Cesar G. Victora

Maternal and child undernutrition and overweight in low-income and middle-income countries

Maternal and child malnutrition in low-income and middle-income countries encompasses both undernutrition and a growing problem with overweight and obesity. Low body-mass index, indicative of maternal undernutrition, has declined somewhat in the past two decades but continues to be prevalent in Asia and Africa. Prevalence of maternal overweight has had a steady increase since 1980 and exceeds that of underweight in all regions. Prevalence of stunting of linear growth of children younger than 5 years has decreased during the past two decades, but is higher in south Asia and sub-Saharan Africa than elsewhere and globally affected at least 165 million children in 2011; wasting affected at least 52 million children. Deficiencies of vitamin A and zinc result in deaths; deficiencies of iodine and iron, together with stunting, can contribute to children not reaching their developmental potential. Maternal undernutrition contributes to fetal growth restriction, which increases the risk of neonatal deaths and, for survivors, of stunting by 2 years of age. Suboptimum breastfeeding results in an increased risk for mortality in the first 2 years of life. We estimate that undernutrition in the aggregate--including fetal growth restriction, stunting, wasting, and deficiencies of vitamin A and zinc along with suboptimum breastfeeding--is a cause of 3·1 million child deaths annually or 45% of all child deaths in 2011. Maternal overweight and obesity result in increased maternal morbidity and infant mortality. Childhood overweight is becoming an increasingly important contributor to adult obesity, diabetes, and non-communicable diseases. The high present and future disease burden caused by malnutrition in women of reproductive age, pregnancy, and children in the first 2 years of life should lead to interventions focused on these groups.

Maternal and child undernutrition: consequences for adult health and human capital.

Summary In this paper we review the associations between maternal and child undernutrition with human capital and risk of adult diseases in low-income and middle-income countries. We analysed data from five long-standing prospective cohort studies from Brazil, Guatemala, India, the Philippines, and South Africa and noted that indices of maternal and child undernutrition (maternal height, birthweight, intrauterine growth restriction, and weight, height, and body-mass index at 2 years according to the new WHO growth standards) were related to adult outcomes (height, schooling, income or assets, offspring birthweight, body-mass index, glucose concentrations, blood pressure). We undertook systematic reviews of studies from low-income and middle-income countries for these outcomes and for indicators related to blood lipids, cardiovascular disease, lung and immune function, cancers, osteoporosis, and mental illness. Undernutrition was strongly associated, both in the review of published work and in new analyses, with shorter adult height, less schooling, reduced economic productivity, and—for women—lower offspring birthweight. Associations with adult disease indicators were not so clear-cut. Increased size at birth and in childhood were positively associated with adult body-mass index and to a lesser extent with blood pressure values, but not with blood glucose concentrations. In our new analyses and in published work, lower birthweight and undernutrition in childhood were risk factors for high glucose concentrations, blood pressure, and harmful lipid profiles once adult body-mass index and height were adjusted for, suggesting that rapid postnatal weight gain—especially after infancy—is linked to these conditions. The review of published works indicates that there is insufficient information about long-term changes in immune function, blood lipids, or osteoporosis indicators. Birthweight is positively associated with lung function and with the incidence of some cancers, and undernutrition could be associated with mental illness. We noted that height-for-age at 2 years was the best predictor of human capital and that undernutrition is associated with lower human capital. We conclude that damage suffered in early life leads to permanent impairment, and might also affect future generations. Its prevention will probably bring about important health, educational, and economic benefits. Chronic diseases are especially common in undernourished children who experience rapid weight gain after infancy.

Breastfeeding in the 21st century: epidemiology, mechanisms, and lifelong effect

The importance of breastfeeding in low-income and middle-income countries is well recognised, but less consensus exists about its importance in high-income countries. In low-income and middle-income countries, only 37% of children younger than 6 months of age are exclusively breastfed. With few exceptions, breastfeeding duration is shorter in high-income countries than in those that are resource-poor. Our meta-analyses indicate protection against child infections and malocclusion, increases in intelligence, and probable reductions in overweight and diabetes. We did not find associations with allergic disorders such as asthma or with blood pressure or cholesterol, and we noted an increase in tooth decay with longer periods of breastfeeding. For nursing women, breastfeeding gave protection against breast cancer and it improved birth spacing, and it might also protect against ovarian cancer and type 2 diabetes. The scaling up of breastfeeding to a near universal level could prevent 823,000 annual deaths in children younger than 5 years and 20,000 annual deaths from breast cancer. Recent epidemiological and biological findings from during the past decade expand on the known benefits of breastfeeding for women and children, whether they are rich or poor.

