Is the wealth index a proxy for consumption expenditure? A systematic review.

BACKGROUND: Many epidemiological studies require a measure of socioeconomic position. The monetary measure preferred by economists is consumption expenditure; the wealth index has been proposed as a reliable, simple alternative to expenditure and is extensively used. METHODS: A systematic review was conducted of the agreement between wealth indices and consumption expenditure, summarising the agreement and exploring factors affecting agreement. RESULTS: Seventeen studies using 36 datasets met the inclusion criteria. Of these, 22 demonstrated weak agreement, 10 moderate agreement, and four strong agreement. There was some evidence that agreement is higher: in middle-income settings; in urban areas; for wealth indices with a greater number of indicators; and for wealth indices including a wider range of indicators. CONCLUSIONS: The wealth index is mostly a poor proxy for consumption expenditure.

Hb A1c in relation to intrauterine growth among male adolescents in southern Brazil.

The fetal origins hypothesis states that nutritional deprivation in utero affects fetal development and contributes to the incidence of diseases associated with the metabolic syndrome in later life. This study investigated whether haemoglobin (Hb) A(1c), an indicator of blood glucose, varied among healthy male adolescents according to their fetal growth rate, in a middle-income setting. Participants were men aged 18 years, belonging to the 1982 Pelotas birth cohort. Complete data, including gestational age and Hb A(1c) at age 18 years, were available for 197 individuals. There was an inverse association between mean Hb A(1c) and birthweight for the gestational age, but not birthweight alone. The association remained significant after adjustment for family income and mother's education, as well as for body mass index at 18 years (P for trend=0.01 and 0.03, respectively).

Risk factors for injuries in young children in four developing countries: the Young Lives Study.

OBJECTIVE: To assess the occurrence of child injury in four developing country settings and to explore potential risk factors for injury. METHODS: Injury occurrence was studied in cohorts of 2000 children of age 6-17 months at enrolment, in each of Ethiopia, Peru, Vietnam and India (Andhra Pradesh). Generalized estimating equation models were used to explore potential risk factors for child injury. RESULTS: Occurrence of child injury was high in all countries. Caregiver depression emerged as a consistent risk factor for all types of injury measured (burns, serious falls, broken bones and near-fatal injury) across all countries. Other risk factors also showed consistent associations, including long-term child health problems, region of residence and the regular care of the child by a non-household member. CONCLUSIONS: This report provides further evidence of the importance of childhood injury in developing countries and emphasizes the importance of including infants in injury research and prevention strategies. It provides strong evidence of an association between caregiver mental health and child injury risk and contributes to the limited knowledge base on risk factors for child injury in developing countries.

Determinants of mental and motor development at 12 months in a low income population: a cohort study in northeast Brazil.

AIM: To identify biological and environmental factors associated with poorer mental and motor development at age 12 mo in urban communities in northeast Brazil. METHODS: A cohort of 245 infants born during January August 1998 in six hospitals in the interior of Pernambuco was followed twice weekly from birth until 12 mo of age. Socio-economic, demographic and environmental data were collected, together with daily information on morbidity and feeding patterns. Gestational age, birth anthropometry and nutritional status at 12 mo were measured. Multiple linear regression analysis was used to identify variables that had independent effects on mental and motor development assessed at 12 mo of age with the Bayley Scales of Infant Development. RESULTS: Environmental factors explained about 21% and 19% of the variance in mental and motor development, respectively. Of these, the most important were poverty-related. Significant biological factors associated with mental development were birthweight and infant sex. For motor development, the biological factors were weight-for-age and haemoglobin concentration. Biological factors explained only 6% and 5% of the variance in mental and motor development, respectively. CONCLUSION: Of the variables examined, environmental factors had a greater detrimental effect on child development than biological factors in this population. Interventions that enhance social capital and alleviate poverty are advocated.

Breastfeeding and early weaning practices in northeast Brazil: a longitudinal study.

