A - At least one randomized controlled trial, meta-analysis, or systematic review.
B - At least one cohort comparison, case studies, or other type of experimental study.
C - Expert opinion, experience of a consensus panel.
The body of evidence upon which the current guideline is based includes high levels of evidence (e.g., RCT, meta-analysis) supporting many of the recommendations for the acute assessment and management of concussion/mTBI. Furthermore, there is high alignment across treatment/intervention studies, as well as across different guidelines from other groups, on the acute diagnosis and treatment of mTBI. Due to gaps in research recommendations for the management of persistent symptoms post-injury are primarily supported by expert consensus opinion, due to limited high-quality studies evaluating treatment for persistent symptoms following concussion/mTBI and limited guideline recommendations on chronic management. Nevertheless, while there are limitations to the body of evidence supporting the current guideline, the recommendations listed herein address a large gap in the current literature on treatment following concussion/mTBI. Further research is needed on the effectiveness of treatments or interventions intended to manage persistent symptoms following concussion/mTBI.