1. Introduction
As defined by the WHO, undernutrition has four broad sub-forms: stunting, wasting, underweight, and deficiencies in vitamins and minerals [
1]. However, the phenomenon when these four forms co-occur in a child has not been studied in the literature. Svedberg (2000) came up with the composite indicator of child anthropometric failure (CIAF) to reflect the true burden of undernutrition at the individual level, studying all possible co-occurrences from combinations of stunting, wasting, and underweight [
2]. Such indices help identify communities or areas where many children experience multiple failures and allocate resources to the areas of greatest need [
3]. The seven different categories of CIAF, as explained by Nandy (2005), are A: “no failure”, which means children who do not suffer from any anthropometric failure; B: “wasting only”, which means children with an acceptable weight and height for their age but who have subnormal weight for their height; C: “wasting and underweight”, which means children with above-normal heights but whose weight for their age and weight for their height are too low; D: “wasting, stunting, and underweight”, which means children who suffer from anthropometric failure on all three measures; E: “stunting and underweight”, which means children with a low weight for their age and a low height for their age but who have an acceptable weight for their height; F: “stunting only”, which means children with a low height for age but who have an acceptable weight, both for their age and for their short height; and, lastly, Y: “underweight only”, which means children who are only underweight [
4]. Categories B: “wasting only”, F: “stunting only”, and Y: “underweight only”, are also termed as standalone conditions.
Quoted from a 2019 report by the Government of India,
Figure 1 is a Venn diagram showing the co-existence of multiple forms of undernutrition among under-five children in India using NFHS 2015–2016 data [
5]. Among children aged 0–5 years, 6.5% of children were stunted and wasted, as well as underweight; 18.4% of children were stunted and underweight, and 8.2% of children were wasted and underweight. It revealed that after disaggregating the co-existence of these three conditions, 13.6% of children were only stunted (against a 38.4% overall prevalence of stunting), 2.6% were only underweight (against a 35.7% overall prevalence of underweight), and 6.3% (against a 21% overall prevalence of wasting) were wasted. State-wise analysis showed that Jharkhand (10.9%) led with the highest prevalence of multiple burdens of malnutrition encompassing stunting, wasting, and underweight conditions among under-five children, followed by Madhya Pradesh (8.5%) and Bihar (8.1%).
The fourth sub-form of child undernutrition, involving deficiencies in the intake of essential vitamins and minerals, commonly known as micronutrients, when grouped with stunting, wasting, and underweight, can help understand the real burden of undernutrition. In many cases where diets are poor in micronutrients, multiple micronutrient deficiencies are likely to affect the development of anaemia synergistically [
6]. The WHO defines anaemia in children aged under 5 years as a haemoglobin concentration <110 g/L at sea level and is associated with increased risks for child mortality, negatively impacting the cognitive and physical development of children. If we take anaemia as a proxy for representing a lack of essential vitamins and minerals, there are many instances in the literature that analyse different forms of child undernutrition interacting or co-occurring with one another [
7]. For example, a child cannot be stunted and wasted at the same time without underweight, as it is physically not possible since there is a high effect of underweight on the concurrence of both [
8]. A recent study showed that stunting and wasting are linked and that wasting can increase the risk of subsequent stunting [
9]. Another study tried to assess the role of underweight in predicting the stunting status of the child using CNNS 2016–2018 data and concluded that it could be used as a substitute for surveys that poorly measured length or height data [
10].
Similarly, essential micronutrients play a vital role in fostering physical growth as they help produce various necessary enzymes and hormones that aid in regulating biological processes in our body [
11]. Mohammed (2019) found a high level of CAS (concurrent anaemia and stunting) among infants and young children in Ethiopia that was associated with various dietary and non-dietary factors [
12]. Some studies have also examined the concurrences of anaemia and different growth indicators at the population level. A recently published article analysed clustering in Indian districts of 19 pairs of combinations of dual burdens of different nutritional outcomes and found that several of them had significantly higher prevalence at the state and district levels [
13].
