Severe Childhood Malnutrition Research Articles

The Growing IDPs in the Country and Impact on Childhood Malnutrition: Averting a Future Generation with Stunted Growth and Knowledge

Al least 80,000 people are forcefully displaced from their homes every 24 hour across the globe while in Nigeria the total number of IDPs in 2018 stands at 2.1 million. Among the major challenges facing the IDPs in camps scattered across the country is severe childhood malnutrition. This could lead to poor physical, mental and psychological development of children leading to the breeding of a large segment of children with stunted growth and associated compromised number recall, conceptual thinking, general cognition, and attention deficit which could manifest prominently in adult life. All efforts should therefore be intensified to meet adequate nutritional needs of all children in IDPs camps to ensure a healthy physical and mental future generation.

Women's asset ownership and children's nutritional status: Evidence from Papua New Guinea

This study examines how women's asset ownership is associated with children's nutritional status in Papua New Guinea, a country with some of the most severe child malnutrition in the world. The 2009–2010 Household Income and Expenditure Survey is employed, but restricted to children under the age of 72 months living with married mothers, leaving a final analytic sample of 1651. Asset ownership is expected to strengthen mothers' income-generating capacity and their bargaining power within the home, which increases investments in children's health. Women's ownership of fishing and agricultural equipment (important for meeting subsistence needs and for generating cash earnings) appears to be driving most of the results. OLS regression results point to beneficial effects of maternal asset ownership for children's height-for-age, weight-for-height, and weight-for-age Z-scores, and results from detailed quantile regressions indicate that these effects occur at various parts of the distribution, especially for children's WAZ scores.

Early Childhood Dental Caries, Mouth Pain, and Malnutrition in the Ecuadorian Amazon Region.

Malnutrition and dental caries in early childhood remain persistent and intertwined global health challenges, particularly for indigenous and geographically-remote populations. To examine the prevalence and associations between early childhood dental caries, parent-reported mouth pain and malnutrition in the Amazonian region of Ecuador, we conducted a cross-sectional study of the oral health and nutrition status of 1407 children from birth through age 6 in the “Alli Kiru” program (2011–2013). We used multivariate regression analysis to examine relationships between severe caries, parent-reported mouth pain measures, and nutritional status. The prevalence of dental caries was 65.4%, with 44.7% of children having deep or severe caries, and 33.8% reporting mouth pain. The number of decayed, missing and filled teeth (dmft) increased dramatically with age. Malnutrition was prevalent, with 35.9% of children stunted, 1.1% wasted, 7.4% underweight, and 6.8% overweight. As mouth pain increased in frequency, odds for severe caries increased. For each unit increase in mouth pain frequency interfering with sleeping, children had increased odds for being underweight (Adjusted Odds Ratio (AOR): 1.27; 95% CI: 1.02–1.54) and decreased odds for being overweight (AOR: 0.76; 95% CI: 0.58–0.97). This relationship was most pronounced among 3–6 year-olds. Early childhood caries, mouth pain and malnutrition were prevalent in this sample of young children. Parent-reported mouth pain was associated with severe caries, and mouth pain interfering with sleeping was predictive of poor nutritional status. We demonstrate the utility of a parsimonious parent-reported measure of mouth pain to predict young children’s risk for severe early childhood caries and malnutrition, which has implications for community health interventions.

Beberapa Faktor Risiko Gizi Kurang dan Gizi Buruk pada Balita 12-59 Bulan (Studi Kasus di Kota Pontianak)

Background: Moderate and severe malnutrition cases in Pontianak City increases each year although a nutritional improvement program has been held by the Health Department of Pontianak City.Method: The type of research was observational using the quantitative study design of case control study and the qualitative study through in-depth interview (mixed method). The number of samples was 80 people consisting of 40 people from case and 40 people from control. Assessment of nutritional using anthropometry measurement based on weight for height. Height measurement using microtoise and measure weighting scale.Results: The multivariate analysis found 2 variables significantly associated with the prevalence of moderate and severe malnutrition in children under five years old aged 12-59 months, i.e.: poor of attitude toward food (OR = 6.980) and poor environmental health (OR =5.033). There were 9 variables which were not associated with nutritional status, not given exclusive breastfeeding, energy intake is less, protein intake is less, frequency of Severe Acute Respiratory Infection equal to over three times in the last two months, frequency of diarrhea equal to over three times in the last two months, low monthly family income, number of children more than two, low mother's education, and frequency of watching TV more than two hours a day.Conclusion: Based on the results above, it can be concluded that the risk factors associated with the prevalence of moderate and severe malnutrition are poor of mother's attitude toward food is poor health and poor environmental.

