Early Childcare use and Adolescent ExternalizinBehaviors in a 17-year Population-Based Propensity Score Study

• In Event: 1-049 - Non-Parental Child Care: An International Perspective on Patterns of Choice and Methods for Analyses

Integrative Statement

Introduction. Child care services during the preschool years provide opportunities for social interactions that may facilitate children’s learning of acceptable social behaviors. Furthermore, child care services may reduce exposure to family adversity for some children. A previous study in the Québec Longitudinal Study of Child Development showed that children of mothers with low levels of education exposed to early child care exhibited substantially lower levels of physical aggression at 5 years of age (Côté et al., 2007). However, it is unknown whether these beneficial effects of child care extend to adolescence. The objective of this study was to determine whether intensity of exposure to preschool child care has a long-term beneficial effect on externalizing behaviors in adolescence.
Hypothesis. We hypothesized that (1) children attending child care would show fewer externalizing behavior problems in adolescence, and (2) this effect would be more pronounced for children from low socioeconomic families.
Study population. N=1588 participants form the Québec Longitudinal Study of Child Development were followed-up yearly or bi-yearly from 5 months to 17 years.
Methods. From 5 months to 5 years of age mothers reported the intensity of child care exposure (i.e., number of hours per week of child care attendance), which was modeled as low, moderate or high trajectories of exposure (Figure 1). Main outcomes were self-reported physical aggression, opposition, hyperactivity, and impulsivity symptoms (12-17 years). Family socioeconomic status was measured at 5 months. We used propensity score weights (PSW) to balance exposed and unexposed children’s and family’s measured background characteristics explaining differences in child care use. Additionally, sensitivity analyses based on the E-value and expressed in a risk ratio scale (VanderWeele & Ding, 2017) were reported in order to evaluate the potential impact of unmeasured characteristics that may threaten causal inference.
Results. PSW reduced the background differences between children with different child care intensity exposures, although not in an equally successful way for all background factors (Figure 2). Children exposed to moderate intensity of child care had lower physical aggression and opposition scores compared to those exposed to low intensity of child care. A significant child care by socioeconomic status interaction (P=0.017) indicated that, for adolescent physical aggression, the effect was specific to children from low socioeconomic status families (B=-0.33, SE=0.11, d=-0.32, P=0.002), while for opposition the effect was similar across socioeconomic status categories (B=-0.22, SE=0.10; d=-0.22, P=0.029). Sensitivity analyses indicated that those observed effects could be explained away by an unmeasured confounder that was associated with both the treatment and the outcome by a risk ratio of 1.7-fold (for opposition) and 2.1-fold (for physical aggression) each, above and beyond the confounders accounted for by the PSW. These findings suggested that moderate intensity of exposure to early child care services (vs low intensity) conferred protection against manifestations of externalizing behavior problems during adolescence. The findings were moderately robust to potential unmeasured confounding over and beyond those accounted for by our propensity-score design. Population-based child care services may represent a public health prevention strategy, especially for disadvantaged children.

Authors

• Massimiliano Orri, McGill University
  Presenting Author

• Sylvana Côté, University of Montreal
  Non-Presenting Author