Short Normal Children and Environmental Disadvantage: A Longitudinal Study of Growth and Cognitive Development from 4 to 11 Years

Abstract

The aim of this investigation was to follow up a sample of exceptionally short but medically healthy children, and a normal comparison group, previously studied at 4 years of age. They lived in an inner-city area which was, on objective criteria, seriously disadvantaged in socioeconomic terms. When first seen at 4 years, cases were significantly impaired in cognitive abilities relative to comparisons, although firstborns were much less severely affected. Of the original 46 cases, 45 were assessed again at 11 years. Most continued to live in the same geographical area. Case children remained exceptionally short, even when parental stature was taken into account, although a degree of catch-up had occurred. One third had special educational needs, and a similar proportion had been referred for speech therapy. Verbal and nonverbal cognitive skills of both case and comparison children had, on the whole, changed little and group differences persisted. In conclusion, short normal children from socioeconomically disadvantaged backgrounds are at high risk of educational failure at elementary school.

Cognitive and Educational Attainments at School Age of Children Who Failed to Thrive in Infancy: A Population‐based Study

“…The studies of Dowdney et al (1987Dowdney et al ( , 1998 found deficits at both 4 years and 11 years, but the effect size (d, the case-control mean difference divided by the control SD) was smaller at 11 than at 4 (d l 0n82 at 11 and d l 1n36 at 4). This explanation would be compatible with the other results cited above, in which it is generally true that later follow-up is associated with smaller case-control differences, and is not contradicted by any substantial earlier study on children at school age.…”

“…Kelleher et al (1993) found significant differences both in Bayley Scales scores at 12 and 24 months and in cognitive abilities at 3 years using the Stanford-Binet Scales ; but the children in this study were all born preterm, and the cases were on average lighter at birth than the controls, more likely to be born small for gestational age, and more likely to have abnormal or suspect neurological examinations. The children in the Dowdney et al (1987) study have now been followed up at 11 years (Dowdney et al, 1998) and still showed substantial deficits at that age (mean IQ 82n2 for cases and 94n1 for controls). In a follow-up at age 6 of the Skuse et al (1992) case group, however, there was no overall statistically significant difference between cases and controls in McCarthy Scale scores (Boddy, 1997), though there were significant differences in the memory and the quantitative subscales.…”

“…In the one well-designed study to show a clear effect in school age children (Dowdney et al 1987(Dowdney et al , 1998) the case group were specifically identified by poor growth both in weight and height through to age 4, rather than by failure to thrive in infancy as such.…”

“…There is an important distinction between developmental delay in infancy and cognitive deficits in later childhood, however, and the evidence from population-based studies for later deficits is less consistent. Dowdney, Skuse, Heptinstall, Puckering, and Zur-Szpiro (1987) found a very large average deficit of 20n6 points in children 4 years old on the General Cognitive Index of the McCarthy scales (Kaufman & Kaufman, 1977) ; a substantial deficit (11n9 IQ points) was still present in the same children at 11 years (Dowdney, Skuse, Morris, & Pickles, 1998). The case group of Skuse et al (1994) was followed up by Boddy (1997), who found no overall statistically significant difference between the cases and controls on McCarthy Scale scores when they were 6 years old.…”

“…The case definition in Skuse et al (1994) was a weight for age Z (SD) score of k1n88 (3rd centile) or less sustained for 3 months or more by 12 months of age, in infants born at term and with birthweights above the 3rd centile ; in Wilensky et al (1996) it was falling below the 3rd centile in weight for a duration of at least 3 months, in infants born at term and of normal birthweight ( 2500 g). In Dowdney et al (1987Dowdney et al ( , 1998, cases were below the 10th centile for both weight and height at 4 years, and below the 10th centile for weight at the last clinic attendance (usually before 2 years) ; they were selected, therefore, for prolonged poor growth into childhood, rather than failure to thrive in infancy per se. Mitchell et al (1980) used the following criteria to identify their cases : (1) any recorded weight under 24 months of age below 80 % of normal if previous weight was above 80 % ; (2) first recorded weight below 80 % of normal if infant was not noted to be premature ; (3) failure to thrive noted on the problem list or in the clinic notes before 24 months of age.…”