Concussion in Spanish Rugby Union ( <scp>XV</scp> ): A National Analysis of Incidence, Burden, and Determinants of Return to Play

Sport-related concussion (SRC) is one of the most frequent injuries in rugby union and remains a public health concern owing to short-, medium-, and long-term consequences. Although SRC epidemiology is well described internationally, national data from Spanish rugby union are lacking. A census-based surveillance study was conducted across one competitive season including all official matches from the men's senior (División de Honor), women's senior (Liga IBERDROLA), and men's under-23 (CNM23) competitions. SRC was defined according to the 6th International Consensus on Concussion in Sport and all matches were conducted in accordance with World Rugby's Recognize and Remove protocol. Case identification combined medical reporting with independent video review. Incidence and burden were calculated per 1000 player-match-hours (PMH). Time to graduated return-to-play (GRTP) was analyzed using Kaplan-Meier methods, and determinants of GRTP duration were examined using Gamma regression. Across 317 matches (12 680 PMH), 80 SRCs were identified, giving an incidence of 6.31/1000 PMH (95% CI, 4.9-8.0). Incidence was highest in División de Honor, followed by Liga IBERDROLA and CNM23 (p < 0.001). Burden was 92 days lost/1000 PMH. Median GRTP duration was 14 days (95% CI: 13.1-14.9), with no differences between competitions or positions. Longer GRTP duration was associated with ruck events, fourth-quarter injuries, sex, and previous SRC history. The incidence and burden differed by competition level, whereas recovery duration was influenced by match context and intrinsic factors. The GRTP durations observed suggest variability in protocol implementation and highlight the need for consistent supervision, following ruck-related and late-match injuries. Findings support individualized GRTP pathways to optimize return-to-play outcomes.