Association of externalizing behavior disorder symptoms and injury among fifth graders

Injury is the leading cause of death among American youth, killing more 11-year-olds than all other causes combined. Children with symptoms of externalizing behavior disorders such as attention-deficit/hyperactivity disorder (ADHD) and conduct disorder (CD) may have increased risk. Our aims were to determine: (1) whether increasing symptoms of ADHD and CD associate positively with injuries among a community sample of fifth graders; and (2) whether symptoms of ADHD and CD have a multiplicative rather than additive association with injuries among the sample.

Data were collected from 4745 fifth graders and their primary caregivers participating in Healthy Passages, a multisite, community-based study of pediatric health risk behaviors and health outcomes. The primary outcome was injury frequency. Primary independent variables were ADHD and CD symptoms. Additional covariates included gender, race/ethnicity, and household income. Ordinal logistic regression examined correlates of injury frequency. The interaction between ADHD and CD symptoms also was examined.

In bivariate analyses, the odds of injury increased as ADHD symptoms (odds ratio [OR] 1.29; 95% confidence interval [95% CI] 1.18-1.41) and CD symptoms (OR 1.18; 95% CI 1.07-1.31) increased. However, in multivariate analysis, only ADHD symptoms were significantly associated with injury (OR 1.22; 95% CI 1.10-1.35). There was no statistically significant interaction between ADHD and CD symptoms.

ADHD symptoms are associated with increased odds of injury in fifth graders. Findings have implications for potential injury prevention strategies for mental health practitioners (for example, cognitive training with at-risk youth), pediatricians (ADHD screening), and parents (improved supervision).