Findings from the 2019 GBD study by the ICMR suggest that the malnutrition targets set by India’s National Nutrition Mission (NNM) are aspirational, and the rate of improvement needed to achieve these targets is much higher than the rate observed presently, which might be challenging to reach in a short period [
14]. Child growth anthropometric failures and anaemia are the most commonly used indicators for assessing the nutritional status of children. Still, their overlapping is rarely studied. A better understanding of clustering between different nutritional outcomes is required, as co-existing forms of malnutrition (CFM) in any form result in a heightened risk of distinct health adversities, diverging from comparable standalone conditions [
15]. Additionally, a shift in how child undernutrition is understood and managed is urgently needed if the World Health Assembly and the UN Sustainable Development Goal targets are to be met.
Similar to the dual or multiple burdens of malnutrition when two or more forms of malnutrition co-occur within individuals, this study tried to identify the single, dual, triple, and quadruple burdens of child undernutrition by studying the co-occurrences of stunting, wasting, underweight, and anaemia among under-five children in India. Spatial analysis of such co-occurrences at the district level can help the government plan interventions as per the intensity of different co-occurrences across geographies. Therefore, this study tried to understand the clustering of child undernutrition outcomes at the individual as well as the population levels.
2. Materials and Methods
2.1. Data Source and Study Population
Data from the National Family Health Survey (NFHS), which is the Indian version of the Demographic Health Survey (DHS), was used in this study. The NFHS is a popularly known household survey in India that collects demographic and health-related information every few years from respondents, including women, men, and children and household members with specialised tools for each of these types of respondents. It also collects blood samples and provides information on biomarkers like height, weight, haemoglobin, etc. Up until now, data from five survey rounds have been collected, and the latest round, NFHS-5 (2019–2021), has collected information from over 636,699 households. The NFHS uses a multistage stratified sampling approach for producing district and state-level estimates, and their detailed sampling strategy can be accessed from their published reports.
For the present study, the Round V 2019–2021 data of NFHS were mainly analysed. Round III 2005–2006 and Round IV 2015–2016 datasets of NFHS were used for comparison purposes to observe trends. Data from the Comprehensive National Nutrition Survey (CNNS) were also used in a few instances, but only for descriptive statistics since the estimates are not representative at the district level. Regarding software, STATA version 15 was used for analysing all the data. Since this study is based on secondary data from various surveys conducted in India, these datasets have been archived in a public repository; therefore, the data are easily accessible, and ethical approval was not needed to conduct this study. Sampling weights were used for all computations and analysis.
The NFHS, through its women’s, biomarker’s, and household’s questionnaires, collects information on multiple domains like birth history, household amenities, source of toilet facilities, type of cooking fuel used in the household, education, etc. Since our outcome variables involved the use of data on height, weight, age, haemoglobin, and WHO-suggested z-scores like height-for-age z-scores (HAZ), weight-for-height z-scores (WHZ), and weight-for-age z-scores (WAZ), the plausible cases which were flagged as “out of the permitted ranges” in the NFHS dataset were dropped. In total, NFHS-5 (2019–2021) collected information from around 198,475 children aged 6–59 months, as accessed from the “kids” file of the NFHS from the publicly available datasets on the website dhsprogram.com on 19 March 2023. After excluding all the children whose information was missing or plausible for the outcome variable, our study performed an analysis on the final sample size of 175,289 children aged 6–59 months. Children aged 0–5 months were not included since information on anaemia was not collected for them.
2.2. Computing the Outcome Variable, Modified CIAF + Anaemia
As described earlier, the traditional CIAF utilises information on the stunting, wasting, and underweight status of each child and categorises children into seven categories in such a way that we get to know who are the children who are free from any form of undernutrition (i.e., none), who are the ones suffering from only one form or standalone forms (that is, only stunting, only wasting, or only underweight), who are the ones suffering from any two of the three forms of undernutrition (e.g., wasting and underweight, stunting and underweight), and who are the ones who are suffering from all three forms of undernutrition (stunting, wasting, and underweight). These co-occurrences are also termed as anthropometric failures (AFs). A modified version of the CIAF was computed in the same way while taking into consideration the status of anaemia as well. The
Table 1 describes the fourteen mutually exclusive categories of our outcome variable, or the four major types of burdens or co-occurrences of child undernutrition in which children under the age of five could be categorised.