Beberapa Faktor Risiko Gizi Kurang dan Gizi Buruk pada Balita 12-59 Bulan (Studi Kasus di Kota Pontianak)

Background: Moderate and severe malnutrition cases in Pontianak City increases each year although a nutritional improvement program has been held by the Health Department of Pontianak City.Method: The type of research was observational using the quantitative study design of case control study and the qualitative study through in-depth interview (mixed method). The number of samples was 80 people consisting of 40 people from case and 40 people from control. Assessment of nutritional using anthropometry measurement based on weight for height. Height measurement using microtoise and measure weighting scale.Results: The multivariate analysis found 2 variables significantly associated with the prevalence of moderate and severe malnutrition in children under five years old aged 12-59 months, i.e.: poor of attitude toward food (OR = 6.980) and poor environmental health (OR =5.033). There were 9 variables which were not associated with nutritional status, not given exclusive breastfeeding, energy intake is less, protein intake is less, frequency of Severe Acute Respiratory Infection equal to over three times in the last two months, frequency of diarrhea equal to over three times in the last two months, low monthly family income, number of children more than two, low mother's education, and frequency of watching TV more than two hours a day.Conclusion: Based on the results above, it can be concluded that the risk factors associated with the prevalence of moderate and severe malnutrition are poor of mother's attitude toward food is poor health and poor environmental.

The association between nutritional status and motor development in children under five years old

Background Severe malnutrition in children is closely related todelayed physical growth and mental development. Very few re-ports mention the effects of mild to moderate malnutrition on mo-tor development.Objective The objective of this study was to determine the rela-tionship between nutritional status and motor development in earlychildhood.Methods In this cross-sectional study, we examined body weightof children under 5 years of age, the ability to sit or walk withoutsupport, and parachute sign in those under 2 years of age whocame to community child health surveillance posts in TumintingSubdistrict, Manado, Indonesia.Results Among 359 under-five children, 296 were well-nourishedand 63 had mild to moderate malnutrition. The ability to sit withoutsupport in malnourished children was significantly delayed com-pared to that in well-nourished ones (P=0.03). The ability to walkwithout support and parachute sign were not significantly differentbetween the two groups.Conclusion The ability to sit without support in children with mildto moderate malnutrition is delayed compared to that in well-nour-ished ones

Malnutrition-associated liver steatosis and ATP depletion is caused by peroxisomal and mitochondrial dysfunction

Severe malnutrition in young children is associated with signs of hepatic dysfunction such as steatosis and hypoalbuminemia, but its etiology is unknown. Peroxisomes and mitochondria play key roles in various hepatic metabolic functions including lipid metabolism and energy production. To investigate the involvement of these organelles in the mechanisms underlying malnutrition-induced hepatic dysfunction we developed a rat model of malnutrition. Weanling rats were placed on a low protein or control diet (5% or 20% of calories from protein, respectively) for four weeks. Peroxisomal and mitochondrial structural features were characterized using immunofluorescence and electron microscopy. Mitochondrial function was assessed using high-resolution respirometry. A novel targeted quantitative proteomics method was applied to analyze 47 mitochondrial proteins involved in oxidative phosphorylation, tricarboxylic acid cycle and fatty acid β-oxidation pathways. Low protein diet-fed rats developed hypoalbuminemia and hepatic steatosis, consistent with the human phenotype. Hepatic peroxisome content was decreased and metabolomic analysis indicated peroxisomal dysfunction. This was followed by changes in mitochondrial ultrastructure and increased mitochondrial content. Mitochondrial function was impaired due to multiple defects affecting respiratory chain complex I and IV, pyruvate uptake and several β-oxidation enzymes, leading to strongly reduced hepatic ATP levels. Fenofibrate supplementation restored hepatic peroxisome abundance and increased mitochondrial β-oxidation capacity, resulting in reduced steatosis and normalization of ATP and plasma albumin levels. Malnutrition leads to severe impairments in hepatic peroxisomal and mitochondrial function, and hepatic metabolic dysfunction. We discuss the potential future implications of our findings for the clinical management of malnourished children. Severe malnutrition in children is associated with metabolic disturbances that are poorly understood. In order to study this further, we developed a malnutrition animal model and found that severe malnutrition leads to an impaired function of liver mitochondria which are essential for energy production and a loss of peroxisomes, which are important for normal liver metabolic function.

