Prevalence and correlates of anemia among children aged 6-23 months in Wolaita Zone, Southern Ethiopia

Background Anemia, the world’s most common micro-nutrient deficiency disorder, can affect a person at any time and at all stages of life. Though all members of the community may face the problem, children aged 6-23 months are particularly at higher risk. If left untreated, it adversely affects the health, cognitive development, school achievement, and work performance. However, little was investigated among young children in Sub-Saharan countries including Ethiopia. This research aimed to investigate its magnitude and correlates to address the gap and guide design of evidence based intervention. Methods A community-based cross-sectional study was conducted from May -June 2016 in rural districts of Wolaita Zone. Multi-stage sampling technique was applied and 990 mother-child pairs were selected. Socio-demography, health and nutritional characteristics were collected by administering interview questionnaire to mothers/care-givers. Blood samples were taken to diagnose anemia by using HemoCue device, and the status was determined using cut-offs used for children aged 6-59 months. Hemoglobin concentration below 11.0 g/dl was considered anemic. Data were analyzed with Stata V14. Bivariate and multivariable logistic regressions were applied to identify candidates and predictor variables respectively. Statistical significance was determined at p-value < 0.05 at 95% confidence interval. Results The mean hemoglobin level of children was 10.44±1.3g/dl, and 65.7% of them were anemic. Among anemic children, 0.4% were severely anemic (<7.0g/dl), while 28.1% and 37.2% were mildly (10.0-10.9g/dl) and moderately (7.0-9.9g/dl) anemic, respectively. In the multivariable analysis, having maternal age of 35 years and above (AOR = 1.96), being government employee (AOR = 0.29), being merchant (AOR = 0.43) and 'other' occupation (AOR = 3.17) were correlated with anemia in children in rural Wolaita. Similarly, receiving antihelminthic drugs (AOR = 0.39), being female child (AOR = 1.76), consuming poor dietary diversity (AOR = 1.40), and having moderate household food insecurity (AOR = 1.72) were associated with anemia in rural Wolaita. Conclusion A large majority of children in the rural Wolaita were anemic and the need for proven public health interventions such as food diversification, provision of anti-helminthic drugs and ensuring household food security is crucial. In addition, educating women on nutrition and diet diversification, as well as engaging them with alternative sources of income might be interventions in the study area. A community based cross-sectional study was conducted among children aged 6–23 months residing in rural districts of Wolaita Zone, Southern Ethiopia, from May to June 2016. Wolaita Zone is one of the 13 administrative zones of southern region (SNNPR) which has 12 rural and 3 urban districts. The Zone was inhabited by over 1.8 million people in 2016 [13]. Wolaita Sodo, the capital of the Zone, is located at 6° 49' N latitude and 39° 47' E longitude, at an altitude of about 1900 meters above sea level. It is located at 330 km south-west of Addis Ababa, Ethiopia. The zone is characterized by its dense population. The majority (88.3%) of its population reside in rural districts whose major livelihood is agriculture. The major food crops cultivated in the zone are maize, sweet potato, enset (false banana), teff (Eragrostis tef), haricot bean, taro, sorghum, Irish potato, yam and cassava [14]. Multi-stage sampling technique was applied to select mother-child paired study population. Children aged 6–23 months were the source population for the study. Initially, four districts were randomly selected from the 12 rural districts. Damot Gale, Boloso Bombe, Humbo and Sodo Zuria districts were selected as study districts. Then, three kebeles (the lowest administrative unit of Ethiopia consisting of nearly 5000 population) were randomly selected from each of the selected districts, making the total number of kebeles included in the study 12. Finally, the study participants were selected through systematic sampling technique from each of the selected kebeles by probability proportional to size i.e., allocating the sample size with regard to the respective kebeles’ population. The total 993 sample size needed for this study was determined by the formula to estimate a single population proportion based on the following assumptions: 71.2% prevalence of anemia in Sub-Saharan Africa [15], 95% confidence interval, 5% margin of error, and 5% non-response rate and design effect of 3. Data were collected through interviewer administered questionnaire prepared in English and translated into Amharic language). The questionnaire was developed by reviewing guidelines and related literatures [12, 15, 16, 17]. It consisted of demographic characteristics, household wealth indicators and anemia risk factors such as health service utilization, recent illnesses, and dietary practices of both