The risk of mortality in children is linked to their nutritional status, and the proportion of children who die in a population tends to be closely related to the proportion of severely malnourished children. The link between children's mortality and nutrition has been specified by Martorell and Sharma (1985:200) as follows: severe malnutrition impairs children's immunocompetence, and this impaired immune system raises susceptibility to infection and reduces the speed of recovery. It is not malnutrition that causes infection, but an unhygienic environment. When infection occurs in a malnourished host, it is usually severe. Infection, in turn, operates synergistically with malnutrition to determine the rate of recovery or death (Chen, 1988:272). The effect of nutrition on mortality is therefore not direct. Rather, nutritional status serves as a good indicator of a host's resistance to disease and hence is an indirect measure of health (Venkatacharya, 1985:249-250).
Severely malnourished children have been found to have higher rates of death than children who are well nourished. A longitudinal study conducted between 1985 and 1987 in 16 Tanzanian villages (Yambi et al., 1991) found that mortality was highest among children aged 12-18 months and that all anthropometric indicators, height-for age, weight-for-age and weight-for-height, were significant predictors of mortality (Yambi et al., 1991:273). Children who were severely stunted were twice as likely to die as those not stunted. The relative risk was 2.5 times for those who were moderately or severely wasted compared to those that were not. In Matlab, Bangladesh, severely malnourished children between 1981 and 1983 were 9 times more likely to die than those with normal nutritional status (Bhuiya, Wojtyniak and Karim, 1989).
Nutritional studies in Nigeria
There were no known published nutritional data for Ondo State before the report of the ODHS in 1989. For this reason, the review of nutritional studies presented here covers the entire country of Nigeria. Even now, studies on nutritional status using either cross- sectional survey, total community or longitudinal methods are very rare in Nigeria. One
of the earliest was carried out by Nicol (1956). He studied four groups of children from different parts of Nigeria; three groups of farmers' children from Kanuri and Shuwa, Otukwang clan and Kamberi were compared with children of Yoruba and Ibo urban salaried workers. The study showed that, for children of comparable age, the Kanuri and Shuwa children were the tallest among all the children although they were lighter (weight) and thinner (skinfold thickness) than Yoruba and Ibo children. In terms of skinfold thickness, the children of the Otukwang farmers were the fattest (Nicol, 1956:187). Nicol (1956) also reported that the height, weight and skinfold thickness of the Nigerian children were all lower than those of American children and that the calorie requirements of the Nigerian children were higher than those recommended by the Food and Agricultural Organization.
A community nutritional level assessment covering 19 households was conducted in Uboma, Eastern Nigeria, between 1964 and 1965 by the Rockefeller Nutrition Research Team from the University of Ibadan. The study recorded actual weight of foods consumed or the price paid for them in 19 households. The study found that the protein content of the diets was only 8.6 per cent and below the requirement for growing children, adolescents, and pregnant and lactating women. On malnutrition among children in the study area, the team concluded: The high rate of parasitic infestation among Uboma children, combined with the low dietary intakes ... are the potent factors explaining their health and physique' (Dema and Osama, 1966:67). The conclusion of the study agrees with the view of Annegers (1972:213) who attributed the form, incidence and severity of malnutrition among Nigerian children to the long duration of breastfeeding, the low calorie and protein content of the weaning food and the pathological environment.
Morley's (1958:4) study in Ilesha, Western Nigeria, was hospital based. Morley reported that nutritional deficiency accounted for 20 per cent of children admitted to the children's ward in Ilesha from January to July, 1957, and 22 per cent of them died. At a time in 1957, 85 per cent of the admission were suffering from protein malnutrition.
Adekolu-John (1987:118), in a survey on nutritional status among children in the Kainji area of Middle-belt Nigeria, found that males grew generally taller than females; the mean height was 167 cm for males and 159 cm for females and was significant (P < 0.05). The study also showed that malnutrition was inversely related to age. For example, about 20 per cent of under-five children were severely stunted, compared with 10 per cent among those aged 5-9. Fagbule (1990:8) carried out a study of malnutrition among 250 Nigerian children in Ilorin aged between six months and 36 months attending the University of Ilorin Teaching Hospital between September and December, 1985. The author reported that 61 per cent of the malnourished children belonged to mothers with no education, while only seven per cent belonged to women with post primary education. Family instability, poverty and poor environmental sanitation were also associated with malnutrition in the study.
Osinusi and Oyejide (1987) carried out a survey of 208 children aged between 0 and 59 months living in two low socio-economic quarters in Ibadan, Nigeria in 1984. They compared their result with a similar study that had been conducted in the same location in 1968 and observed an improvement in the average weight for age of about 0.4 to 1 kilogram, but no improvement in height for age of under-five children over the period in the study locations. The survey by Ebomoyi, Wickremasinghe and Cherry (1991) showed the effect of environment (ecological zones) on school-age children (aged 6-15) in the savanna area of the Middle-belt, Nigeria. Using Quetelet's index7, the study observed that children in grassland savanna had poorer nutritional status than those in wooded areas. Unfortunately, Ebomoyi et al. did not analyse their data by any socio economic variables, which makes it difficult for their findings to be compared with the results of other studies in Nigeria.