Pemantauan Penanganan Kasus Balita Gizi Buruk dengan Menggunakan Sistem Informasi Spasial di Kota Banda Aceh

ABSTRACTNutrition problem contributes to the death rate of toddler. In Aceh Province during 2013, there are 855 toddlers suffering malnutrition and only 14,04% of them recovered, 2,46% died and there are still 714 more toddlers under treatment.Qualitative descriptive research with observational design through action research approach using Geographical Information System (GIS) are carried out in the city of Banda Aceh where the sample of children with malnutrition are obtained from the result of nutrient status monitoring, weighing routine data in posyandu, investigation of the health facilities and the report from society. The collected dependent data variables are children with severe malnutrition and malnourished children, the residence location of the research subjects, the work place of the nutrient management employee, the community health center (puskesmas) and serving fasilities of children with severe malnutrition by Global Positioning System (GPS).The distribution pattern and regions prone to children with malnutrition are concentrated in Kecamatan Kuta Raja, Kecamatan Meuraxa and Kecamatan Ule Kareng. In those districts, the number of children with severe malnutrition is above 0,6% and the number of malnourished children is also above 1,5% of the minimum tolerance number of children set by the City Health Department of Banda Aceh. The percentage of the weighed children to the number of target (D/S) for those districts is in between 53,7% to 69,5%. The number of recovered children after being treated is 7,2%, while 0,9% are died and 9,9% of the children with severe malnutrition are dropped out. The number and the distribution of nutrient management employee are not sufficient and they are not well trained with 21,2% of the posyandu are active. In the other hand, the number and the distribution of puskesmas and hospital are fairly equally distributed throughout Banda Aceh. The development of severe malnutrition children monitoring management information system creates the information of improvement of children with severe malnutrition, distribution map of nutritional cases, the distribution of human resources and the health facilities, and produces a report of success coverage of nutritional program indicator.The distribution pattern and regions prone to malnutrition are distributed in the coastal area and in the city border which are slum and poor region. The regions also suffer low quantity and quality of nutrient officer, limited operational infrastructure, and only few posyandu are active . The severe malnutrition children monitoring management information system can help through evaluating the improvement of the children’s recovery and it can also produce various information needed. Keywords: Spatial information system, improvement monitoring, toddler, severe malnutrition

Severe malnutrition in children in Papua New Guinea: effect of a multi-faceted intervention to improve quality of care and nutritional outcomes

Background and aims: Severe malnutrition remains a major problem in Papua New Guinea; it is associated with 11% of paediatric hospital admissions and 33% of all child deaths, with a case fatality rate around 20%. This article aims to evaluate the effectiveness of a multi-faceted intervention for improving care for children with severe malnutrition.Methods: Severe malnutrition was defined as weight-for-age (WFA) <-3 Z-scores with severe wasting or mid upper arm circumference <115 mm or generalised oedema owing to malnutrition. The intervention included training for health-care workers on WHO guidelines for severe malnutrition, ward-round checklists, posters and support for nurses to provide better patient nutrition. Three point prevalence surveys were conducted; one before the intervention and two afterwards at 3-month intervals. The main outcomes were weight change since admission, energy intake and the proportion of the calculated required energy intake in the previous 24 hours. Each stage of the WHO guidelines for severe malnutrition management was assessed for adherence.Results: There were significant improvements in the WHO steps for the management of severe malnutrition. At pre-intervention baseline, children received a median of 356 ml/day (IQR 178–450): 31% (95% CI 21–48) of their estimated daily energy requirements for weight. In the first follow-up survey, children received a median of 820 (IQR 600–1110) ml/day: 98% (95% CI 67–100) of daily energy requirements; and in the second follow-up survey they received 780 (IQR 480–900) ml/day: 86% (95% CI 46–100%) of daily requirement (P<0.001 both for volume received and percentage of energy requirements). Median weight gain prior to the intervention was 1.55 g/kg/day (IQR -4.3–6.0) which increased to 5.56 g/kg/day (IQR -3.7–12.0) and 10.19 g/kg/day (IQR 0–16.0) in the first and second follow-up surveys, respectively (P=0.013).Conclusion: Implementation of a multi-faceted intervention to improve the management of children with severe malnutrition was associated with improved quality of care and improved weight gain.

The social context of severe child malnutrition: a qualitative household case study from a rural area of the Democratic Republic of Congo.