mother and child. Hemoglobin concentration was used to determine anemia status of the study participants by taking finger-prick blood sample. Hemoglobin level was analyzed onsite by using HemoCue device (HemoCueHb 301), and values were adjusted for altitude using the UNICEF/WHO guideline. Anemia status was determined using cut-offs used for children aged 6–59 months. Hemoglobin concentration below 11.0 g/dl was considered anemic, whereas, hemoglobin concentrations of 11.0 g/dl and above were considered normal. Severity of anemia was categorized based on the UNICEF, UNU, WHO guideline as follows: children were categorized as mildly, moderately and severely anemic if their blood hemoglobin concentrations are between 10.0–10.9 g/dl, 7.0–9.9 g/dl and < 7.0 g/dl, respectively. Maternal anemia (hemoglobin concentration below 12 g/dl) was diagnosed with the same procedure and device used for child anemia, followed by adjustment for pregnancy and altitude [16]. A 24-hour dietary recall method was used to assess the dietary practice. The Dietary Diversity Score of children was calculated by asking mothers/caregivers about the food items their children consumed in the past 24 hours preceding the survey. All food items consumed by the children in the last 24 hours preceding the survey were categorized into seven food groups such as (1) grains, roots, and tubers, (2) legumes and nuts, (3) milk and milk products, (4) flesh foods, (5) eggs, (6) vitamin-A rich fruits and vegetables, and (7) other fruits and vegetables. Finally, the food groups consumed by the child were added together to obtain dietary diversity score [17]. Food insecurity was measured by HFIAS (Household Food Insecurity Access Scale) tool developed by FANTA (Food and Nutrition Technical Assistant) project. The tool has nine questions asking household’s about the three domains of food insecurity: feeling uncertainty of food supply, insufficient quality of food, and insufficient food intake and its physical consequences in the last month. The households participating in the study were categorized into four levels of food-security (food secure, mildly food insecure, moderately food insecure and severely food insecure) based on the guideline’s recommendation [18]. Household wealth index was constructed using household asset data through PCA (Principal Component Analysis) based on interview responses adopted from Ethiopian Demographic and Health Survey. The presence or absence of each household items such as plow oxen, table, animal-drawn cart, chair, etc. were asked and their responses were coded as ‘0’ for No and ‘1’ for Yes. Finally, the common factor score for each household was produced for grouping households as lower, middle and higher wealth quantile households [19]. Chronic energy deficiency (malnutrition) was assessed using WHO guideline. The WHO Anthro 2005 software was used to calculate Z-score. MUACZ cut-off- point of negative two (−2) was used to define under-nutrition [20]. Data were entered into Epi-Data software version 1.4.4.0 and analyzed with Stata software version 14 (College Station, Texas). Proportions, means and standard deviations (SD) were used to describe the study population by independent variables and anemia. Bivariate logistic regression was done using thirty independent variables to identify the candidate variables (p-value < 0.25) for multivariable regression. Finally, predictors of anemia were determined using multivariable logistic regression model among the selected eleven candidate variables. Multi co-linearity, interaction and mediation among independent variables were checked based on the assumptions such as tolerance, variance inflation factors (VIF), correlation coefficient of interaction, and others to assure the fitness of logistic regression model. The independent variables used for checking multi co-linearity, interaction and mediation were; age of child, age of mother, religion, occupation, family size, meal frequency of mother, meal frequency of child, initiation of complementary feeding, receiving anti-helminthic drug, sex of child, dietary diversity score of child (DDS) and household food insecurity access scale (HFIAS). The statistical significance was determined at p-value < 0.05 at 95% confidence interval. Interviewers and laboratory technicians were trained for two days prior to data collection. A pilot study was done among 50 children who were selected from areas outside the actual study area. The data collection was regularly supervised by trained supervisors and the investigators. The actual data collection was started after Wolaita Sodo University College of Health Sciences and Medicine approved the study. Local administrative bodies were also communicated about the study and permission was obtained ahead of the study. Finally, informed written consent was obtained from the mothers/caregivers. Children diagnosed with anemia were counseled, and those with hemoglobin concentration below 9.0 g/dl were referred to health facility for further treatment and follow up.