An Investigation Into the Reliability of Self-reported Concussion History in Current Rugby Union Players

Perhaps no issue in sports medicine has attracted so much media attention and academic interest in recent years as the potential long-term neurodegenerative sequelae of sports-related concussion on athlete's brain health. Rugby has a high incidence of concussion. Recent research findings from a cohort of former professional players found that the number of concussions sustained during their professional careers was associated with the rate of diagnosed clinical depression and late-life cognitive impairment. A limitation of these studies is the use of a self-reported history of concussion. The reliability of professional rugby players to recall and self-report concussion history has never been quantified in the literature to date. Imperfect recall can generate bias in epidemiologic studies when the proportion of events recalled is associated with the health end points of interest. Associations observed may be spurious and due to recall bias if athletes differ in their knowledge and recognition of concussion symptomology in a manner that is associated with the health outcome of interest ie. under/overreporting of concussion. It is difficult to estimate the magnitude of the bias in the absence of any "gold-standard" measure of concussion history. Due to these concerns about the quality of self-reported concussion history, the investigators considered that it was important to evaluate the reliability of self-reported concussion history.