Methods: The study sample includes 5,000 children served in a child welfare system. The events of interest are case opening (which signifies the delivery of in-home services), entry into and exit from foster care, case closing, and maltreatment. Each child's level of service (i.e., a case open for services vs. placement into foster care) is measured at 30-day intervals. The pattern of change in the level of services over time is assessed using group-based, latent class models (Nagin 1999). Based on the results of these models, a discrete set of service trajectories is identified. The distinctions between trajectory types are explored by examining the relationship between trajectory group assignment, child attributes, and subsequent maltreatment.
Results: Results suggest the existence of roughly 7 trajectories. For example, the first trajectory, which describes the service experiences for the largest subset of children, is characterized by brief, low-level service use (i.e., no placement into foster care). Other trajectories describe children who are placed at the inception of their service spell. The first of these describes the experiences of children with placement spells lasting between 18 and 36 months, followed by in-home services that last an additional 12 months. Another trajectory is organized around placements that last up to 4 years, although relatively few children follow this path. Long-term in-home services characterizes yet another trajectory. Results also suggest that distribution of children across service trajectories depends on the age of the child. Results also indicate that higher rates of subsequent maltreatment are associated with the shortest trajectory.
Implications: Service histories exhibit complex patterns related to the timing, sequence, and duration of the underlying service events. The findings presented here indicate that recent methodological advances make it possible to extract hidden patterns in the data, opening a new and potentially important line of research. Of particular interest, the data suggest that relatively few children follow the most intense service pathways. However, subsequent maltreatment rates are highest among the children with the briefest overall service histories. The findings also point to ways in which event histories can be arrayed alongside developmental trajectories to determine how the timing of events influences their impact on development and vice versa.