IntroductionThe magnitude of child malnutrition including severe child malnutrition is especially high in the rural areas of the Democratic Republic of Congo (the DRC). The aim of this qualitative study is to describe the social context of malnutrition in a rural part of the DRC and explore how some households succeed in ensuring that their children are well-nourished while others do not.MethodologyThis study is based on participant observation, key informant interviews, group discussions and in-depth interviews with four households with malnourished children and four with well-nourished children. We apply social field theory to link individual child nutritional outcomes to processes at local level and to the wider socio-economic environment.FindingsWe identified four social fields that have implications for food security and child nutritional outcomes: 1) household size and composition which determined vulnerability to child malnutrition, 2) inter-household cooperation in the form of ‘gbisa work party’ which buffered scarcity of labour in peak seasons and facilitated capital accumulation, 3) the village associated with usufruct rights to land, and 4) the local NGO providing access to agricultural support, clean drinking water and health care.ConclusionsHouseholds that participated in inter-household cooperation were able to improve food and nutrition security. Children living in households with high pressure on productive members were at danger of food insecurity and malnutrition. Nutrition interventions need to involve local institutions for inter-household cooperation and address the problem of social inequalities in service provision. They should have special focus on households with few resources in the form of land, labour and capital.

Assessing the quality of HIV Counselling, Testing and STI Consultation services for vulnerable populations in Nigeria

supports other findings in which decreased educational years (p1⁄40.019, Fisher’s Exact test) and decreased BMI of the mother (p1⁄4 0.009, Fisher’s Exact test) relates to more severe childhood malnutrition. Interpretation: Due to small sample size, low power of the analysis, and other limitations, we cannot draw conclusions on the relationship between maternal age at marriage and childhood malnutrition, but we do see that, even with this underestimated number, 62.96% of the mothers married under the age of 18 (the legal marrying age for Bangladeshi females). The child, mother, and household characteristics we studied allow us to have a holistic perspective on the social situations of hospitalized children at icddr,b. Future study with large sample and adequate power may help in further understanding the health of the mother in obtaining gravidity and parity and the child through collecting health outcomes of the hospitalized children. Funding: Provided by the Stanford Medical Scholars Fellowship Program. Core Donors of icddr,b financially support the hospital and patient care and include: Australian Agency for International Development (AusAID), Government of the People’s Republic of Bangladesh (GoB), Canadian International Development Agency (CIDA), TheDepartment for International Development, UK (DFID), and Swedish International Development Cooperation Agency (Sida). Abstract #: 02SEDH016

Severe Acute Malnutrition in Childhood: Hormonal and Metabolic Status at Presentation, Response to Treatment, and Predictors of Mortality

Malnutrition is a major cause of childhood morbidity and mortality. To identify and target those at highest risk, there is a critical need to characterize biomarkers that predict complications prior to and during treatment. We used targeted and nontargeted metabolomic analysis to characterize changes in a broad array of hormones, cytokines, growth factors, and metabolites during treatment of severe childhood malnutrition. Children aged 6 months to 5 years were studied at presentation to Mulago Hospital and during inpatient therapy with milk-based formulas and outpatient supplementation with ready-to-use food. We assessed the relationship between baseline hormone and metabolite levels and subsequent mortality. Seventy-seven patients were enrolled in the study; a subset was followed up from inpatient treatment to the outpatient clinic. Inpatient and outpatient therapies increased weight/height z scores and induced striking changes in the levels of fatty acids, amino acids, acylcarnitines, inflammatory cytokines, and various hormones including leptin, insulin, GH, ghrelin, cortisol, IGF-I, glucagon-like peptide-1, and peptide YY. A total of 12.2% of the patients died during hospitalization; the major biochemical factor predicting mortality was a low level of leptin (P = .0002), a marker of adipose tissue reserve and a critical modulator of immune function. We have used metabolomic analysis to provide a comprehensive hormonal and metabolic profile of severely malnourished children at presentation and during nutritional rehabilitation. Our findings suggest that fatty acid metabolism plays a central role in the adaptation to acute malnutrition and that low levels of the adipose tissue hormone leptin associate with, and may predict, mortality prior to and during treatment.

Severe malnutrition among children under the age of 5 years admitted to a rural district hospital in southern Mozambique.

