Objective Rugby Union, in common with other elite sports, has developed systems to identify, evaluate and treat players sustaining sports related concussions. This study examines the clinical progress of players following head impact events and investigates which components of the clinical assessment influence a final diagnosis of concussion.

Design Prospective cohort study using logistic regression modelling to determine the predictive value of components of clinical assessments in influencing a final diagnosis of concussion.

Setting Phase 2 of the World Rugby PSCA study between September 2013 and May 2014

Participants Consecutive players sustaining head impact events with the potential for concussion during ten national and international elite adult Rugby Union competitions

Intervention Participants underwent 3 standardised clinical assessments: Initial pitch-side screening; early 3 hours post-match SCAT 3 assessment; and late diagnostic assessment after 2 nights with symptom evaluation and a neuro-cognitive assessment tool.

Outcome measures Diagnosis of concussion determined at the last clinical assessment.

Main results During the 8 months study period 229 players participated in the PSCA process. 130 (56.7%) players were diagnosed with concussion. The 3 hours post-match number of reported symptoms and Standardised Assessment of Concussion (SAC), and the presence of symptoms at 2 nights post injury were independently associated with a final diagnosis of concussion (p<0.05). Other clinical assessments provided no additional prognostic information.

Conclusions The number of symptoms reported and SAC post-match were factors independently associated with a final diagnosis of concussion. Balance tests and severity of post-match symptoms did not appear to provide any additional information in the diagnosis of concussion.

Competing interests None.