Association between mass casualty in-situ simulation format with ongoing operational and patient care metrics in an adult emergency department: a retrospective cohort study

Background In situ simulation (ISS) has seen broad use in academic emergency medicine (EM). Studies with limited clinical data suggest a dual paradigm model to assess the efficacy of these educational activities based on their impact on both ongoing and future quality of care. We conducted a retrospective cohort study to assess the impact of government-mandated mass casualty incident (MCI) ISS drills on ongoing department operations and quality clinical care. Methods We conducted a retrospective study of patients presenting to an adult tertiary academic emergency department during scheduled and unscheduled ISS MCI drills. We assessed the impact of ISS on operational and triage metrics by comparing scheduled and unscheduled drills. Results Being treated during an ongoing MCI ISS, in both the scheduled and unscheduled simulation formats, was associated with a higher average door to triage times (20.6 min in the MCI ISS cohort vs 15.8 min in the control cohort; p<0.005) and lower Canadian Triage and Acuity Scale (CTAS) scores (CTAS 1 and 2: 0.8% and 14.5% in the MCI ISS cohort vs 1.6% and 17.1% in the control cohort, p<0.025). Secondary analysis, evaluating differences between case and control cohorts in distinct scheduled and unscheduled ISS subgroups, showed that unscheduled but not scheduled ISS were associated with higher average door to triage times (29.0 min in the unscheduled MCI ISS case cohort vs 21.2 min in the unscheduled MCI ISS control cohort; p<0.001) and lower CTAS acuity scores (CTAS 1 and 2: 0.0% and 17.9% in the unscheduled MCI ISS cohort vs 2.8% and 27.9% in the unscheduled MCI ISS control cohort; p<0.001). Conclusion In this study, there was a significant association between increased door to triage time and lower acuity triage score designation for patients treated during an ongoing MCI ISS education drill. Secondary analysis demonstrated that these findings were only observed during unscheduled simulations, suggesting that the effects may be modifiable.