Evidence-Based Public Health: Moving Beyond Randomized Trials

Randomized controlled trials (RCTs) are essential for evaluating the efficacy of clinical interventions, where the causal chain between the agent and the outcome is relatively short and simple and where results may be safely extrapolated to other settings. However, causal chains in public health interventions are complex, making RCT results subject to effect modification in different populations. Both the internal and external validity of RCT findings can be greatly enhanced by observational studies using adequacy or plausibility designs. For evaluating large-scale interventions, studies with plausibility designs are often the only feasible option and may provide valid evidence of impact. There is an urgent need to develop evaluation standards and protocols for use in circumstances where RCTs are not appropriate.

How can we achieve and maintain high-quality performance of health workers in low-resource settings?

In low and middle income countries, health workers are essential for the delivery of health interventions. However, inadequate health-worker performance is a very widespread problem. We present an overview of issues and evidence about the determinants of performance and strategies for improving it. Health-worker practices are complex behaviours that have many potential influences. Reviews of intervention studies in low and middle income countries suggest that the simple dissemination of written guidelines is often ineffective, that supervision and audit with feedback is generally effective, and that multifaceted interventions might be more effective than single interventions. Few interventions have been evaluated with rigorous cost-effectiveness trials, and such studies are urgently needed to guide policy. We propose an international collaborative research agenda to generate knowledge about the true determinants of performance and about the effectiveness of strategies to improve performance. Furthermore, we recommend that ministries of health and international organisations should actively help translate research findings into action to improve health-worker performance, and thereby improve health.

Rapid growth in infancy and childhood and obesity in later life--a systematic review.

The association between obesity and morbidity resulting from chronic diseases is well known. This systematic review addresses studies of the role of rapid growth in infancy and childhood as possible determinants of overweight and obesity later in the life course. We reviewed MEDLINE for studies reporting on growth in infancy and childhood, as well as measures of weight or adiposity in later childhood, adolescence or adulthood. The methodological quality of the papers was assessed using the criteria suggested by Downs and Black. Sixteen articles that fulfilled review criteria were located. There was wide variability in the indicators used for defining rapid growth as well as overweight or obesity. The age range in which weight or adiposity was measured ranged from 3 to 70 years. In spite of differences in definitions used, 13 articles that reported on early rapid growth found significant associations with later overweight or adiposity. Efforts should be made to standardize the definition of rapid growth, as well as that of overweight and obesity in children and adolescents. The most frequent definition for rapid growth in this review was a Z‐score change greater than 0.67 in weight for age between two different ages in childhood. Regarding obesity, the definition proposed by the International Obesity Task Force also appears to be most appropriate. The present results indicate that early growth is indeed associated with the prevalence of obesity later in the life course.

Worldwide Timing of Growth Faltering: Revisiting Implications for Interventions

OBJECTIVE: Our goal was to describe worldwide growth-faltering patterns by using the new World Health Organization (WHO) standards. METHODS: We analyzed information available from the WHO Global Database on Child Growth and Malnutrition, comprising data from national anthropometric surveys from 54 countries. Anthropometric data comprise weight-for-age, length/height-for-age, and weight-for-length/height z scores. The WHO regions were used to aggregate countries: Europe and Central Asia; Latin America and the Caribbean; North Africa and Middle East; South Asia; and sub-Saharan Africa. RESULTS: Sample sizes ranged from 1000 to 47 000 children. Weight for length/height starts slightly above the standard in children aged 1 to 2 months and falters slightly until 9 months of age, picking up after that age and remaining close to the standard thereafter. Weight for age starts close to the standard and falters moderately until reaching approximately −1 z at 24 months and remaining reasonably stable after that. Length/height for age also starts close to the standard and falters dramatically until 24 months, showing noticeable bumps just after 24, 36, and 48 months but otherwise increasing slightly after 24 months. CONCLUSIONS: Comparison of child growth patterns in 54 countries with WHO standards shows that growth faltering in early childhood is even more pronounced than suggested by previous analyses based on the National Center for Health Statistics reference. These findings confirm the need to scale up interventions during the window of opportunity defined by pregnancy and the first 2 years of life, including prevention of low birth weight and appropriate infant feeding practices.