2.3. Analysis
As part of the descriptive statistics, the trend of all four undernutrition outcomes, in general, was studied across NFHS survey rounds and the CNNS. The co-occurrences at the individual level were observed, and, as listed in
Table 1, the prevalence of the fourteen manifestations of child undernutrition was computed. Out of the fourteen, the trend of the most prevalent co-occurrences was studied across NFHS survey rounds. Particularly, the pattern of quadruple burden of child undernutrition, that is, when the child is suffering from all four forms of undernutrition, was also studied with respect to state and the child’s age in months using the latest round data of NFHS. District-level prevalence of the same was represented through a spatial map.
With the help of the literature and data available, different explanatory variables were selected, and their distribution was analysed as part of the univariate analysis or sample description using data from NFHS-5 (2019–2021). For the bivariate analysis, all the types of burdens or co-occurrences of child undernutrition were studied across various background characteristics and maternal and child characteristics. For assessing the association between the outcome variable and the covariates, the chi-square test of association was used for testing statistical significance. Ordered logistic regression was run for the outcome variable with 5 categories (no burden, single burden, dual burden, triple burden, and quadruple burden for child undernutrition) to identify determinants of burdens of child undernutrition in India. Further, binary logistic regression was also run to confirm the determinants of some of the most prevalent co-occurrences while coding the co-occurrences into binary format, 1 representing “yes” for the co-occurrence and 0 representing “no” for the remaining children. A variable description for each independent variable considered is given in
Table 2.
For analysing clustering at the population level, spatial analysis across districts was conducted for the data of NFHS Round V 2019–2021 using the GeoDa software v1.18. Shapefiles were accessed from dhsprogram.com, and spatial autocorrelation using univariate local Moran’s I statistic is computed for some of the most prevalent burdens to study how clustered they are at the district level. The Moran’s I statistic lies between the range of −1 and 1 and could be defined as the effect of an attribute of one district on that of its neighbouring districts. It is measured as the slope of the regression run on the spatial lag of the variable with respect to the variable itself, where the spatial lag of a specified variable is computed by taking the weighted average of the variable of the neighbouring districts. Values of Moran’s I greater than 0 suggested clustering of similar values, that is, high values near high values or low values near low values. Values less than 0 indicate spatial dispersion, that is, high values surrounded by low values and vice versa. Values near 0 suggest a random spatial pattern, meaning no significant clustering. A pseudo p-value is computed for testing the significance of each value of Moran’s I statistic using the permutation-based randomisation function of GeoDa. Queen contiguity weights were used, which define the neighbours of a district as all the adjacent districts that share a common edge or common vertex with it.
For comparison between the magnitude of the district-level clustering of the existing indicators of the four forms of child undernutrition outcomes, the co-occurrences from the traditional CIAF and those from the modified CIAF + anaemia version, a univariate local Moran’s I statistic was also computed for them. For example, a comparison in district-level clustering of the nutrition failure or anthropometric failure of “only stunting” or “none” is possible, since both these categories are observed in the traditional CIAF as well as the modified CIAF + anaemia. Spatial autocorrelation was not computed for other categories or co-occurrences as their district-level prevalences were quite low.
Moving forward in the comparison, bivariate Moran’s I is also analysed to study the co-clustering between existing indicators of forms of child undernutrition outcomes, the co-occurrences from the traditional CIAF, and those from the modified CIAF + anaemia. Bivariate Moran’s I statistics show the degree of spatial association between the spatial lag of one variable with respect to another variable. Again, only some of the co-occurrences are studied that were found to be more prevalent. Similar to univariate local Moran’s I, the bivariate local Moran’s I measures whether high (or low) values of one variable in a given location are associated with high (or low) values of another variable in neighbouring locations.
Taking the significant explanatory variables found from the analysis conducted for studying co-occurrences at the individual level, spatial analysis is particularly conducted for identifying the causes behind the clusters of the quadruple burden of child undernutrition. District-level prevalences are computed for the explanatory variables, and the quadruple burden of child undernutrition and univariate and bivariate Moran’s I are computed. Bivariate LISA (local indicator of spatial association) maps are also generated to assess the hotspots of the quadruple burden of child undernutrition alongside the explanatory variables. Hotspots refer to the areas where high/high clustering is observed; cold spots are where low/low clustering is observed, and spatial outliers or poor clustering is observed where high/low and low/high values occur alongside the neighbouring districts.
