Table 2.

Results of Principal Components Analysis of 5 Neighborhood Sociodemographic Characteristics of 626 Children 2 and 3 Years of Age Born at Very Low Birth Weight^a

Characteristic	Mean (SD)	Range Across Neighborhoods	Item Loadingsb
Neighborhood disadvantage, %
Families living in poverty	8 (10)	0 to 61	0.90
Households with incomes > state median ($69 010)	49 (16)	4 to 88	0.86
Women with a bachelor’s degree	15 (8)	0 to 45	0.70
Single female head of household	3 (3)	0 to 21	0.88
Mothers of young children who were unemployed	4 (4)	0 to 44	0.66
Characteristic	α	Mean (SD)	Range
Neighborhood disadvantage scorec	.86	0 (1)	−2 to 4
Neighborhood disadvantage tertiles, No.
Disadvantaged		221
Middle		167
Advantaged		238

^aVery low birth weight is defined as a birth weight less than 1500 g.

^bItem loadings describe the strength of the relationship between the neighborhood characteristic and the construct of neighborhood disadvantage. Values of more than 0.40 suggest a strong relationship. Factor loadings for women’s education and annual family income represent reverse-coded variables.

^cNeighborhood disadvantage score was created by summing each neighborhood characteristic weighted by its item loading.