TCCC-ASM in the Russo–Ukrainian War: First Combat Experience as a Factor in the Gap Between Training and Practical Application of Knowledge and Skills Among Mobilized Military Personnel

BackgroundTactical Combat Casualty Care for All Service Members (TCCC-ASM) aims to prepare military personnel to provide self-aid and buddy aid in combat. However, the extent to which acquired competencies are retained and translated into effective action during real combat remains poorly understood. This study evaluated the influence of first combat experience on the practical application of TCCC-ASM among mobilized military personnel during the Russo--Ukrainian War. MethodsA multicohort observational study with a mixed retrospective--prospective design was conducted between August 2022 and May 2026. Data from five independent cohorts were integrated, including educational assessments, structured surveys, operational observations, prehospital medical documentation, medical evacuation records, and rehabilitation data. The primary endpoint was the actual implementation of TCCC-ASM knowledge and skills during first combat experience. Transfer of training into operational practice was quantified using the authors' Training-to-Performance Index (TP-index). ResultsA total of 1,961 participants were included. Although all participants successfully completed TCCC-ASM training, only 539 of 1,082 service members with combat experience (49.8%) subsequently encountered situations requiring the practical application of TCCC-ASM knowledge and skills. Among 327 wounded personnel, self-aid was performed by 71 individuals (21.7%), whereas 78.3% required buddy aid. The TP-index for self-aid was 0.132 (95% confidence interval [CI], 0.104--0.163), indicating a substantial gap between successful training completion and performance under real combat conditions. Major barriers included severe pain, inability to recall procedures, panic reactions, limited visibility, and delayed evacuation. First combat experience was also associated with reassessment of the practical relevance of training and a unanimous demand for refresher training. ConclusionsA measurable gap exists between successful completion of TCCC-ASM training and the practical implementation of acquired competencies during combat. This phenomenon, defined as the \textit{Training-to-Performance Gap}, highlights the limitations of relying solely on educational outcomes when evaluating military medical training. The proposed TP-index provides a quantitative framework for assessing the transfer of training into operational performance and supports the implementation of structured refresher training following first combat experience.