Inequalities in Stunting Prevalence Among Children Under Age 5 in Ghana Between 1998 and 2014


 BackgroundOver the years, Ghana has made significant improvements in the nutritional status of children, particularly concerning stunting. Though these improvements are commendable, there are concerns of inequalities in the prevalence of stunting among children under five. To this end, we examined the trends and inequalities in the determinants of stunting prevalence in children under five in Ghana, throughout 1998-2014.MethodsUsing the World Health Organization’s (WHO) Health Equity Assessment Toolkit (HEAT) software, we analysed data from the 1998-2014 Ghana Demographic and Health Surveys (GDHS). We approached the inequality analysis in two steps. First, we disaggregated stunting prevalence among children < 5 years by five equity stratifiers: wealth index, education, sex, residence, and region. Second, we measured the inequality through summary measures, namely Difference, Population Attributable Risk, Ratio, and Population Attributable Fraction. A 95% confidence interval was constructed for point estimates to measure statistical significance.ResultsConcerning economic status, only the simple summary measures (Difference [D], Ratio [R]) showed significant inequality in stunting. For instance, both D (23.40; 17.55-29.25) and R (2.43; 1.78-3.09) revealed substantial economic variation in stunting in 1998 and the same trend was noted across all the survey years. The complex summary measures, however, showed a significant but negative association. Both D (16.36; 12.13-20.60) and R (1.90; 1.51-2.28) revealed a positive significant disparity in favour of urban residents in 1998. The simple measures further indicated a significant disparity in stunting at the detriment of male children throughout the period studied. Finally, a significant disparity at the expense of children in the Northern Region was evident in 1998 (D=31.00; R=3.22), 2003 (D=37.21; R=3.17) and 2014 (D=22.73; R=3.19).ConclusionInequalities in stunting prevalence in Ghana is to the disadvantaged children of poorest wealth quintile, mothers with no formal education, male children, rural residents and the Northern Region of Ghana. We recommend the introduction and strengthening of equitable interventions focusing on nutrition on sub-populations in the country who suffer from a higher burden of stunting.


Conclusion
Inequalities in stunting prevalence in Ghana is to the disadvantaged children of poorest wealth quintile, mothers with no formal education, male children, rural residents and the Northern Region of Ghana. We recommend the introduction and strengthening of equitable interventions focusing on nutrition on sub-populations in the country who suffer from a higher burden of stunting.

Background
The nutritional status of children under ve years is an important element that affects their overall health and wellbeing. Children under ve sometimes suffer from undernutrition which manifests in three ways: wasting, underweight, and stunting [1]. Stunting has become a signi cant anthropometric measure for children's socio-economic deprivation [2]. The term "stunting" is also referred to as linear growth retardation [3], suggesting that a stunted child is one who is too short for his/her age [4]. Globally, there are more than 165 million stunted children, with low-and middle-income countries hosting the biggest burden of stunting [5]. In Ghana, there was a decline in stunting from 28% in 2008 to 19% in 2014. Despite this, stunting remains high in children under ve years in Ghana [6], with signi cant regional variations [7].
Extant literature has associated stunting among children to several factors, including insu cient nutritional intake or malnutrition, infectious diseases, and poor socioeconomic status [4,8]. Other studies have also identi ed low birth weight, recurrent infection, nutritional de ciencies/inadequacies, and insu cient care to be contributory factors to stunting among children. There is also evidence to show that one-fth of all stunting originated at conception [9,10,11]. Furthermore, the existing body of knowledge shows that stunting perpetuates inequalities and has the tendency to exacerbate poverty and result in poor academic performance and high fertility [12]. Therefore, it is critical to invest in interventions to ameliorate stunting among children [13].
The United Nations, in its attempt to improve children's health, placed premium on issues related to stunting in the then Millennium Development Goals and the current Sustainable Development Goals (SDGs) as a matter of policy to propel countries, particularly LMICs, to combat stunting. In relation to this, Ghana has implemented policies such as capitation grant and school feeding programme to help reduce the levels of food insecurity, malnutrition, and stunting among children [14]. While the implementation of such policies is a step in the right direction, there is still a need for evidence-based stunting inequalities studies, as such studies are an exemplary step in identifying priority areas necessary for interventions design and effective implementation. To this end, we examined the trends in stunting prevalence in children under ve in Ghana, throughout 1998-2014.

