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Controlling for socio-economic status

No two households will maintain exactly the same per capita income. Moreover, income and wealth are notoriously difficult to measure accurately. Assumptions underlying the concept of positive deviance are that (1) the level of income is more or less the same in very poor neighbourhoods; (2) fairly simple indicators, such as land ownership, housing, and visible possessions can be used to identify families living at approximately the same level of poverty; and (3) additional statistical adjustments made for income can more or less remove its confounding effects.

The studies classified as true positive-deviance research in table 2 did find some variability in family wealth, although they tried to compare homogeneous groups. Morley and associates (1968) concluded, for example, that the fathers of the well nourished were "better farmers" than those of the malnourished. Such variability may be critical to positive deviance when additional small amounts of income are earned by an enterprising mother and used to feed her child.

The point to be made here is that positive-deviance studies must make the attempt to control for socio-economic status. The Kanawati and McLaren (1973) study of failure-to-thrive in Lebanon, for example, was not included in table 2 because large socioeconomic differences were found between the malnourished and well-nourished groups. Given the difficulties of measuring income, total household expenditure is often used as a proxy variable for income and can be analysed by subcategory.

Limiting the number of covariables: restriction by age and topic

As noted many times in this document, an extremely broad range of covariables contribute to child growth amidst poverty. A large number of these interrelate in ways that make it impossible to omit them from consideration without biasing the results of research. Therefore, it is necessary to seek ways to confine research studies in positive deviance to manageable proportions. Studying a narrow age-group is one method of restricting variables that also makes sense from a child-development perspective. Young children change so rapidly that the environmental and behavioural factors that contribute to positive deviance at one developmental stage may differ vastly from those that are important earlier or later. Seven-month-olds have very different needs and characteristics from two-year olds.

Suggested age ranges are: pre-pregnancy; pregnancy; neonates (0 to 1 month); first three months; 4 months until the child starts to crawl; the crawling stage, with its high exposure to dirt from the ground; first walking to start of nutritional recovery (15 to 21 months depending on population): and the early recovery period (21 to 30 months). The exact range should be specified to fit the research question and the location.

Restricting the main topics of investigation to one (or two) item(s), such as breast feeding, is a necessity, although it doesn't remove the need to measure or control for other related factors, such as supplementary food intake, etc.

As with all research on living subjects, it is necessary to ignore factors having effects that are relatively independent of the main relationships being tested by the research study. It is never possible to study or control for all variables.

Rationale for existing behaviours and social structures

Behaviours that appear to have negative effects on the growth and health of young children may serve other purposes related to the survival of the household, or may be caused by constraints that cannot be changed, or by historical developmental disorders within the family that do not respond to short-term programme approaches. Behavioural and social factors that contribute to positive deviance must be tested for transferability before they can be incorporated into programme design. Behavioural trial methods developed by social-marketing and communications professionals are suitable for tests of behaviour-change messages recommended as part of stage 2 in our research model.

Timeline for change

Some factors contributing to positive deviance go back to the childhood of the parents or to earlier circumstances in the history of the parents or to earlier circumstances in the history of the family or the subculture. Cross-sectional research approaches should not ignore these historic factors. Different types of change also require different lengths of time to achieve. Programmatic trials should not assume that attitudes and behaviours that prove resistant in the short run will not yield to change over longer periods.

Nutrition and infection

Because nutrition and infectious illness are so closely related, the resistance of the mother-child dyed to infection. the degree to which the environment exposes the dyed to infection, and the mother and other caretaker's preventive and curative health related behaviours may greatly influence the child's growth status and vice versa.

Aspects of Health Research that are Necessary for Research in Positive Deviance in Nutrition

The mother's overall health-seeking behaviours- how soon she goes for treatment, where, in what order, how persistently she follows treatment instructions, whether administering treatment herself, for the prescribed period, etc. - are topics for research on positive deviance in nutrition. Child-feeding during illness and convalescence belongs to this research domain.

Scrimshaw and Scrimshaw (1980) found, for example, that the mothers in their positivedeviant families persisted in seeking health care for their infants until the child had recovered. They also were more likely to take care of the child personally when he was sick, staying home from income-earning activities in order to do so.

Morbidity cannot be ignored in nutritional studies. Similarly nutritional status cannot be disregarded in morbidity studies. At the very least, the effects of morbidity must be controlled or adjusted for the studies of growth outcome.

The micro-behaviours and environmental factors associated with the transmission and cure of specific diseases fall outside the domain of this paper. A positive-deviance approach should definitely be taken to disease-specific studies of infant and young child morbidity. However' the growth of the child will be a secondary outcome variable in such studies. The primary outcome should be the incidence and duration of the particular infectious illness that is under scrutiny. It is possible and desirable to conduct combined studies of both nutrition and morbidity outcomes. Information for the design of the morbidity component of such studies must be obtained from appropriate medical researchers and epidemiologists.

Checkclist of Nutrition-Infection Relationships

What follows is a checklist of nutrition-infection relationships that are important for the design of research in positive deviance. For the sake of brevity, this checklist is not referenced.

Management of multidisciplinary teams

The different disciplines relating to positive deviance have different vocabularies, theoretical assumptions, and standards for quality control. Therefore, when persons representing these disciplines attempt to work "in committee" the negative aspects of "committee" efforts (slowness, lack of agreement, etc.) are greatly exaggerated. For these reasons it is desirable to have strong leadership for such teams. A strong principal investigator (a single person representing one discipline) should personally integrate the contributions from each discipline into a single study design. Alternately, a strong project director or contract manager with a technical background may provide sufficient leadership to ensure that principal investigators from different disciplines integrate their work effectively.

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