OBJECTIVES: To describe breastfeeding practices from 0 to 12 months of age in 4 small towns that are representative of urban northeast Brazil and to identify factors associated with introduction of other milk in the first month of life. METHODS: From January to August 1998, 364 mothers were interviewed at delivery to ascertain antenatal care; delivery room practices; and their intentions regarding breastfeeding, pacifiers, and introduction of water, teas, and other milk. Their perceptions of home support and the advantages of breastfeeding also were assessed. Thereafter, daily information about feeding practices was collected at twice-weekly home visits. When other milk was started, a second interview was conducted to ascertain initial and current breastfeeding problems and use of a pacifier. Reasons for starting other milk were investigated using 5-point Likert scales. RESULTS: Mothers were positive toward breastfeeding, and 99% breastfed their new infant. Few intended to breastfeed exclusively, and in the first week 80% gave water/tea and 56% used a pacifier. The median duration of exclusive breastfeeding was 0 days, and the median age for starting other milk was 24 days. The median duration of breastfeeding was 65 days for mothers who started other milk within 1 month and 165 days for other mothers. After adjustment for confounding variables, the main factors associated with introduction of other milk within 1 month were pacifier use in the first week (odds ratio [OR], 4.01; 95% confidence interval [CI]: 2.07-7.78), intention to start other milk in the first month (OR, 3.79; 95% CI: 1.74-8.24), giving water/tea in the first week (OR, 3.07; 95% CI: 1.56-6.03), and leaving the maternity ward before breastfeeding was started (OR, 2.59; 95% CI: 1.34-5.04). CONCLUSION: Although breastfeeding is common in this community, it rarely is exclusive and takes place for a relatively short duration. Identification of risk factors for early introduction of other milk offers potential avenues for future intervention, including improvement of breastfeeding support in antenatal and maternity services.

Effect of community-based peer counsellors on exclusive breastfeeding practices in Dhaka, Bangladesh: a randomised controlled trial [see commments].

BACKGROUND: Most mothers breastfeed in Bangladesh, but they rarely practise exclusive breastfeeding. Hospital-based strategies for breastfeeding promotion cannot reach them because about 95% have home deliveries. We postulated that with the intervention of trained peer counsellors, mothers could be enabled to breastfeed exclusively for the recommended duration of 5 months. METHODS: 40 adjacent zones in Dhaka were randomised to intervention or control groups. Women were enrolled during the last trimester of pregnancy between February and December, 1996. In the intervention group, 15 home-based counselling visits were scheduled, with two visits in the last trimester, three early postpartum (within 48 h, on day 5, between days 10 and 14), and fortnightly thereafter until the infant was 5 months old. Peer counsellors were local mothers who received 10 days' training. FINDINGS: 363 women were enrolled in each group. Peer counselling significantly improved breastfeeding practices. For the primary outcome, the prevalence of exclusive breastfeeding at 5 months was 202/228 (70%) for the intervention group and 17/285 (6%) for the control group (difference=64%; 95% CI 57%-71%, p>0.0001). For the secondary outcomes, mothers in the intervention group initiated breastfeeding earlier than control mothers and were less likely to give prelacteal and postlacteal foods. At day 4, significantly more mothers in the intervention group breastfed exclusively than controls. INTERPRETATION: Peer counsellors can effectively increase the initiation and duration of exclusive breastfeeding. We recommend incorporation of peer counsellors in mother and child health programmes in developing countries.

Defecation practices of young children in a Peruvian shanty town.

Little is known about feces disposal practices, their determinants and feasibility for change, despite their importance in the control of diarrheal diseases. We report here the results of formative research for the development of an intervention to promote sanitary disposal of feces of young children. The study was conducted in a densely populated shanty town area of Lima, where water and sanitation systems are scarce. In-depth interviews were undertaken with mothers, husbands and community leaders. Group discussions were held with mothers in order to validate findings from the interviews, investigate particular topics further and explore reactions to possible intervention strategies. The principal defecation sites for young children were diapers, potties, the ground in or near the home, the hill, latrines and flush toilets. The main determinants found were the age of the child, the effort required by the method, perceptions of dirtiness and the availability of resources. Almost all children under one year of age use diapers but the high resource cost of diaper washing is a strong motivation for mothers to move their children on as early as possible. Potties were considered the most socially acceptable and 'hygienic' defecation method for children between one and three years of age. Nevertheless, defecation directly onto the ground is common at this age. Potty training is deemed to be quite difficult and the long term achievements are determined by the initial training success. In most cases, the training process is authoritative and inconsistent. The use of latrines and flush toilets is not considered appropriate for children until they are three to four years old. Based on these initial findings, a micro-trial was conducted to assess the feasibility and acceptability of promoting greater use of potties and associated practices. The results of the trial were very encouraging and provided valuable information for the design of a community-wide intervention. Our findings help explain why the emphasis given in most sanitation projects, where efforts have been concentrated on the promotion of latrines, has failed to induce their utilization by small children. Sanitation projects should incorporate interventions that will promote hygienic defecation and stool clearance practices for infants and small children.

Injuries and noncommunicable diseases: emerging health problems of children in developing countries.

