of children aged 6 to 59 months.

Covariates Variables
To analyze the determinants of anemic among 6-59 month sold children, a number of sociodemographic, health, and socio economic factors like; maternal and paternal characteristics, childhood characteristics, household characteristics, and environmental conditions were assessed.

Data Analysis
After data were extracted, we have checked or its completeness and consistency and we did preliminary analysis.Weighted analysis was conducted using the same sampling weight given for each region in Ethiopia DHS to reimburse for the unequal probability of selection between the strata(11).Data analysis was carried out using STATA version v.14.Descriptive statistics was done to describe the data like frequencies and percentages.
Anemia status was determined based on hemoglobin concentration in blood adjusted to altitude.Adjusted concentration less than 11 g/dl was considered as anemic.Sample weights were applied to compensate for the unequal probability of selection between the strata, which has also been geographically de ned for non-responses.
We use logistic regression method to identify determinants of anemia.Bivariate analysis was performed to see the crude association of each covariate variables with the outcome variable (anemia status).Those covariate variables with-value less than 0.20 in the bivariate analysis were included in the nal multivariable logistic regression analysis to adjust for confounding and to identify the nal determinant of anemia among 6-59 month sold children.We use the backward logistic regression method during the multivariable logistic regression analysis.Before inclusion of predictors to the nal logistic regression model, the multi-collinearity was checked using VIF < 10/Tolerance > 0.1 for continuous independent variables.The goodness of t of the nal logistic model was tested using Hosmer and lemeshow test at p value of > 0.05.Outcome measures have been indicated by odds ratio with 95% con dence interval.
Finally, covariate variables with P-value of < 0.05 in the multivariable logistic regression model were considered as statistically signi cant variables in the nal logistic model.

Ethical Considerations
The study proposal got ethical approval from Tigray health research institute and formal letter of permission was obtained from measure DHS project website to access the dataset (http://www.measuredhs.com).

Characteristics of study participants
Data on 7689children between the ages of 6-59 months were included in the nal analysis.The mean age of the children was 31.7 with a SD of +/-15.6 (median: 31 months, range: 6 to 59 months).There was uniform distribution of children by age with the lowest proportion of children (11.7%) found in the lowest age group of 5-11months.Ruraland urban representation of 83% and 17%, respectively.Around one fourth of the children 1826 (23.7%) were fourth and fth birth order.The major number of households (45.3%) has two children and more than one-third (35.3%) of households had only one child with in the stated age range (Table 1).
Half of (49.8%) of mothers /caregivers of the children were within the age group of 20-29 years and around two third (65.1%) were Illiterate.More than two-third of the mothers (71.7%) were not currently working.More than one third (36.4%) of households were grouped under poorest rank of wealth index, and one from three mothers (33.2%) did not visit antenatal care during their recent pregnancy (Table 2).
Considering the nutritional status of the children, more than one third (39%) of the children were stunted, around one-quarter (26%) were underweight, and one-in ten (11.4%) were wasted.Nearly half (48.7%) of the children were not received Vitamin A supplementation in last 6 months (Table 3).

Effect of maternal and child factors on anemia among Children Aged6-59 Months
The prevalence of anemia among children was 56.6%(with 22.5%, 30.4%, and 3.7% for mild moderate and severe anemia respectively).Mean hemoglobin concentration was 12.3 ± 1.9 g/lathe prevalence of anemia was slightly higher among males than females with a prevalence of 51.8% and 48.2% respectively (Fig. 1 and Table 1).The highest prevalence was reported in the lowest age range of 6-11 months with a prevalence of 78.2% and it steadily decreased as the age of the children increased.High prevalence of anemia was observed among children above third birth order (58.5%) than less than or equal to third birth order (Fig. 2).Highest prevalence of anemia also reported among mothers who gave rst birth before 20 years (73.5%) and among mothers ageless than 25 years at the time of the survey (64.6%) (Fig. 3).Children with birth interval of less than 24 month and households having 5-6 children have highest anemia prevalence with67.7%,and 82.5%respectively (Fig. 4).

