Abstract
BACKGROUND: Accurate concussion monitoring requires access to preinjury baseline data. This is particularly important in adolescent athletes who have a high risk of concussion and are prone to prolonged recovery. As Rugby Union is governed by similar laws for men and women, it is also an ideal population to rigorously examine the impact of biological sex on concussion symptoms. AIMS: To evaluate self-reported concussion symptoms at baseline in adolescent rugby union players, and examine if subtype-specific symptoms are affected by concussion history and biological sex. METHODS: Adolescent rugby union players aged 16-18 years were recruited during the 2022-2023 playing season. Participants completed a series of questionnaires covering post-concussion symptoms, concussion clinical profiles, anxiety, depression and fear avoidance behaviours. Independent variables of interest in analysis were biological sex and concussion history. RESULTS: 149 participants (75% male) were included. 42% (63/149) reported at least one previous concussion (average time since concussion: 18.7 months, range 1-72). Adolescents with a concussion history reported significantly higher scores than those with no history, across two clinical profiles (ocular and sleep), concussion symptom severity, and depression, all based on medium effect sizes (SMD 0.3-0.5). Females had significantly higher scores across cognitive/fatigue, ocular and sleep clinical profiles, concussion symptoms, anxiety and depression, each with large effect sizes (SMD > 0.5). CONCLUSIONS: Concussion history and sex are associated with higher baseline scores on specific concussion clinical profile, concussion symptom severity, and anxiety symptoms. These findings highlight the importance of considering baseline differences when interpreting post-injury clinical profile symptoms in adolescent rugby players. (Trial registration: ACTRN12622000931774).