Description

The RUBYS study is an observational closed cohort conducted over two consecutive competitive seasons (2024-2025 and 2025-2026) in youth rugby players from the RCT (Rugby Club Toulonnais) Association. It focuses on the epidemiology of rugby-related injuries in adolescents enrolled in a structured dual project (school and sport) in the Toulon metropolitan area.

Young players (boys and girls) aged approximately 13 to 18 years, licensed in the RCT Association from the U14 category upwards, benefit from adapted school timetables and regular supervised training sessions. These athletes are monitored medically by the Sports Medicine and Traumatology Unit (UMTS) of the Centre Hospitalier Intercommunal Toulon - La Seyne sur Mer (CHITS), under the responsibility of the principal investigator. All injuries requiring medical consultation are routinely recorded in the Askamon software, which centralizes clinical information, exposure data and follow-up for each player.

The study does not modify usual care and does not introduce any additional medical procedures beyond those required for standard injury management. When an injury occurs, the player is assessed and treated according to usual practice (club doctor, attending physician or emergency services, with referral to specialists and use of imaging or surgery if needed). Information regarding the type of injury, anatomical location, circumstances, and days lost from rugby is recorded as part of routine clinical documentation and sports records (match sheets, training attendance registers), then entered into Askamon. No specific intervention, randomization or additional biological sampling is planned within the framework of this protocol.

For the purposes of the study, a pseudonymized extraction of Askamon will be performed and will include all players with at least one injury requiring medical consultation between August 1, 2024, and June 30, 2026. Each injury event will be considered as an observation, and multiple injuries in the same player will be analysed separately. The dataset will include demographic variables (age, sex), relevant medical history where available, detailed injury characteristics (diagnosis, lesion type, involved body region) and severity expressed as time-loss days until full return to competition. Injuries will be categorized according to international rugby consensus definitions (World Rugby/International Rugby Board \[IRB\]) to ensure comparability with existing literature.

Non-medical variables related to rugby participation will also be extracted: playing position (forwards or backs), competition category, context of occurrence (match versus training), match situation or training drill, recurrence, playing surface (natural or synthetic), type of competition, venue, period of the season, environmental conditions (temperature, weather), equipment (footwear condition) and perceived fatigue where available. These contextual factors will be used to explore potential modifiable risk factors and high-risk situations. The exposure denominator (player-hours) will be estimated from training and match schedules, attendance records and competition data provided by the RCT Association.

The primary analysis will consist of calculating injury incidence rates expressed as the number of injuries per 1000 player-hours of exposure, overall and stratified by sex, age category, playing position and context (training versus match). Secondary analyses will describe the distribution of injuries by type, anatomical site and severity categories, and will assess the relative contribution of different mechanisms and contexts to overall injury burden. Time-loss injuries will be classified into predefined severity grades based on the number of days of absence from full rugby participation, allowing the identification of injuries with the highest impact on players and on team performance.

From a methodological standpoint, the study is primarily descriptive, aiming at providing precise estimates of incidence and severity in the entire eligible population, rather than testing a specific intervention. All eligible players will be included, so no formal a priori sample size calculation is required. The precision of incidence estimates (95% confidence intervals) will be evaluated post hoc according to the actual number of injuries and exposure hours collected. Where appropriate, multivariable models may be used to explore associations between injury occurrence and potential risk factors (e.g. position, age category, match versus training, playing surface), while acknowledging the observational nature of the data and the limitations regarding causal inference.

Participants and their legal guardians will be informed through a written information letter describing the objectives of the research, the nature of the data used, the pseudonymization process and their rights (access, rectification, opposition and withdrawal). Non-opposition from parents or legal guardians is required for inclusion. In case of withdrawal, all data relating to the concerned player will be definitively deleted from the research dataset. No additional burden or constraint is imposed on players, families or staff.

Data will be pseudonymized before analysis, with the identification key kept securely at the Sports Medicine and Traumatology Unit (UMTS) of the CHITS and not available to the statisticians. The dataset will be stored on secure institutional servers, in compliance with applicable regulations on personal data protection. Data will be retained for a limited period (up to 2 years after the last publication, or 3 years after the end of data collection in the absence of publication), then archived for 15 years according to national regulations on clinical research archiving. Results will be disseminated through scientific publications and presentations, with the aim of informing prevention strategies, improving rehabilitation pathways and contributing to safer rugby practice in youth populations.