. 2009 Mar 18;169(9):1113–1123. doi: 10.1093/aje/kwp021

Table 4.

Principal Components Analysis Factor Loadings for Parental Demographic Variables, Northern California Childhood Leukemia Study, 1999–2007

Variable	Component Loadings
Variable	Parental Socioeconomic Status	Parental Age
Father's education	0.86^a	0.19
Mother's education	0.85^a	0.23
Household annual income	0.81^a	0.20
Father's age	0.27	0.89^a
Mother's age	0.18	0.92^a
Proportion (%) of group variance explained	59	21

A variable was said to load on a given component if the factor loading was ≥0.40.