The present article identifies, for children living in developing countries, the major causes of ill-health that are inadequately covered by established health programmes. Injuries and noncommunicable diseases, notably asthma, epilepsy, dental caries, diabetes mellitus and rheumatic heart disease, are growing in significance. In countries where resources are scarce it is to be expected that increasing importance will be attached to the development and implementation of measures against these problems. Their control may benefit from the application of elements of programmes directed against infectious, nutritional and perinatal disorders, which continue to predominate.

PIP: This study evaluates the major causes of ill health that are not covered by global health programs among children in developing countries. Assessments are based on a set of death and disability estimates for 1990-2020. Causes of death are classified as 1) infectious, maternal, perinatal and nutritional conditions, 2) noncommunicable diseases, or 3) injuries. Disability-adjusted life years (DALYs) are used in estimates of disease burden. Childhood disease burden in 1990 among regions, age groups, and sex are compared using DALYs per 1000 population and presented in table form. Among childhood disease burdens, infectious, perinatal and nutritional disorders ranked first (72%), followed by noncommunicable diseases (15%) and injuries (13%); these values are significantly higher in developing countries than in developed regions. Furthermore, injuries and noncommunicable diseases--particularly asthma, epilepsy, dental caries, diabetes mellitus, and rheumatic heart disease-- are increasing in prevalence. It has been estimated that in the next two decades the disease burden of injuries will equal or exceed of infectious diseases. This study suggests that strategies used in programs directed against infectious, nutritional and perinatal disorders should be applied to the control of injuries and noncommunicable diseases; it stresses the importance of community involvement, family education, and social marketing in the formulation and implementation of these control measures.

Impact of fly control on childhood diarrhoea in Pakistan: community-randomised trial.

BACKGROUND: Several million children are killed each year by diarrhoeal diseases; preventive strategies appropriate for developing countries are vital. Despite strong circumstantial evidence that flies are vectors of diarrhoeal diseases, no convincing studies of the impact of fly control on diarrhoea incidence in developing countries have been reported. We undertook a randomised study of the effect of insecticide spraying on diarrhoea incidence. METHODS: Six study villages were randomly assigned to two groups. Flies were controlled through insecticide application in group A in 1995 and in group B in 1996. In 1997 the effectiveness of baited fly traps was tested in group A villages. Diarrhoea episodes were monitored in children under 5 years through mothers' reports during weekly visits by a health visitor. Fly density was monitored by use of sticky fly-papers hung in sentinel compounds. FINDINGS: During the fly seasons (March-June) of both 1995 and 1996, insecticide application practically eliminated the fly population in the treated villages. The incidence of diarrhoea was lower in the sprayed villages than in the unsprayed villages in both 1995 (mean episodes per child-year 6.3 vs 7.1) and 1996 (4.4 vs 6.5); the reduction in incidence was 23% (95% CI 11-33, p=0.007). At times other than the fly season there was no evidence of a difference, in diarrhoea morbidity between sprayed and unsprayed villages. Fly density data for 1997 indicate the ineffectiveness of baited traps in this setting. INTERPRETATION: Fly control can have an impact on diarrhoea incidence similar to, or greater than, that of the interventions currently recommended by WHO for inclusion in diarrhoeal disease control programmes in developing countries. This important finding needs confirmation in other settings in developing countries. Technologies and practices that interrupt disease transmission by flies need to be developed and promoted.

PIP: Since circumstantial evidence suggests that flies are vectors of diarrheal diseases, a randomized study of the effect of insecticide spraying upon the incidence of diarrhea was conducted near the town of Peshawar, North West Frontier Province, Pakistan. 6 study villages were randomly assigned to 2 groups, with flies controlled through the twice weekly application of ultra low volume space spraying with insecticide in group A in 1995 and in group B in 1996. The insecticide used was Aqua K-Othrine, a water-based formulation of deltamethrin, applied at a dose of 0.5-1.0 g of active ingredient per hectare by Porta-Pak sprayers. In 1997, the effectiveness of baited fly traps was tested in group A villages. The incidence of diarrhea episodes was monitored in children under age 5 years through mothers' reports during weekly visits by a health worker, and fly density was monitored using sticky fly-papers hung in sentinel compounds. During the fly seasons of March-June in 1995 and 1996, the application of insecticide almost eliminated the fly population in the treated villages. The incidence of diarrhea was lower in the sprayed villages than in the unsprayed villages in both 1995 and 1996, for an overall 23% reduction in incidence. At times other than the fly season, no evidence was observed of a difference in diarrhea morbidity between sprayed and unsprayed villages. Fly density data for 1997 found the baited traps to be ineffective.

Feces, flies, and fetor: findings from a Peruvian shantytown.