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' The Quetelet index is calculated as (weight/height ). It was named after the man who invented it in the
second half of the 19th century (Quetelet, 1869 cited in Cole, 1991:87-88). It is otherwise known as body mass index (BMI)
Examining the relationship between child nutritional status and diarrhoea in a rural area of Northern Nigeria, Tomkins (1981:860-862) observed that the frequency of diarrhoea attack was not significantly higher among children with a low weight-for-age (underweight) and those with a low height-for-age (stunting). However, children who were low in weight-for-height (wasting) experienced 47 per cent more episodes of diarrhoea than children who had normal weight-for-height. Tomkins defined underweight children as those weighing below 75 per cent of the normal weight-for age, stunted children as those below 90 per cent of normal height-for-age and wasted children as those below 80 per cent of normal weight-for-height. His study supports the view that malnutrition increases the severity of diarrhoea.
This review of nutritional studies in Nigeria suggests that the degree of malnutrition is related to child's age, child mortality rate and incidence of diarrhoea. In the section that follows, a fuller description of the covariates of childhood nutrition is presented.
Correlates of childhood nutrition
Studies on children's nutritional status and socio-economic variables have often found contradictory results depending on the type of analysis and data collection approach. In Bamako, Mali, Dettwyler (1986:651) studied 136 children between 1982 and 1983 and reported that socio-economic status of family did not account for variations in the nutritional status of children. The qualitative component of the study provided some reasons for this. For example, parents believed that a child needed no solid food before the eighth month of life and, apart from putting food before them so that the children could help themselves if they felt so inclined, the parents made no attempt to encourage their children to eat (Dettwyler, 1986:658-660). Similarly, Christian et al. (1988) carried out a study in rural Panchmahal, India, to examine the relationship between maternal literacy and child nutrition but observed no significant relationship between the two variables.
In contrast, using height-for-age as an indicator to examine the differentials in children's anthropometric status in 19 countries, Sommerfelt (1991:986) found a direct relationship between maternal education and children's nutritional status, worse nutritional status in rural than in urban areas, and a greater mean height among children in households with piped water than among others with no indoor piped water. Rural- urban differences persisted in ten countries even after controlling for other independent variables, and maternal education was similarly significant in 11 countries. The study by Sommerfelt (1991:993) included Ondo State data. An examination of her results for Ondo State showed that maternal education was not significant in multivariate analysis, but place of residence was. Ruel et al. (1992:909) focused on the role of maternal nutritional knowledge in Lesotho and found that it was a significant predictor of child nutritional status only in wealthier households. This suggests that knowledge alone cannot ensure adequate nutritional status among children if there is no access to the resources needed to provide adequate food supply.
A thorough review of available evidence on the relationship between maternal employment status and childhood nutrition showed that the evidence did not suggest any clear-cut pattem (Leslie, 1988:1357-1358). Depending on the variables examined and the analytical tools adopted, different (often contradictory) results were obtained in different parts of the developing world. For example, Powell and Grantham-McGregor (1985) studied 229 low income households in urban Kingston, Jamaica and found that the children of working mothers had poorer nutritional status, although in Western Jamaica Marchione (1980) found that there was no direct relationship between mothers' work status and the nutritional status of their children.
Similarly, Popkin (1980) studied 34 rural barrios in Laguna, Philippines, and, focusing on intra-household issues, found that mothers' employment status had a significant negative effect on the weight-for-age and height-for-age of their children up to age two. A follow-up study which did not focus on intra-household issues found no significant relationship between mothers' labour force participation and the nutritional status of
their children. The only finding that cut across cultural boundaries was that working mothers tended to mix breastfeeding with bottlefeeding earlier than their non-working counterparts.
The need for supplementary qualitative data
This review indicates that the processes through which cultural and socio-economic factors metamorphose to influence the effects of the proximate variables on infant and child mortality and nutrition are yet to be clearly understood. A number of inconsistencies remain unresolved. According to Trussed and Menken (1984:341), the research emphasis so far has been on analysing existing data that were not collected as part of any true experiment, although true experiment is not possible in demography. Therefore, they argued that it has not been possible to identify determinants, but merely covariates. They concluded that an understanding of the intricate mechanisms would not come through the 'application of ever more sophisticated statistical analysis', such as the multi-stage equation suggested by Stolnitz (1983), but from appropriately designed research and data collection methods. Mosley and Chen (1984:29) also noted that the multifactorial nature of child survival creates a mesh of interlocking causes that tends to defy sequestered quantification. Thus, the call is still being made for more in-depth, micro-studies using anthropological methods as a way of placing findings from large- scale demographic surveys in context (Caldwell, 1984:106-109; 1990:xiii; Caldwell et al., 1990; United Nations, 1984:6-7; Chen, 1988:263-264; Feyisetan, 1988:7.2.40- 7.2.44; Reddy, 1990; Cantrelle and Locoh, 1990). This study is an endeavour in this direction.
Structure of the thesis
Chapter 2 discusses the methodology of the data used in this thesis, and gives an assessment of the data quality and a brief introduction to the location of study, Ondo State. Chapter 3 initiates the discussion of the findings of the thesis. Following the Mosley and Chen (1984) analytical model, the chapter discusses the socio-economic
covariates of infant mortality. Chapter 4 examines the proximate determinants through which socio-economic and other background variables are expected to affect child survival. After this, Chapter 5 opens a window on the health status of surviving children by using anthropometric data to assess the health status of children aged 6-36 months. Chapter 6 discusses the behavioural aspects of health by using qualitative data to give context to all the patterns observed in quantitative analyses. The last chapter contains a summary of findings and some recommendations based on lessons from a synthesis of macro and micro approaches.
Chapter 2
INTRODUCTION TO STUDY AREA, METHODOLOGY AND ASSESSMENT