Nicholson, Susannah E.

Abstract Introduction Combat casualty care requires standardized proficiency criteria to ensure readiness in austere environments, yet gaps persist in defining performance thresholds for critical trauma skills. The Combat Medical Skills Sustainment Consortium (CMSSC), a novel military-civilian collaboration, aimed to validate competency thresholds for 21 Department of Defense-identified trauma skills. Materials and Methods A prospective cohort study (2022-2025) enrolled 1,495 military and civilian personnel across five academic centers, stratified by experience (novice, intermediate, expert). Skills, including cricothyroidotomy, whole blood transfusion, and ultrasound-guided vascular access, were assessed using validated checklists in Role 2-congruent simulations. Statistical analysis compared checklist performance against participant experience with a priori checklist scores estimated at 40% (novices) and 90% (experts). Results Competency thresholds were established, ranging from 77% (mechanical ventilation) to 100% (handoff). Experts achieved 85%-98% proficiency across most skills, with novices at 34%-97%. A ceiling effect was observed for less complex skills consistent with the power law of practice. Conclusion The Combat Medical Skills Sustainment Consortium validated standardized assessment tools, with potential to address readiness gaps through military-civilian synergy. Findings support consortium-guided curriculum development and highlight the need for longitudinal skill decay studies. Impact This study sets a benchmark for trauma care skills assessment, facilitating rapid adoption across military and civilian settings.