Sanitary disposal of feces is vital to combat childhood diarrhea, and its promotion is key to improving health in developing countries. Knowledge of prevailing feces disposal practices is a prerequisite to formulation of effective intervention strategies. Two studies were conducted in a shantytown area of Lima, Peru. First, information was gathered through in-depth interviews with mothers and structured observations (4 hours) of young children and their caretakers. Data on beliefs and practices related to feces disposal behaviors were obtained. Excreta were deposited by animals or humans in or near the house in 82% of households observed. Beliefs about feces depended on their source and were reflected in how likely the feces were to be cleared. While 22% of children aged > or = 18 months were observed to use a potty for defecation, 48% defecated on the ground where the stools often remained. Although almost all children were cleaned after defecation, 30% retained some fecal matter on their body or clothes. Handwashing after the child's defecation was extremely rare for both children (5%) and caretakers (20%). The hygienic disposal of feces poses problems in this type of community. Nevertheless existing practices were found that show promise for promotion on a wider scale, including greater use of potties.

Growth, morbidity, and mortality of children in Dhaka after treatment for severe malnutrition: a prospective study.

Over 1300 severely malnourished children (< 60% of US National Center for Health Statistics weight-for-height, with edema, or both) are admitted each year to the Children's Nutrition Unit in Dhaka. Fatality during treatment is low and recovery is rapid. Our aim was to determine whether this initial success is sustained when children return home. A previous attempt to address this question was frustrated by the difficulty in tracing children after discharge because most are from slum settlements and families move frequently. This prospective study with fortnightly monitoring was therefore undertaken. The main outcomes of interest were anthropometric status, relapse, morbidity, and mortality. Children (n = 437) who had been treated for severe malnutrition when aged 12-59 mo and had reached the discharge criterion of 80% of weight-for-height, were followed for the next 12 mo. During follow-up, 7.5% were lost without trace, 0.6% relapsed, and 2.3% died. Morbidity was high, with a mean of seven episodes of diarrhea during the year. Outpatient visits for diarrhea occurred for 67% of children, and 58% had pneumonia (10% had pneumonia three times). After 12 mo, mean weight-for-height was 91% (-0.92 z score) but mean height-for-age remained at 84% (-4.14 z score). Weight gain, but not height gain, tended to be lower in children who experienced more diarrhea. Fever and cough were not associated with either weight or height gain. The high prevalence of illness highlights the need for continued accessible health care and for interventions to reduce disease acquisition.

Designing educational messages to improve weaning food hygiene practices of families living in poverty.

This paper describes a methodology to design feasible interventions to improve weaning food hygiene practices of families living in extreme poverty. Educational messages to promote specific behavioural changes were defined and tested by utilizing a combination of ethnographic, survey and observational methods, and integrating viewpoints and suggestions of mothers and caretakers into the decision-making process. This new approach culminated in a household trial in which five groups, each of 15 non-practising mothers, were invited to adopt defined behaviours (handwashing before and after defined events, boiling water for reconstituting powdered milk, feeding gruel by spoon rather than bottlefeeding, not storing gruels and milks, and all four together). All initiated the advocated behaviours and most (53-80%) sustained the new behaviours and practised them every time during a one-month period. Of the four advocated behaviours, spoon-feeding was the most difficult to adopt wholly. The methodology was developed in response to the high priority given to reducing weaning food contamination for diarrhoeal disease control, and the lack of any existing methodology for defining appropriate educational interventions in resource-poor regions. This approach, with its combination of qualitative and quantitative methods and community focus, is recommended for future studies to design hygiene and other health education interventions in developing countries.

The role of conceptual frameworks in epidemiological analysis: a hierarchical approach.

BACKGROUND: This paper discusses appropriate strategies for multivariate data analysis in epidemiological studies. METHODS: In studies where determinants of disease are sought, it is suggested that the complex hierarchical inter-relationships between these determinants are best managed through the use of conceptual frameworks. Failure to take these aspects into consideration is common in the epidemiological literature and leads to underestimation of the effects of distal determinants. RESULTS: An example of this analytical approach, which is not based purely on statistical associations, is given for assessing determinants of mortality due to diarrhoea in children. CONCLUSIONS: Conceptual frameworks provide guidance for the use of multivariate techniques and aid the interpretation of their results in the light of social and biological knowledge.

Prevention of diarrhoea in young children in developing countries.

An updated review of nonvaccine interventions for the prevention of childhood diarrhoea in developing countries is presented. The importance of various key preventive strategies (breast-feeding, water supply and sanitation improvements) is confirmed and certain aspects of others (promotion of personal and domestic hygiene, weaning education/food hygiene) are refined. Evidence is also presented to suggest that, subject to cost-effectiveness examination, two other strategies-vitamin A supplementation and the prevention of low birth weight-should be promoted to the first category of interventions, as classified by Feachem, i.e. those which are considered to have high effectiveness and strong feasibility.

