Methods: This analysis used data from a longitudinal study of services and outcomes for a sample group of children who had a first report for abuse or neglect in 1993-1994. Two subgroups were formed: (1) children in a family receiving Aid to Families with Dependent Children (AFDC) (the “low-income group”, N=6,889); and (2) the remainder of children of the same birth years with no record of AFDC during that time (the “comparison group”, N=1,870). Census tracts (N=323) served as a proxy for neighborhood, with an average of 21 families per tract. Intraclass correlation (ICC) was used to develop the rationale for a multilevel model. Multilevel modeling predicted age of onset as a continuous variable then longitudinal growth models predicted yearly risk for maltreatment reports through age 18.
Results: The ICC for neighborhood predicting age of onset was .017. The low-income group had an age of onset 2 years younger than the comparison group, controlling for parent's age, education, and neighborhood income. The growth model analysis indicates that before age one, the low-income group has a 7.2% probability of a report compared to 2.3% in the comparison group. For both groups, the risk for maltreatment increases until age 7-8, then decreases until age 18. The risk disparity between the two groups is highest during infancy and late adolescence when children in the low-income group are about three times more likely to have a report of maltreatment.
Discussion: The ICC suggests that 2% of the variance in age of onset is explained by neighborhood. This finding is similar to Coulton et al. (1999) predicting Child Abuse Potential scores (2-5%) and Molnar et al. (2003) predicting parent to child physical aggression (2%). Low-income families have an earlier onset of maltreatment, providing support for home visitation prevention programs targeting these families. During grade school, there may be protective factors that level the risk experienced by children based on income. During infancy and high school, these protective factors seem to be reduced and the impact of family poverty is greater.