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 (χ 2 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.
Nationally representative data from the Demographic and Health Surveys (DHS) Program for 29 countries in SSA from 2010 to 2019 were acquired for analysis in this study. The DHS Program provides large secondary data gathered from surveys using probability sampling methods, following standard protocols that are internationally accepted. Different sets of questionnaires designed and pretested to ensure reliability and amenability for comparison of data gathered on various spatial and temporal scales are used in the survey. Some questionnaires the Program uses include the ‘children’s questionnaire’ ‘mother’s questionnaire’, ‘men’s questionnaire’ and ‘household questionnaire’. These questionnaires cover a broad range of variables cutting across demographics and anthropometrics, water and sanitation, health, wealth, nutrition among others. The Program recruits and trains field officers to collect accurate data and measurement of weight, height, anaemia using recommended guidelines and instruments. Data on other important variables such as household cooking fuel, urbanicity, wealth, water and sanitation are taken at the household level. The dataset used in this study are: Children’s Data—Children’s Recode, and Household Data—Household Recode (variable names: caseid; v000; v001 v007; v013; v102; v113; v116; v136; v149; v151; v152; v190; bord; b4; b8; m19; hw2; v457; v005; hhid; hv001, hv000; hv226). A sample of 123, 182 was drawn from 29 countries (figure 1) accros the five geographic regions—Western, Eastern, Central and Southern Africa in SSA. For a country to be selected, it must meet the following criteria: should be found in SSA based on the United Nations regional groupings; it must have a DHS dataset with standardised questions and observations on anaemia level of children under 5 years as well as household cooking fuel type, urbanicity, source of drinking water and type of toilet facility. Where multiple datasets exist for a country, the most recent dataset is used. Map of study countries. The dataset provided information on household cooking fuel type, source of drinking water and toilet facility type at the household level. The observations for household cooking fuel were classified into ‘clean’ and ‘unclean’ (polluting fuels) following the criteria used in previous studies25 26 (see table 1). The weight of the child at birth named as ‘birth weight’ was categorised as ‘underweight’ (<2.5 kg) and ‘normal’ (≥2.5 kg) (see Yaya et al27). Also, the observations for the household source of drinking water and type of toilet facility were classified into ‘improved’ and ‘unimproved’ using the revised definitions by the WHO/UNICEF Joint Monitoring Programme report.28 The improved and unimproved drinking water sources and toilet facilities categorisation as described by Armah et al29 are summarised in Table 2. Classification of the source of drinking water and toilet facilities under the WHO/UNICEF Joint Monitoring Programme and cooking fuel Distribution of child anaemia status by predictor variables Anaemia status of children is the outcome variable considered in this study. According to DHS, the anaemia status of living children within the age bracket 0–4 years before the survey night was taken. It has its responses classified into four categories according to the WHO recommendation as (i) ‘not anaemic’ for children with Hb count (g/L) measuring above 110 g/L; (ii) ‘mild anaemia’ for Hb count of 100–109 g/L; (iii) ‘moderate anaemia’ for Hb count between 70 and 99 g/L and (iv) ‘severe anaemia’ for Hb count less than 70 g/L. Children with no observations for anaemia count (not tested) and those whose mothers were not listed in the household questionnaire were excluded. Observations under mild, moderate and severe were combined and recoded as ‘1’ for ‘anaemic’ and observations under not anaemic was recoded as ‘0’ ‘normal’ (see Chandran and Kirby30). This produced the dichotomous outcome variable ‘anaemia status’. The predictor chosen for this study is a composite variable derived from household cooking fuel type and urbanicity. The selection of the predictor variable was based on parsimony, literature review, theoretical relevance as well as practical significance. Household cooking fuel type and urbanicity both had two categories since the former was classified as ‘clean’ and ‘unclean’ and the latter measured as ‘rural’ and ‘urban’ per the DHS. This, therefore, gave four mutually exclusive groups: unclean-urban (households relying on ‘unclean’ cooking fuel and found in urban areas); unclean-rural (households relying on ‘unclean’ cooking fuel and found in rural areas); clean-urban (households using ‘clean’ cooking fuels and found in urban areas) and clean-rural (households using ‘clean’ cooking fuels and found in rural areas). This variable combination technique has been widely applied in previous studies.29 31 Out of the four responses, ‘clean-urban’ was chosen as the reference category in the models. Even though urban residents are commonly exposed to outdoor pollution, emissions from household cooking fuels (indoor pollution) is a major problem to rural residents owing to their relatively high dependence on unclean cooking fuels32 33 This formed the basis for the choice of reference category. There is a plethora of evidence on the independent associations between the type of household cooking fuel and urbanicity with childhood anaemia.14 22 33–35 Even though the UNICEF categorisation of the factors that influence the association between household cooking fuel and child anaemia—proximal, immediate and distal factors serves as a useful framework, for parsimony, practical and theoretical considerations, we categorise independent variables drawn from literature under ‘individual-level characteristics’, ‘household characteristics’ and ‘contextual factors’ (see Nambiema et al4 and Amadu et al36). The individual-level characteristics considered in this study are child age in years (0, 1, 2, 3 and 4); sex of child (male, female); birth order (1, 2, 3 and above); perceived birth size (larger than average, average, smaller than average, don’t know); birth weight (underweight, normal); age of the mother (15–19, 20–24, 25–29, 30–34, 35–39, 40–44, 45–49); body mass index (BMI) of the mother (thin, normal and obese); education (no formal, primary, secondary and tertiary); marital status (never married, married, living with a partner, widowed/divorced/separated); employment status (no, yes); number of antenatal care (ANC) by mother (no, yes); and number of postnatal care (PNC) by mother (no, yes). The relevant household-level factors included in this study are wealth status (poor, middle, rich); household size (‘small’ for those with 1–5 members; ‘medium’ 5–10 members and ‘large’ for more than 10 members); age of household head (‘young-aged adults’ for those age below 35; ‘middle-aged adults’ for those between 35 and 64 years and ‘old-aged adults’ for those 65 years and above); sex of household head (male, female); access to electricity (no, yes); type of toilet facility (improved, unimproved); and source of drinking water (improved, unimproved). Finally, we adjusted for the effect of the contextual factor ‘geographic region’ (Western Africa, Eastern Africa, Central Africa, Southern Africa). Variables in this category of factors relate to the attributes of respondent’s neighbourhood, and opportunities and services that are space-bound.37 38 The Stata V.14.0 MP (Stata Corporation) software was used for the analysis of data. The data were first declared as a survey dataset to prevent potential errors that could arise from the complex survey design using the ‘svyset’ command with the cluster, weighting and strata variables. To understand the distribution of childhood anaemia and the influence of predictive factors on anaemia, descriptive analysis was performed. Using ArcGIS V.10.6, the data were integrated with ESRI Shapefiles to construct a map of the study countries showing the distribution of childhood anaemia. We then determined the associations between the anaemia status of children under five and the relevant predictors using the χ2 test of independence. These relationships were further examined by implementing five multilevel logistic regression models. The first model (model 0) with no independent variable indicated the variance in child anaemia as a result of clustering of the primary sampling units. In model I, only the main predictor variable (urbanicity-type of cooking fuel) was included. Model II adjusted for the individual-level characteristics. The effects of both individual-level and the relevant household-level factors were adjusted in model III. Model IV controlled the individual-level and household-level characteristics, and the contextual-level factors. The Akaike’s Information Criterion was the model comparison metric estimated. Results were presented using adjusted ORs (aORs) at p<0.05 and 95% CIs. Patients and the public were not involved in the design and conduct of this research.