PIP: A review of recent evaluations of non-vaccine interventions for the prevention of childhood diarrhea in developing countries both confirmed the importance of standard strategies (e.g., breast feeding, water supply and sanitation improvements) and suggested refinements in approaches to personal and domestic hygiene, weaning education, and food hygiene. Despite the risk of vertical transmission of human immunodeficiency virus in infected areas, the health risks of not breast feeding far outweigh the potential number of lives saved by abandoning this practice. Weaning education programs can produce a 2-12% reduction in diarrhea mortality. Also important is the promotion of food handling, preparation, and storage practices that reduce the risk of fecal contamination. Improvements in water quantity may have a greater impact on diarrhea than improvements in quality alone through their effect on personal and domestic hygiene. Two relatively new strategies, vitamin A supplementation and prevention of low birth weight, should be promoted. Vitamin A intake is significantly associated with both all-cause and diarrhea-specific child mortality; the feasibility of large-scale supplementation programs awaits investigation of their cost-effectiveness, however. The choice of specific diarrheal control strategies depends on local factors such as diarrhea etiologies, the existing infrastructure, and government priorities. In all countries, effective implementation of preventive strategies requires the involvement of a range of sectors (e.g., health, agriculture, water supply, and sanitation).

Controlled trial of three approaches to the treatment of severe malnutrition.

Domiciliary treatment of severely malnourished children could have economic and practical advantages over other methods. We compared three approaches in a controlled trial. 437 children in Dhaka (< 60% weight-for-height, and/or oedema) aged 12-60 months were sequentially allocated to treatment as inpatients, to day-care, or to care at home after one week of day-care. Institutional and parental costs incurred to reach 80% weight-for-height were compared. Costs for inpatient, day-care, and at-home groups averaged 6363, 2517, and 1552 taka (60 taka = UK pound 1). Mortality was low (< 5%) in all three groups. Day-care treatment approached inpatient care for speed of recovery at less than half the cost, but it was unpopular with parents. The at-home group took significantly longer to attain 80% weight-for-height than the other groups, but did so at the lowest average cost. Parental costs were highest for the at-home group as no food supplements were provided; nevertheless this was the most popular option. We conclude that at-home management of severely malnourished children after 1 week of inpatient care is a cost-effective strategy.

Institutional maternal mortality in Mali.

OBJECTIVES: To measure the institutional maternal mortality ratio (MMR) in Mali and suggest ways to reduce it. METHODS: Routinely recorded data from 24 health institutions in three regions were reviewed for 1988 to 1992. RESULTS: The overall MMR in the institutions was 201 maternal deaths per 100,000 live births. Hemorrhage, toxemia and infections accounted for 80% of the 360 recorded maternal deaths, almost all of which were preventable. The main reasons why these conditions result in death lie in poor quality and maldistribution of health services, lack of transport and late use of allopathic services. CONCLUSIONS: Maternal mortality is still a major public health problem in Mali, even among the small proportion of women who reach health facilities. Substantial new initiatives are urgently needed to reduce this major cause of preventable adult female mortality.

Measurement of the frequency and severity of childhood acute respiratory infections through household surveys in northern Ghana.

BACKGROUND: Methodological issues in the design and interpretation of cross-sectional interview surveys of the prevalence of acute respiratory infections (ARI) were assessed among young children. METHODS: A cross-sectional survey was conducted in approximately 20,000 children in the north of Ghana. Approximately half were administered a questionnaire in which the initial questions about recent illnesses were direct questions about the presence or absence of three specific ARI-related symptoms (cough, rapid breathing, difficulty breathing), while the other half were administered a questionnaire which started with an open-ended question on whether the child was ill, designed to elicit spontaneous responses. A 2-week recall period was used in addition to point prevalence questions for half of the children in each group, while 4 weeks was used for the other half. The results were compared with those from a longitudinal morbidity surveillance system in an adjacent population of children. The repeatability of the responses to each of the symptoms/conditions was assessed in a subsample of the children. RESULTS AND CONCLUSIONS: The point and period prevalence rates of ARI symptoms or conditions based on spontaneously elicited responses were more likely to be valid than those based on prompted responses. Furthermore, using a 2-week recall period appeared to give more valid period prevalence rates than a 4-week recall period. The repeatability of the various ARI questions was not high (kappas 0.14 to 0.49), irrespective of the questionnaire design. Whether these findings will also be true in other populations needs to be assessed.