Exposure assessment for repeated sub-concussive head impacts in soccer: The HEalth and Ageing Data IN the Game of football (HEADING) study.

The purpose of this paper was to develop exposure estimates for repetitive sub-concussive head impacts (RSHI) for use in epidemiological analyses. We used a questionnaire to collect lifetime history of heading and other head contacts associated with training and playing football from 159 former footballers all members of the English professional football association. We used linear mixed effect regression with player as the random effect, to model the number of headers, blows to the head and head-to-head impacts as a function of potential exposure affecting factors, which were treated as the fixed effects. Exposure affecting factors included playing position, league, context of play (game vs training) and decade of play. Age at time of response to the questionnaire was also included in the models. In model results, playing position was important, with RSHIs being highest among defenders and lowest among goalkeepers. Players headed the ball more during games than in training, and when playing in amateur or youth leagues compared with semi-professional or professional leagues. The average number of reported head impacts declined linearly throughout the observation period (1949-2015). The derived final model for headers explained 43%, 9% and 36% of the between player, within player and total variance in exposure, respectively with good precision and predictive performance. These findings are generally in agreement with previously published results pointing towards the models forming a valid method for estimating exposure to RSHI among former footballers although some further external validation is still warranted.

Acute evaluation of sport-related concussion and implications for the Sport Concussion Assessment Tool (SCAT6) for adults, adolescents and children: a systematic review.

OBJECTIVES: To systematically review the scientific literature regarding the acute assessment of sport-related concussion (SRC) and provide recommendations for improving the Sport Concussion Assessment Tool (SCAT6). DATA SOURCES: Systematic searches of seven databases from 2001 to 2022 using key words and controlled vocabulary relevant to concussion, sports, SCAT, and acute evaluation. ELIGIBILITY CRITERIA: (1) Original research articles, cohort studies, case-control studies, and case series with a sample of >10; (2) ≥80% SRC; and (3) studies using a screening tool/technology to assess SRC acutely (<7 days), and/or studies containing psychometric/normative data for common tools used to assess SRC. DATA EXTRACTION: Separate reviews were conducted involving six subdomains: Cognition, Balance/Postural Stability, Oculomotor/Cervical/Vestibular, Emerging Technologies, and Neurological Examination/Autonomic Dysfunction. Paediatric/Child studies were included in each subdomain. Risk of Bias and study quality were rated by coauthors using a modified SIGN (Scottish Intercollegiate Guidelines Network) tool. RESULTS: Out of 12 192 articles screened, 612 were included (189 normative data and 423 SRC assessment studies). Of these, 183 focused on cognition, 126 balance/postural stability, 76 oculomotor/cervical/vestibular, 142 emerging technologies, 13 neurological examination/autonomic dysfunction, and 23 paediatric/child SCAT. The SCAT discriminates between concussed and non-concussed athletes within 72 hours of injury with diminishing utility up to 7 days post injury. Ceiling effects were apparent on the 5-word list learning and concentration subtests. More challenging tests, including the 10-word list, were recommended. Test-retest data revealed limitations in temporal stability. Studies primarily originated in North America with scant data on children. CONCLUSION: Support exists for using the SCAT within the acute phase of injury. Maximal utility occurs within the first 72 hours and then diminishes up to 7 days after injury. The SCAT has limited utility as a return to play tool beyond 7 days. Empirical data are limited in pre-adolescents, women, sport type, geographical and culturally diverse populations and para athletes. PROSPERO REGISTRATION NUMBER: CRD42020154787.

Inter-identity amnesia for neutral episodic self-referential and autobiographical memory in Dissociative Identity Disorder: An assessment of recall and recognition.

