Proof-of-concept validation of the MCIPHER mnemonic framework for three-dimensional tabletop mass casualty incident simulation: a quasi-experimental study

Abstract Background Cognitive aids can reduce extraneous cognitive load during mass casualty incident (MCI) management, yet no validated mnemonic framework sequences across all operational phases, from command activation through scene closure, as a single cognitive scaffold. MCIPHER is a five-phase mnemonic (C.O.M.M.A.N.D., S.O.R.T., C.A.R.E., M.O.V.E., C.L.E.A.R.) designed to support novice providers during MCI simulation. This proof-of-concept study evaluated MCIPHER’s effect on team performance, individual confidence, knowledge, and attitudes in a standardised three-dimensional (3D) tabletop MCI exercise. Methods A quasi-experimental, two-group design was conducted at a university simulation centre. Twenty-five PGY-1 residents were allocated to Group A (control, n = 12) or Group B (MCIPHER, n = 13), each forming one team. Both groups completed a pre-course MCI curriculum; Group B additionally received the MCIPHER framework as a cognitive aid. Teams independently managed a standardised 25-casualty tabletop scenario scored on 20 critical actions. Primary team-level outcomes (Team Performance Score [TPS], Operational Timeliness Index [OTI], Triage Accuracy Score [TAS]) were analysed descriptively with Bayesian Beta-Binomial estimation. Secondary individual-level outcomes (confidence, knowledge, attitudes) were analysed with non-parametric tests and Holm-Bonferroni correction. Results Group B demonstrated higher OTI (55.0% vs 30.0%; Bayesian P(B > A) = 0.942), TAS (96.0% vs 80.0%; P(B > A) = 0.951), and TPS (72.5% vs 65.0%; P(B > A) = 0.689). Performance advantages were phase-specific: Group B outperformed on executive phases (Command + 25.0 pp; Closure + 75.0 pp) but scored lower on the procedural Triage phase (− 37.5 pp). Group B attempted 19 of 20 critical actions versus 15 for Group A. A triage accuracy-process dissociation was observed: Group B achieved higher accuracy (96% vs 80%) despite lower triage process scores (62.5% vs 100%). Both groups showed significant within-group confidence gains (Group A: Δ = +1.44, p < .001; Group B: Δ = +0.74, p = .013), converging to equivalent post-training levels (p = .891). MCIPHER was rated favourably (composite 4.27/5). Conclusions MCIPHER shows promising effects on operational timeliness and triage accuracy, with gains concentrated in executive decision-making phases consistent with Cognitive Load Theory. The phase-specificity effect and accuracy-process dissociation are novel findings warranting replication. A multi-site randomised trial with multiple teams per condition is needed to confirm these results. Trial registration ClinicalTrials.gov, NCT07838441. Registered on 24/09/2026. Retrospectively registered.