Childhood severe traumatic brain injury (TBI) is a leading cause of long-lasting acquired disability, but predicting long-term functional outcome remains difficult.

This study aimed to 1) describe the functional outcome at 1 and 7 years post-TBI; 2) determine the initial and concurrent factors associated with long-term outcome; and 3) evaluate the predictive value of functional status, overall disability level and intellectual ability measured at 1 year post-injury to determine 7-year clinically meaningful outcomes.

Among the children (<16 years) consecutively included over 3 years in the Traumatisme Grave de l'Enfant (TGE) prospective longitudinal cohort study after accidental severe TBI, we studied the outcomes of 39 survivors at 1 and 7 years post-injury. Overall outcome included disability level (Glasgow Outcome Scale), functional status (Pediatric Injury Functional Outcome Scale), intellectual ability (Wechsler scales), executive functions (Behavior Rating Inventory of Executive Functions), behavior (Child Behavior Checklist) as well as neurological impairments and academic status.

Mean (SD) age of the 39 survivors at injury was 7.6 (4.6) years, and long-term evaluation was conducted at a mean of 7.8 years post-injury (range 5.9–9.3); 36% of participants were adults (≥18 years old). Most of the neurological impairments remained stable beyond 1 year after TBI, whereas overall disability level improved significantly from 1 to 7 years but remained highly variable, with almost half of participants presenting significant disability levels (moderate: 26%, or severe: 21%). Almost half of participants had significant cognitive, behavior and/or academic difficulties at 7 years post-TBI. On multivariate regression analysis, functional impairment at 1 year was the best predictor of severe disability at 7 years (F_(3,31)=13.18, p < 0.001, sensitivity=100%, specificity=78%).

Our results confirm the significant long-term impact of childhood severe TBI. All children with TBI should benefit from systematic follow-up, especially those with persistent functional deficits at 1 year post-injury, because the severity of functional impairment at 1 year seems the best predictor of long-term significant disability up to 7 years post-TBI.