Amnesia is a core diagnostic criterion for Dissociative Identity Disorder (DID), however previous research has indicated memory transfer. As DID has been conceptualised as being a disorder of distinct identities, in this experiment, behavioral tasks were used to assess the nature of amnesia for episodic 1) self-referential and 2) autobiographical memories across identities. Nineteen DID participants, 16 DID simulators, 21 partial information, and 20 full information comparison participants from the general population were recruited. In the first study, participants were presented with two vignettes (DID and simulator participants received one in each of two identities) and asked to imagine themselves in the situations outlined. The second study used a similar methodology but with tasks assessing autobiographical experience. Subjectively, all DID participants reported amnesia for events that occurred in the other identity. On free recall and recognition tasks they presented a memory profile of amnesia similar to simulators instructed to feign amnesia and partial information comparisons. Yet, on tests of recognition, DID participants recognized significantly more of the event that occurred in another identity than simulator and partial information comparisons. As such, results indicate that the DID performance profile was not accounted for by true or feigned amnesia, lending support to the idea that reported amnesia may be more of a perceived than actual memory impairment.

Monitoring the health of transitioning professional footballers: protocol of an observational prospective cohort study.

INTRODUCTION: Transitioning out of professional football is a challenging time in most players' lives. During these preretirement and postretirement years, professional footballers may struggle with their mental, musculoskeletal, neurocognitive and cardiovascular health. Currently, longitudinal data about these health conditions are lacking. This article presents the design of a prospective cohort study with the primary aim of gathering epidemiological evidence about the onset and course of mental, musculoskeletal, neurocognitive and cardiovascular health conditions in professional footballers during their preretirement and postretirement years and evaluating the associations between risk indicators and the health conditions under study in these players. METHODS AND ANALYSIS: An observational prospective cohort study with repeated measurements over a follow-up period of 10 years will be conducted among at least 200 professional footballers (male; 27 (±1) years old). Mental health will be explored by assessing symptoms of distress, anxiety, depression, sleep disturbance, alcohol misuse, drug misuse and disordered eating. Musculoskeletal health will be explored by assessing severe joint injury and related surgery, clinical and radiological osteoarthritis, and joint function (hips, knees and ankles). Neurocognitive health will be explored by assessing the concussion, brain structure and functioning, and neurocognitive functioning. Cardiovascular health will be explored by assessing blood pressure, lipid profile and ECG abnormalities. ETHICS AND DISSEMINATION: Ethical approval for the study was provided by the Medical Ethics Review Committee of the Amsterdam University Medical Centers. The results of the study will be submitted to peer-reviewed journals, will be presented at scientific conferences and will be released in the media (postpublication). TRIAL REGISTRATION NUMBER: The Dutch Trial Registry (Drake Football Study NL7999).

BRain health and healthy AgeINg in retired rugby union players, the BRAIN Study: study protocol for an observational study in the UK.

INTRODUCTION: Relatively little is known about the long-term health of former elite rugby players, or former sportspeople more generally. As well as the potential benefits of being former elite sportspersons, there may be potential health risks from exposures occurring during an individual's playing career, as well as following retirement. Each contact sport has vastly different playing dynamics, therefore exposing its players to different types of potential traumas. Current evidence suggests that these are not necessarily comparable in terms of pathophysiology, and their potential long-term adverse effects might also differ. There is currently limited but increasing evidence that poorer age-related and neurological health exists among former professional sportsmen exposed to repetitive concussions; however the evidence is limited on rugby union players, specifically. METHODS AND ANALYSIS: We present the protocol for a cross-sectional study to assess the association between self-reported history of concussion during a playing career, and subsequent measures of healthy ageing and neurological and cognitive impairment. We are recruiting a sample of approximately 200 retired rugby players (former Oxford and Cambridge University rugby players and members of the England Rugby International Club) aged 50 years or more, and collecting a number of general and neurological health-related outcome measures though validated assessments. Biomarkers of neurodegeneration (neurofilaments and tau) will be also be measured. Although the study is focusing on rugby union players specifically, the general study design and the methods for assessing neurological health are likely to be relevant to other studies of former elite sportspersons. ETHICS AND DISSEMINATION: The study has been approved by the Ethical Committee of London School of Hygiene and Tropical Medicine (reference: 11634-2). It is intended that results of this study will be published in peer-reviewed medical journals, communicated to participants, the general public and all relevant stakeholders.

A video analysis of head injuries satisfying the criteria for a head injury assessment in professional Rugby Union: a prospective cohort study.

