Objective To investigate the association between the signs, symptoms and modifiers of concussion and protracted recovery in professional Rugby Union players.

Design Prospective cohort.

Setting The English Premiership (the highest level of competition in England).

Participants 810 professional Rugby Union players over two seasons (2012/13 and 2013/14). 150 players reported 181 concussions for which 100 provided data for this analysis (80 concussions had insufficient follow up and 1 player left the study).

Independent variables Symptoms were grouped into 4 domains (head, cognitive, sleep and neuropsychological) previously demonstrated to have adequate internal consistency (Pardini et al., Brit J Sports Med: 38, 661–662, 2004). Symptom burden and standardised assessment of concussion (SAC) scores alongside signs and modifiers (amnesia, loss of consciousness, previous concussion history and balance error score) were also reported.

Dependent Variable Time (days) to return to play (RTP). Protracted recovery was defined as >14 days.

Main results Eighteen percent of players did not RTP within 14 days. Higher symptom burden (OR 1.17, 95% CI 1.01–1.31) and higher balance error scores (OR 1.33, 95% CI 1.06–1.66) were associated with protracted recovery. A higher number of self-reported ‘head cluster’ symptoms were associated with a shorter (<14 days) recovery time (OR 0.90, 95% CI: 0.82–0.98).

Conclusions Clinicians should pay particular attention to higher symptom burden and balance error scores as part of a multimodal assessment to aid early identification of protracted recovery. The association between balance and protracted recovery suggests that targeted rehabilitation programs to improve the vestibular system warrant further investigation.

Competing interests Dr. Matthew Cross – Employed by the Rugby Football Union who part funded the PhD (stipend and fees) that this study was part of

Dr. Keith Stokes – Receives research funding from the Rugby Football Union

Dr. Simon Kemp – Employed by the Rugby Football Union

Dr. Andy Smith – Employed by Premiership Rugby who part funded the PhD (stipend and fees) that this study was part of

Dr. Grant Trewartha – Receives research funding from the Rugby Football Union