Longitudinal patterns of behavior, cognition, and quality of life after mild traumatic brain injury in children: BIONIC study findings.

: Research following mild traumatic brain injury (mTBI) during childhood predominantly examines recovery up to 12 months post-injury. : To determine children's longer-term (4 years) patterns and predictors of recovery. : Parents of 196 children (aged 1-15 years) completed the Behaviour Assessment System for Children and Pediatric Quality of Life Inventory at baseline, 1, 6, 12, and 48 months post-injury. Children aged ≥8 years at each assessment completed a computerized neurocognitive testing battery. At 1 month, parents completed the Hospital Anxiety and Depression Scale. Multilevel modeling accounted for repeated measures. : Children had significantly fewer child behavior problems, better adaptability, and improved quality of life after 12 months. Concurrent improvements in overall neurocognitive function were no longer significant once adjusted for age, gender, and socio-economic status. From 12 to 48 months, quality of life reduced significantly while child behavior and neurocognition plateaued. Child behavior problems and worse quality of life were associated with parental anxiety and lower socio-economic satus. : Children's recovery in the year following mTBI appears to plateau from 12 to 48 months, with a concomitant reduction in quality of life. Identification and treatment of parent mental health issues may reduce the exacerbation of negative child outcomes following mTBI.