Objective To predict the number of days removed from sport following a diagnosed concussion in middle school aged children using the Child Sport Concussion Assessment Tool 5^th Edition (Child SCAT5).

Design Retrospective cohort.

Setting Sixteen middle schools within one large public school system.

Participants 34 middle school age athletes (age=11–13 years, M=12.8, SD=0.86; 61.8% boys, 38.2% girls) diagnosed with a concussion during sport participation.

Outcome Measures Certified athletic trainers administered the Child SCAT5 upon suspicion of a sports-related concussion. The Child SCAT5 is comprised of the following scores: total symptoms endorsed, total symptom severity, domain (immediate memory, concentration, delayed recall) and composite scores from the Standardized Assessment of Concussion (SAC-C), and stance (double leg, single leg, tandem) and total scores from the modified balance error scoring system (mBESS). Child SCAT5 scores were used to predict the number of days that the participant was removed from participation in sport following their diagnosed sport-related concussion.

Main Results The final model included the severity score for the symptoms of ‘ I feel tired a lot’ and ‘I have difficulty concentrating’ and the total number of symptoms endorsed (R=0.526, R²=0.276, R² _adj=0.204, p=0.20).

Conclusions Child SCAT5 scores only account for 20% of the variance associated with the number of days removed from sport for middle school age athletes following a diagnosed sport-related concussion. Additional clinical measures may provide clinical information to account for the remaining variance associated with post-concussion time loss in middle school age athletes.