Data source
Data used for this study emerged from the 1998, 2003, 2008, and 2014 Ghana Demographic and Health Surveys (DHS) which were executed by the Measure DHS Program. The DHS Program conducts these surveys for several low-and middle-income countries.
The DHS generally collates information on child and maternal health, including issues on stunting. Surveys of the DHS Program such as the ones included in this study utilize a twofold sampling procedure. In Ghana, the initial stage constituted the systematic selection of clusters/enumeration areas within rural and urban settings of Ghana. The second stage was characterized by household selection within the enumeration areas that were selected in stage one. Eligible women (permanent residents and those who joined the households the night before the survey) were subsequently interviewed [7]. A total of 10,826 (2,529 in 1998; 2,874 in 2003; 2,529 in 2008; 2,894 in 2014) women were included in this present study.

Dependent variable
Stunting among children below ve years was our dependent variable. The dependent variable, stunting, was measured by the DHS by using the WHO Child Growth Standards [15]. As such, the DHS collected data on each child's height/length, sex, and age to compute the number of standard deviations (i.e. z-score) to determine whether the child's height is above or below the median of the 2006 WHO growth reference population. Stunting, therefore, was de ned as a z-score less than -2 and not stunted if otherwise [15].

Independent variables
A total of four inequality strati ers served as the independent variables for this study. The rst is economic status, which was computed using the Principal Component Analysis (PCA). It was derived by segregating households into ve levels based on ownership of some cardinal assets (e.g. television and bicycle) and dwelling characteristics (e.g. oor and roo ng material). The second is education, measured as no education, primary education, and secondary education or higher. The third is the place of residence (rural or urban) whilst the sex of the child was either male or female. Finally, the region of residence comprised all the then ten administrative regions of Ghana.

Analysis
We analysed the data with the assistance of the 2019 updated version of WHO's HEAT software via the WHO Health Equity Monitor database [16]. Four principal summary measures were employed in our analysis. These four measures are Ratio (R), Difference (D), Population Attributable Fraction (PAF), and Population Attributable Risk (PAR). These four distinct summary measures were employed due to the recommendation by WHO that the usage of different summary measures helps to generate outcomes that are sensitive to policy formulation [17].
In deriving our summary measures, the following procedures were followed. Concerning economic status, D was computed by subtracting stunting prevalence among children of poorest women (quintile 1) from the stunting prevalence among children of richest women (quintile 5). On education, stunting prevalence among the children of women without education was subtracted from the prevalence among children of women who had secondary/higher education. Similarly, prevalence among children of rural residents was subtracted from the prevalence among children of urban residents. The D for the region variable was calculated as the region with the maximum prevalence of stunting minus the region with the minimum prevalence across the respective surveys.
In computing R, it was calculated as the ratio of two different populations, i.e. R=Y high /Y low . In the case of a residence, R denoted a place of residence where Y high stood for urban and Y low stood for the rural population. With education, Y high implied children of women with secondary or higher education where Y low represented children of women with no education. For wealth quintile, Y high was the richest quintile whilst Y low was the poorest quintile. In the same manner, Y high represented males or females, depending on the category with the highest prevalence in a particular survey. The PAR was derived by ascertaining the difference between estimates of the reference sub-populations (known as yref) of the national mean of stunting among children under 5. With this, (μ): PAR = yref-μ, with μ being the national mean of stunting. Likewise, PAF denoted the relative inequality dimension of PAR and it was derived as PAF = (PAR/ μ)*100.

Ethical issues
Data used for this study is a publicly available de-identi ed data. Ethical approval for Ghana DHS was granted by the Ghana Health Service and the Ethical Review Board of the Measure DHS. All participants consented either in writing or verbally before participating in the surveys.