Taking selected explanatory variables from the findings of bivariate local Moran’s I, spatial regression was conducted to assess the spatial determinants of the quadruple burden of child undernutrition. A spatial lag regression model was run to study how a dependent variable in a district is affected by the independent variable in that district as well as in neighbouring districts. Regression diagnostic parameters like R square and the Akaike information criterion (AIC) were computed for the selection of the spatial lag regression model. R square represents the proportion of variation explained in the outcome variable, and its value lies between zero and one, where values closer to one signify that the model fits the data well. On the other hand, lower values of the AIC signify a better fit of the model.
4. Discussion
The present study began by analysing the prevalence and trends of the four child undernutrition outcomes: stunting, wasting, underweight, and anaemia. The study outlined the rising trends of anaemia, which is currently an alarming public health concern in India [
16]. The study also analysed the age patterns of the four child undernutrition outcomes that portray a pattern similar to what was observed in the CNNS 2016–18 Report [
17].
The study further proceeded to compute the prevalence of the traditional composite index of anthropometric failure as coined by Svedberg and Nandy [
2,
4]. The importance of studying CIAF is immense, as it is seen as a better indicator to assess undernutrition than the existing measures generally used, which are stunting, wasting, and underweight [
18]. The literature highlights that areas with a high prevalence of co-occurrences of stunting, wasting, and underweight carry a higher burden of child mortality in India [
19,
20,
21]. The findings of the present paper were in convergence with similar studies that had computed CIAF using datasets of NFHS-5 and CNNS, which found that around half of the children were free from stunting, wasting, and underweight, and the other half were burdened with one issue or the other [
22,
23,
24].
The present study also tried to modify the CIAF by including anaemia as a substitute for the fourth form of undernutrition, which is micronutrient deficiencies, the first three being stunting, wasting, and underweight. This way, the newly formed index of CIAF + anaemia tried to encapsulate all four major forms of child undernutrition holistically. But this was not the first time one has attempted to modify the CIAF. Given the rising trend of overnutrition, many have tried to add overweight or obese as a component alongside stunting, wasting, and underweight into the CIAF [
25,
26,
27]. Some have tried to modify CIAF by replacing underweight indicator calculated from weight-for-height with that computed from BMI-for-age [
28]. Besides the CIAF, various studies in the literature have determined co-occurrences among different child malnutrition indicators [
29,
30,
31,
32].
The present study identified the dominant role of two child undernutrition indicators; one is stunting, which signifies chronic undernutrition and is well-known for its scarring effect; the other is anaemia, a silent killer of productivity and one’s well-being, which has recently caught everyone’s eyes, given its rising trend. There is a wide literature that analyses the co-occurrence of especially stunting and anaemia, as it is bound to have stark consequences for one’s health [
12,
33,
34,
35,
36]. Analysing the co-occurrence of stunting and wasting is another popular phenomenon [
37,
38,
39,
40].
There is a dearth of research in India that studies the co-occurrence of all four outcomes as studied in this paper, but a study conducted in Ethiopia has performed a similar exercise and found that two-thirds of the children had at least one or the other issue out of the four undernutrition conditions, namely, stunting, wasting, underweight, and anaemia, and called this index the multiple nutrition deficits index [
41]. Similar to what was observed in our study, it studied the association of multiple nutrition deficits and discovered that male children, those older, from poorer households, and with mothers belonging to the illiterate category were more likely to have multiple nutrition deficits.
Varghese (2019) analysed the mean prevalences of the dual burden of stunting, anaemia, and overweight among children at the individual and population levels with respect to states and districts, and, similar to our study, a strong presence of stunting and anaemia was also found at the district level [
13]. As our research identified the worst-performing districts in terms of the quadruple burden of child undernutrition, similarly, another study using NFHS-4 data identified hotspots of higher prevalences of co-occurrences of stunting, wasting, and anaemia [
42].