To describe the burden, clinical characteristics and prognostic factors of severe malnutrition in children under the age of 5 years. Retrospective study of hospital-based data systematically collected from January 2001 to December 2010. Rural Mozambican district hospital. All children aged <5 years admitted with severe malnutrition. During the 10-year long study surveillance, 274 813 children belonging to Manhiça’s Demographic Surveillance System were seen at out-patient clinics, almost half of whom (47 %) presented with some indication of malnutrition and 6% (17 188/274 813) with severe malnutrition. Of these, only 15% (2522/17 188) were eventually admitted. Case fatality rate of severe malnutrition was 7% (162/2274). Bacteraemia, hypoglycaemia, oral candidiasis, prostration, oedema, pallor and acute diarrhoea were independently associated with an increased risk of in-hospital mortality, while malaria parasitaemia and breast-feeding were independently associated with a lower risk of a poor outcome. Overall minimum communitybased incidence rate was 15 cases per 1000 child-years at risk and children aged 12–23 months had the highest incidence. Severe malnutrition among admitted children in this Mozambican setting was common but frequently went undetected, despite being associated with a high risk of death. Measures to improve its recognition by clinicians responsible for the first evaluation of patients at the out-patient level are urgently needed so as to improve their likelihood of survival. Together with this, the rapid management of complications such as hypoglycaemia and concomitant co-infections such as bacteraemia, acute diarrhoea, oral candidiasis and HIV/AIDS may contribute to reverse the intolerable toll that malnutrition poses in the health of children in rural African settings.

Microbes and the Malnourished Child

New research implicates a dysfunctional gut microbiome in the etiology of severe childhood malnutrition and confirms a role for antibiotics in its treatment.

Severe malnutrition in children presenting to health facilities in an urban slum in Bangladesh.

An urban slum in Kamrangirchar, Bangladesh. Among children aged 6-59 months seeking medical care from the two Médecins Sans Frontières-supported primary health centres, to determine 1) the prevalence of severe acute malnutrition (SAM) and severe chronic malnutrition (SCM), and 2) the extent of overlap between SAM and SCM. In a retrospective record review, data were analysed from out-patient registers on age, sex, height, weight and mid-upper arm circumference (MUAC) of children attending for medical care from April to September 2011. SAM was defined as weight for height < -3 Z scores of the median and/or MUAC <115 mm. SCM was defined as height for age < -3 Z scores of the median. World Health Organization growth standards were used as reference. Data were complete in the records of 7318 (98%) children, of whom 322 (4%) had SAM and 1698 (23%) had SCM. Among the 322 children with SAM, 162 (50%) also had SCM. In an urban Bangladesh slum, SAM and SCM co-exist, with a predominance of SCM. The current national guidelines for severe malnutrition, which focus on identification and management only for SAM, urgently need to be expanded to include SCM if substantial childhood morbidity and mortality are to be reduced.

Global Efforts to Address Severe Acute Malnutrition

476 5. C hildhood malnutrition encompasses a plethora of nutritional disorders that include stunting, underweight, wasting, severe acute malnutrition (SAM), and micronutrient deficiency disorders. Overweight and obesity, at the other end of the nutritional spectrum, are also manifestations of childhood malnutrition. Nearly 24 million children (younger than 5 years) worldwide experience SAM. The vast majority is located in Africa and Asia (8 million are in India alone). A child with SAM is 10 times more likely to die than a wellnourished child. SAM is one of the top 3 nutrition-related causes of death in children younger than 5 years. Estimates of deaths directly attributable to SAM varied from 0.5 to 2 million annually. Moderate and severe child malnutrition account for 40% to 50% of all deaths in children younger than 5 years. If the United Nations Millennium Development Goals (http://www.un.org/millennium goals) of reducing children malnutrition and mortality by 50% by 2015 are to be met, SAM needs to be prevented and controlled effectively.

HUBUNGAN ANTARA ASUPAN PROTEIN, BESI, DAN SENG DENGAN STATUS GIZI PADA ANAK BALITA GIZI BURUK DI WILAYAH KERJA DINAS KESEHATAN KOTA SEMARANG