Results
Trends in stunting prevalence in children under age 5, disaggregated across ve inequality dimensions, 1998-2014 Table 1 shows the trends in disaggregated stunting prevalence among children below

Discussion
This study examined the inequalities in stunting prevalence among children under ve years in Ghana between 1998 and 2014. The educational dimension of stunting among children under ve years has shown improvements over the studied period. Maternal educational level emerged as a key variable that contributes to the inequalities in stunting among children under ve years. Our nding that stunting is more common among children of women with no/low educational attainment is in line with previous studies conducted in South Asia [18], some sub-Saharan African countries [19], Nigeria [20], and Sierra Leone [21]. The possible reason for this ndings could be that more educated women are likely to utilize healthcare services which in turn, may affect health-related decisions that improve child nutritional outcomes, such as stunting [22]. This suggests that addressing disparities in stunting among children under ve years in Ghana will need among other things a strong commitment in increasing mothers' education by paying critical attention to the inequalities in educational attainment between socio-economic groups in the country. Also, designing educational interventions to equip mothers with the necessary knowledge of the nutritional needs of their children may help prevent stunting among children of mother with no/low formal education.
Consistent with previous studies conducted in Nepal [23], Nigeria [20], and Sierra Leone [21], our ndings showed that inequalities in childhood stunting were prevalent among children from the poorest wealth categories. The plausible reason could be that people in the poorest wealth quantile may encounter nancial challenges in their attempt to access nutritious foods for their children, and this may increase the likelihood of stunting in their children. The socio-economic status continues to be an important policy lever that policymakers can use to address a wide range of issues.
Place of residence was found to be a signi cant contributor to the inequalities in stunting prevalence among children under ve years in Ghana. Comparable with previous studies in sub-Saharan Africa as a whole [24] and in speci c countries like Nigeria [20] and Sierra-Leone [21], stunting prevalence among children under ve years dominates among rural residents compared to urban residents. The widest variation of stunting occurred between 1998 and 2003, and that could be due to the inequitable distribution of socio-economic conditions in the country [7]. The study highlighted not only the widest variation of stunting in the rural areas but the uctuating rate of stunting prevalence among children under ve years in the country over the studied years. This nding calls for a collective effort by policymakers to focus on closing the urban-rural gap in terms of stunting burden among children under ve years.
The present study revealed disparities in stunting prevalence across the geopolitical regions in Ghana. Data from Ghana DHS show that stunting prevalence among children under ve varies by geographical regions in the country [7], and the Northern region consistently accounted for the greatest proportion of stunting prevalence than any other region in the country. The regional inequality has shown uctuation over the studied time by the different measures of inequality. The regional disparities found in Ghana present an interesting picture that needs further investigation to identify the drivers for this disparity to pave way for the implementation of context-speci c interventions that would help eliminate the sub-national region-related stunting disparity.
Finally, our nding showed sex-related stunting inequality favouring female children. This nding is congruent with previous studies conducted in Nigeria [20], Senegal [25], and Sierra Leone [21] that demonstrated that female children have lower odds of experiencing stunting than their male counterparts. The simple measures indicated a signi cant disparity in stunting at the detriment of male children throughout the period studied. The simple measure of inequality (D) remained unchanged between 1998 and 2003 and declined afterwards.

Strengths And Limitations
The main strength of this study lies in the use of four large nationally representative data with a large sample size, which warrant a high precision of the ndings. Also, Ghana DHS used the standardized tools, which are reliable. Additionally, we investigated the stunting disparity using the HEAT software which allows us to do the inequality analysis with high standard of quality. Despite these strengths, there is a limitation inherent in the study that needs to be acknowledged. We did not explore the root causes of stunting disparity in the country. However, programmes and interventions intended to reduce stunting in Ghana may need information on the root causes of such disparities. This highlights the need for further qualitative studies to explore the reasons for the existence of stunting disparity in the country across different population groups.

Conclusion
We examined inequalities in the determinants of stunting prevalence among children under ve years in Ghana between 1998 and 2014. Inequalities in stunting prevalence in Ghana is to the disadvantage children of poorest wealth quintile, uneducated mothers, male children, rural residents, and those of the Northern region of Ghana. We recommend the introduction and strengthening of equitable interventions focusing on nutrition on sub-populations in the country who suffer from a higher burden of stunting. Abbreviations