The country nutrition profiles maintained by the global nutrition report assessed that India is “on course” to achieve three of its global nutrition targets in 2025, “off course” for achieving targets on seven indicators, and “a worsening trend” for two indicators, which include wasting and anaemia [
43]. The current scenario of child undernutrition in India calls for urgent actions to plan the effective use of nutrition-generated data for effective pathways for our country to meet its SDG 2030 targets [
44].
The Indian government’s oldest flagship program to prevent undernutrition had been ICDS, launched in 1975, followed by mid-day meal in 1995. Since then, the government has brought several other schemes and programs like RBSK under NHM, the National Food Security Act, and the Swachh Bharat mission that help in fighting undernutrition challenges in India. The most recent initiatives include POSHAN Abhiyaan, Anaemia Mukt Bharat, and PMMVY. Despite the government’s efforts, there is a requirement for supportive supervision in each of these programs to ensure their effectiveness on the ground and develop a multidimensional approach to address the burden of malnutrition in India. There is a need for effective convergence strategies among different ministries to come together for a joint mission of a “suposhit Bharat” [
45].
This study identifies mechanisms to identify nutritionally at-risk children and recommends catering to the needs of such children, prioritising those who are burdened with more than one form of undernutrition and those belonging to a nutritionally at-risk district. A system that tracks such families and highlights a scoring system based on these parameters can help identify who needs the most support. In conclusion, analysing such burdens with the help of smart data use can help to reduce the burden of undernutrition in our country and can be a supportive step for our government, as it has the potential for substantial programmatic implications [
46]. There is a need to understand the co-morbidities of nutritional outcomes and gain more insights on multifactorial approaches for enhancing public health nutrition interventions accordingly [
47]. Action can be directed towards investing in children with multiple nutritional deficits with enhanced tracking, screening, and service delivery across public health platforms.
This study tried to make a unique contribution to identifying the burdens of child undernutrition at individual and population levels, but it also carries some limitations. Firstly, there exists scope for improvement in the data quality of different nutrition indicators [
48]. The data of any large-scale survey carry missing values, which do have a scope of imputation to strengthen the completeness of data, which has not been attempted in this study. The fact that NFHS-5 (2019–2021) was collected in two phases, as per the nation’s COVID restrictions, is bound to impact the quality of its data, as it also elongated the survey schedule. Secondly, there is an argument regarding the suitability of one-size-fits-all WHO standards of growth and other nutrition indicators in the Indian context, as misclassification of a child can also add to the inflation of child undernutrition outcomes [
49]. Additionally, this study uses anaemia as a proxy for the fourth form of undernutrition, which is micronutrient deficiencies. But it is only 70% of the time when anaemia is caused due to nutritional deficiencies (iron-deficiency anaemia, folate- or B12-deficiency anaemia, or dimorphic anaemia), and the remaining 30% of the time, it could be due to anaemia of inflammation or anaemia of other causes [
50]. Besides, in NFHS-5, anaemia was measured using capillary blood samples, which are more convenient for field surveys, though venous samples are generally more accurate. Thirdly, the study used data that were collected using a cross-sectional design, which makes it unfit for establishing causality and requires further in-depth research. Because this study is based on secondary data sources, it is bound to miss capturing the variation caused by indicators whose data were not collected in the survey. To cover information on such chance causes, this study involved statistical calculations, whose findings are subject to the fulfilment of typical assumptions that may be violated in specific scenarios.
The study also offers a further scope of research in addressing child undernutrition in India. There is scope for state-specific scrutiny to dig deeper and analyse the factors playing a role in state-specific contexts. There is scope for future research for getting more robust scientific evidence to confirm whether the co-occurrences like “SUA”, “SA”, and “only anaemia” play a distinct role from the previously used indicators of stunting, wasting, underweight, and anaemia, requiring specialised treatments. As all four forms of undernutrition co-occur and often have the same population risk factors, there is a chance of a bi-directional or multi-directional time-dependent relationship among the four forms of child undernutrition. There is a need for evidence and inference to understand how these four forms of undernutrition co-occur dynamically, what changes they cause biologically, and how they cause or interact with one another.