Do area characteristics predict change in moderate-to-vigorous physical activity from ages 11 to 15 years?

In light of geographical and epidemiological research suggesting that the socioeconomic environment beyond the family may influence children's physical activity, this study investigated the extent to which neighbourhood socioeconomic conditions predict change in physical activity from ages 10 through 15 years, controlling for the attributes of the individual child and family. Data came from 889 children participating in the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development cohort study. Accelerometers measured Moderate-to-Vigorous Physical Activity (MVPA) during the week and weekend, when the children were aged 10, 11, and 15 years. Selected US census block variables were used to create 'independent' area measures of economic deprivation and social fragmentation scores for child's area of residence at age 10 years. Also, parents' perception of neighbourhood social cohesion was measured in terms of relationships with neighbours. All analyses controlled for participant characteristics: gender, ethnicity, household income-to-needs ratio, maternal education, and for United States region of residence. Growth curve analyses indicated that whereas social fragmentation did not predict MVPA over time, greater area deprivation at age 10 years was associated with lower weekday MVPA for boys at 10 years (β=-0.5, p=0.03) and these differences persisted to age 11 and 15 years. This relationship was reversed for girls. Weekend MVPA was not significantly associated with the level of deprivation in the place of residence at age 10 years. Although the census measure of social fragmentation in the area of residence showed no significant association with MVPA, parent-reported neighbourhood social cohesion was positively associated with weekday (β=2.0, p<0.01) and weekend (β=3.1, p<0.01) MVPA minutes across time. This association was most pronounced for boys. Area level factors may be determinants of physical activity among children and youth in complex ways and parental perception of area social environment may be as important for children's activity levels as 'independently assessed' socioeconomic conditions.