Background : Severe malnutrition was threatening children under five years growth. Protein deficiency in long time caused severe malnutrition. Children with severe malnutrition had micronutrients deficiency, like iron and zinc. Iron and zinc deficiency caused nutritional status decreasing. Objective : This research conduct to analyze the association dietary protein, iron, and zinc intake with nutritional status in severe malnutrition children under five years of age. Method : Study cross sectional in 21 severe malnutrition children under five years of age at work region Semarang City Health Department.The data nutritional status were searched using indicator of weight by height (W/H). The data dietary protein, iron, zinc, and fiber intake were searched by semi quantitative food frequency questionnaire (SQFFQ). The data analyzed by SPSS 12.0 for windows. Bivariate analysis used pearson product moment and multivariate analysis used multiple regression linier. Result : Nutritional status subjects which using W/H indicator were -5.72 until -3.02. At 13 until 36 month of age, subjects had 6.8 gr/d until 31.5 gr/d dietary protein intake, 1.3 mg/d until 6 mg/d dietary iron intake, and 1 mg/d until 3.3 mg/d dietary zinc intake. At 37 until 59 month of age, subjects had 11.3 gr/d until 48.5 gr/d dietary protein intake, 2.6 mg/d until 10.2 mg/d dietary iron intake, and 1.5 mg/d until 5.6 mg/d dietary zinc intake. Most of dietary protein (61.9%), iron (90.5%), and zinc (100%) intake were deficit category according to Recommended Dietary Allowances. But, most of dietary protein (61.9%) and zinc (57.1%) were good category, and all of dietary iron was deficit category according to each dietary requirements. There were no association between dietary protein (r=0.143;p=0.27), iron (r=0.089;p=0.35), and zinc intake (r=0.122;p=0.3) with nutritional status in severe malnutrition children under five years of age. Conclusion : There were not evidenced of association between dietary protein, iron, and zinc intake with nutritional status in severe malnutrition children under five years of age. Keywords : Nutritional status, severe malnutrition children under five years of age, protein intake, iron intake, and zinc intake

Community Management of Acute Malnutrition in the Developing World

Globally, acute malnutrition triggers more than 50% of childhood mortality in children under 5 years old, which implies that about 3.5 million children die of malnutrition each year. Prior to the advent of ready-to-use therapeutic food (RUTF), the management of acute malnutrition was limited to hospitals, resulting in low coverage rates with high mortality, as malnourished cases were indentified at later stages often plagued with complications. However, current availability of RUTF has enabled malnourished children to be treated at communities. Further, because RUTF is dehydrated and sealed, it has the added advantage of a lower risk of bacterial contamination, thereby prolonging its storage life at room temperature. Recent data indicate that Community Management of Acute Malnutrition (CMAM) is as cost effective as other high-impact public health measures such as oral rehydration therapy for acute diarrheal diseases, vitamin A supplementation, and antibiotic treatment for acute respiratory infections. Despite the high efficacy of CMAM programs, CMAM still draws insufficient attention for global implementation, suggesting that CMAM programs should be integrated into local or regional routine health systems. Knowledge gaps requiring further research include: the definition of practical screening criteria for malnourished children at communities, the need for systematic antibiotic therapy during malnutrition treatment, and the dietary management of severe malnutrition in children below 6 months of age.

Assessment and Management of Severe Malnutrition in Children

Severe malnutrition is a common cause of morbidity and mortality among children less than five years of age. The World Health Organisation (WHO) has developed two manuals for the in-patient treatment of severe malnutrition. However, these manuals are not widely distributed with the result that most health practitioners caring for severely malnourished children unknowingly use practices that, though may be suitable for sick well nourished children, may be highly dangerous for the severely malnourished child. This review article, based on the two WHO manuals for in-patient treatment of severe malnutrition and other relevant literature, seeks to offer the medical fraternity the opportunity to abreast themselves with the assessment and case management of children with severe malnutrition. Health practitioners caring for children with severe malnutrition should abreast themselves with the recommended guidelines for assessment and management of this common disorder.

Identifying Risk Factors for Severe Childhood Malnutrition by Boosting Additive Quantile Regression

We investigated the risk factors for childhood malnutrition in India based on the 2005/2006 Demographic and Health Survey by applying a novel estimation technique for additive quantile regression. Ordinary linear and generalized linear regression models relate the mean of a response variable to a linear combination of covariate effects, and, as a consequence, focus on average properties of the response. The use of such a regression model for analyzing childhood malnutrition in developing or transition countries implies that the estimated effects describe the average nutritional status. However, it is of even greater interest to analyze quantiles of the response distribution, such as the 5% or 10% quantile, which relate to the risk of extreme malnutrition. Our investigation is based on a semiparametric extension of quantile regression models where different types of nonlinear effects are included in the model equation, leading to additive quantile regression. We addressed the variable selection and model choice problems associated with estimating such an additive quantile regression model using a novel boosting approach. Our proposal allows for data-driven determination of the amount of smoothness required for the nonlinear effects and combines model choice with an automatic variable selection property. In an empirical evaluation, we compared our boosting approach with state-of-the-art methods for additive quantile regression. The results suggest that boosting is an appropriate tool for estimation and variable selection in additive quantile regression models and helps to identify yet unknown risk factors for childhood malnutrition. This article has supplementary material online.