Factors Associated with Anemia among Children Aged 6-59 Months
In the bivariate logistic regression analysis age of child, sex, maternal age, residence, maternal educational status, number of house hold members, sex of house hold head, wealth index, currently living with husband, respondent currently working, birth order of the child, birth status, birth interval, number of ANC visit, deworming during pregnancy, recent diarrhea, vitamin A in last 6months, level of stunting, level of underweight, and level of wasting were signi cantly associated with anemia.
Children of mothers aged 20-29 and 30-39 years were 1.6 times (AOR = 1.64; 95% CI: 1.21, 2.23) and 1.3 times (AOR = 1.29; 95% CI: 1.01, 1.66) respectively more likely to be anemic than children of mothers in the highest age range (40-49 years).Considering wealth index of the households, children born from the poorest households were 1.5(AOR = 1.23; 95% CI: 1.23, 1.95) times more likely to be anemic than children from richest households.Children from mothers not currently living with husband were 1.3 times (AOR = 1.31; 95% CI: 1.02, 1.67) more likely to be anemic than children of mothers currently living with their husband.

Discussion
This study assessed the prevalence and associated factors of anemia among children aged 6 to 59 months in Ethiopia.Anemia in children is a major public health problem and most common causes of child death in Ethiopia [12].The overall prevalence of anemia was 56.6%.Even though high rate of breastfeeding has been reported in Ethiopia, breast milk is poor in iron content.Plant based food is commonly consumed in Ethiopia, which is low in iron content and poor in bioavailability due to phytate and other inhibiter [11].The magnitude of anemia reported in this study showed severe public health problem according to WHO classi cation [13].The present nding is in agreement with those of related studies done in developing countries.This nding was similar to study reported from Uganda58.8%[14] and Bangladesh national representative data 51.9% [15] and higher than study done in Gonder, Ethiopia (28.6%) [16] and Honduran (39%) among children [17].
However, the result of the present study is lower than studies conducted in Togo demographic and health survey 84.6%[18], and Ghana demographic and health survey 78.4% [19].The difference in the prevalence might be due to variation in sample size, socio-demographic status of parents, geographical location, sampling techniques, socioeconomic status and the diet consumed and other associated factors.With an increase in child age, the risk of childhood anemia decreases in all age categories.The similar effect of the age of the child on anemia has been observed in the previous studies [15][16][18][19][20][21].The possible reason for the elevated level of anemia with in younger age children might be low balanced nutritional intakes that may not be su cient to satisfy the relatively higher iron requirement due to rapid growth [22].Additional reason could be, younger children in Ethiopia mostly depends on breast milk, which is poor in iron content and the complementary food is entirely plant based which is poor in bioavailability and rich in absorption inhibiters like phytate.The other possible reason might be the poor infant and young child feeding practices [23] and perhaps childhood physiology was predominant that is children by 6 month of age their Iron stores are generally depleted while the blood volume doubles from 4 to 12 months after birth.Thus, the dietary sources of iron are very important to keep up with this rapid rate of red blood cell synthesis and anemia may result if the dietary sources are inadequate [24][25].
Children born from younger maternal age were high risk of childhood anemia this nding was consistent with the reports [26][27].This might be due to inattention to feed diversi ed foods for their children according to the recommended standard.Stunted and underweight children were more likely to be anemic than their counter parts.This nding is similar to studies conducted elsewhere [15,21,[28][29].This could be due to anemia and under nutrition often have a synergism association in relation to socioeconomic status, sanitation, infections and parasitic diseases and diet in the same individuals [30].
Children from poorest households and illiterate mothers 1.6 times and 1.4 times respectively more likely to develop anemia than their richest counterpart and at higher education rank categories.It is in line with study in Bangladesh and Eastern Amhara, Ethiopia.Children from poor family and food in secure households were at higher risk of developing anemia than their counterparts [15,29,31].In contrary children from the richest and middle-class households had a lower average hemoglobin concentration than those from the poorest households [32].The reason could be, poorest households cannot afford iron rich animal based foods, and may have poor personal hygiene and environmental sanitation which leads to infection and micronutrient mal-absorption.Illiterate mothers lack knowledge on infant and young child feeding practice, and literacy can in turn affect the income earning capacity of mothers and their decision power on spending money.Illiteracy was positively associated with child hood anemia in agreement with previous studies [14,18].This might be because educated mothers have better health and nutrition knowledge and child rearing practices than uneducated ones which contribute to improved child health and anemia status.
Rising children birth order signi cantly associated with child hood anemia in line with study [33][34][35][36].This might be due to distribution of scarce resources within the family and interrelated to maternal exhaustion of micronutrients.Mild maternal iron de ciency and anemia have few signi cant repercussions on the iron status of the newborn but severe anemia does have a strong in uence.