Chronic obstructive pulmonary disease in five Latin American cities (the PLATINO study): a prevalence study

BACKGROUND Both the prevalence and mortality attributable to chronic obstructive pulmonary disease (COPD) seem to be increasing in low-income and middle-income countries, but few data are available. The aim of the PLATINO study, launched in 2002, was to describe the epidemiology of COPD in five major Latin American cities: São Paulo (Brazil), Santiago (Chile), Mexico City (Mexico), Montevideo (Uruguay), and Caracas (Venezuela). METHODS A two-stage sampling strategy was used in the five areas to obtain probability samples of adults aged 40 years or older. These individuals were invited to answer a questionnaire and undergo anthropometry, followed by prebronchodilator and postbronchodilator spirometry. We defined COPD as a ratio less than 0.7 of postbronchodilator forced expiratory volume in the first second over forced vital capacity. FINDINGS Complete information, including spirometry, was obtained from 963 people in São Paulo, 1173 in Santiago, 1000 in Mexico City, 885 in Montevideo, and 1294 in Caracas. Crude rates of COPD ranged from 7.8% (78 of 1000; 95% CI 5.9-9.7) in Mexico City to 19.7% (174 of 885; 17.2-22.2) in Montevideo. After adjustment for key risk factors, the prevalence of COPD in Mexico City remained significantly lower than that in other cities. INTERPRETATION These results suggest that COPD is a greater health problem in Latin America than previously realised. Altitude may explain part of the difference in prevalence. Given the high rates of tobacco use in the region, increasing public awareness of the burden of COPD is important.

Applying an equity lens to child health and mortality: more of the same is not enough

Gaps in child mortality between rich and poor countries are unacceptably wide and in some areas are becoming wider, as are the gaps between wealthy and poor children within most countries. Poor children are more likely than their better-off peers to be exposed to health risks, and they have less resistance to disease because of undernutrition and other hazards typical in poor communities. These inequities are compounded by reduced access to preventive and curative interventions. Even public subsidies for health frequently benefit rich people more than poor people. Experience and evidence about how to reach poor populations are growing, albeit largely through small-scale case studies. Successful approaches include those that improve geographic access to health interventions in poor communities, subsidized health care and health inputs, and social marketing. Targeting of health interventions to poor people and ensuring universal coverage are promising approaches for improvement of equity, but both have limitations that necessitate planning for child survival and effective delivery at national level and below. Regular monitoring of inequities and use of the resulting information for education, advocacy, and increased accountability among the general public and decision makers is urgently needed, but will not be sufficient. Equity must be a priority in the design of child survival interventions and delivery strategies, and mechanisms to ensure accountability at national and international levels must be developed.

Countdown to 2015 decade report (2000–10): taking stock of maternal, newborn, and child survival

The Countdown to 2015 for Maternal, Newborn, and Child Survival monitors coverage of priority interventions to achieve the Millennium Development Goals (MDGs) for child mortality and maternal health. We reviewed progress between 1990 and 2010 in coverage of 26 key interventions in 68 Countdown priority countries accounting for more than 90% of maternal and child deaths worldwide. 19 countries studied were on track to meet MDG 4, in 47 we noted acceleration in the yearly rate of reduction in mortality of children younger than 5 years, and in 12 countries progress had decelerated since 2000. Progress towards reduction of neonatal deaths has been slow, and maternal mortality remains high in most Countdown countries, with little evidence of progress. Wide and persistent disparities exist in the coverage of interventions between and within countries, but some regions have successfully reduced longstanding inequities. Coverage of interventions delivered directly in the community on scheduled occasions was higher than for interventions relying on functional health systems. Although overseas development assistance for maternal, newborn, and child health has increased, funding for this sector accounted for only 31% of all development assistance for health in 2007. We provide evidence from several countries showing that rapid progress is possible and that focused and targeted interventions can reduce inequities related to socioeconomic status and sex. However, much more can and should be done to address maternal and newborn health and improve coverage of interventions related to family planning, care around childbirth, and case management of childhood illnesses.