OBJECTIVES: Concussion is the most common match injury in professional Rugby Union, accounting for 25% of match injuries. The primary prevention of head injuries requires that the injury mechanism be known so that interventions can be targeted to specifically overall incidence by focusing on characteristics with the greatest propensity to cause a head injury. METHODS: 611 head injury assessment (HIA) events in professional Rugby Union over a 3-year period were analysed, with specific reference to match events, position, time and nature of head contact. RESULTS: 464 (76%) of HIA events occur during tackles, with the tackler experiencing a significantly greater propensity for an HIA than the ball carrier (1.40 HIAs/1000 tackles for the tackler vs 0.54 HIAs/1000 tackles for the ball carrier, incidence rate ratio (IRR) 2.59). Propensity was significantly greater for backline players than forwards (IRR 1.54, 95% CI 1.28 to 1.84), but did not increase over the course of the match. Head to head contact accounted for the most tackler HIAs, with the greatest propensity. CONCLUSIONS: By virtue of its high propensity and frequency, the tackle should be the focus for interventions that may include law change and technique education. A specific investigation of the characteristics of the tackle is warranted to refine the approach to preventative strategies.

The International Rugby Board (IRB) Pitch Side Concussion Assessment trial: a pilot test accuracy study.

BACKGROUND: 'On the field and on the run' assessments of head impact events in professional rugby have resulted in a high proportion of players subsequently diagnosed with confirmed concussion not leaving the field of play at the time of injury. The International Rugby Board (IRB) consequently developed a process to support team doctors in the recognition and management of players at risk of concussion, including development of a multimodal assessment instrument-the Pitch Side Concussion Assessment (PSCA) tool. METHODS: This was a pilot cohort study designed to determine the feasibility of assessing the accuracy of the IRB PSCA tool in elite male rugby. The study population comprised consecutive players identified with a head impact event with the potential to result in concussion during eight international/national competitions. Players were assessed off field by match-day or team doctors, following a temporary substitution. The accuracy of the PSCA tool was measured against a reference standard of postmatch confirmed concussion, based on clinical judgement aided by an established concussion support instrument. RESULTS: A total of 165 head injury events with the potential to cause concussion were included in the study. The PSCA tool demonstrated a sensitivity of 84.6% (95% CI 73.5% to 92.4%) and a specificity of 74% (95% CI 64.3% to 82.3%) to identify players subsequently diagnosed with confirmed concussion. The negative predictive value was 88.1% (95% CI 79.2% to 94.1%); the positive predictive value was 67.9% (95% CI 56.6% to 77.8%). There were no major barriers identified that would prevent the evaluation of the PSCA process or tool in a future large-scale study. CONCLUSIONS: This pilot study has provided the first preliminary estimates for the performance of the PSCA tool, suggesting a potentially favourable balance between positive and negative predictive values. The study has also offered a strong basis to conduct a further larger trial, providing information for sample size calculations and highlighting areas for methodological development.

Press freedom, oil exports, and risk for natural disasters: a challenge for climato-economic theory?

Does the interaction between climactic demands, monetary resources, and freedom suggest a more general relationship between the environmental challenges that human societies face and their resources to meet those challenges? Using data on press freedom (Van de Vliert 2011a), we found no evidence of a similar interaction with natural resources (as measured by oil exports) or risk for natural disasters.

An assessment of training volume in professional rugby union and its impact on the incidence, severity, and nature of match and training injuries.

A prospective cohort study was used to assess the influence of training volume on injuries sustained by 502 professional rugby union players in England. Training volumes (excluding warm-ups, cool-downs, and recovery sessions), player injuries, and player match exposure times were reported weekly. Higher training volumes (>9.1 hours per week) did not increase the incidence of match or training injuries. However, higher training volumes did increase the severity of match injuries, particularly during the second half, and consequently resulted in a significant increase in the number of days' absence due to match injuries. Although lower-limb injuries were the most common match and training injuries, shoulder dislocations/instabilities resulted in more days' absence during weeks of higher training volumes, but the differences were not significant. The least number of days lost due to injuries occurred during weeks of intermediate training volumes (6.2-9.1 h per week). Training volume was not correlated with final league position. Fitness testing, defence, and rucking and mauling components were identified as being very high- or high-risk training activities. Our results provide evidence of the benefits of modifying the volume and content of rugby union training to reduce the risk associated with injuries to professional players.