Congested birth interval of children had negatively associated with children anemia this study was in line
with the study conducted in Africa countries and Ethiopia the effect of the preceding birth interval variable on the index child's hemoglobin level was positive and with every increase of one month of the preceding birth interval there is a gain of 0.015 g/l hemoglobin level [37][38][39].This might be due to short birth interval between birth might cause sharing problems among living siblings and parents can't take better care of their children and compromise the breastfeeding duration of the former child [40].The mother herself may be biologically exhausted from too frequent births, and this could also negatively affect the nutritional status and hemoglobin level of the newborn baby as a result of the intergenerational link [41].
Children born from mothers with only one ANC visit were 1.5 times more likely to have anemia than children from mothers with the recommended number of ANC visit (four times and above).Study conducted in Gonder city (Ethiopia) found that home delivery was signi cantly associated with childhood anemia [16].Since maternal anemia is associated with childhood anemia [15] and study conducted in Addis Abeba, Ethiopia indicated no antenatal care visit was signi cantly associated with maternal anemia [42].This could be due to the bene t of the recommended number of ANC visit for early diagnosis and treatment of maternal anemia; maternal folate and iron supplementation; provision of de-worming medication; malaria prevention, diagnosis, and management; and provision of nutrition counseling all of which could have signi cant impact on childhood anemia.Therefore, mothers should attend the recommended number of ANC visit during the entire period of pregnancy to minimize the risk of child hood anemia.

Limitation of the study
The limitation of this study was its cross-sectional design, which does not allow the identi cation of the precedence in time between exposure and outcome (chicken egg dilemma).

Conclusion
The overall prevalence of anemia in this study using a cut off level of hemoglobin < 11 g/dl was 56.6% which never been reported from all previous EDHS reports.Since the prevalence of anemia in this study is the highest from all EDHS reports, strong intervention approach focusing on the identi ed variables should be in place.Child age, maternal age, wealth index of the household, whether mothers live with husband or not, respondent currently working, birth order of the child, birth interval of the child, number of ANC visit, stunting, and underweight were statistically signi cant predictors of childhood anemia.Childhood anemia should be the top priority agenda of the health sector at all health hierarchies, giving more responsibility to the primary health care unit.

Abbreviations
EDHS are periodical survey with ve years interval, sometimes different from ve with special cases.The 2016 EDHS is the fourth and the most recent DHS in Ethiopia, following the 2000, 2005 and 2011 EDHS surveys.The 2016 EDHS was conducted on a nationally representative sample of nine regions and two city administrations of the country.Subdivided into 68 zones, 817 districts and 16,253 kebeles (lowest local administrative units of the nation).

Figures
Figures

Table 2 :
The study proposal got ethical approval from Tigray health research institute and formal letter of permission was obtained from measure DHS project website to access the dataset (http://www.measuredhs.com)House hold characteristics of pregnant mothers, EDHS 2106 (n =3082).

Table : 4
Parameter estimates of related covariates in the final proportional odds model of pregnant mothers, EDHS 2106 (n =3082)