Measured task load in directed observers versus active participants undergoing high-fidelity simulation education in a critical care setting.

Objectives: The use of directed observers in high-fidelity simulation education is increasingly common. While evidence suggests similar educational outcomes for directed observers compared to active participants in technical skills, it remains uncertain if this benefit also exists for senior clinicians, especially in mental workload. We sought to compare the workload between active participants and directed observers using an objective measure. Methods: We performed a prospective, repeated-measures observational study during the New South Wales Ambulance Aeromedical Operations induction training from 2019 to 2020. Participants included senior critical care doctors, paramedics, and nurses undergoing high-fidelity simulation of prehospital and interhospital aeromedical missions. Task load was measured using the National Aeronautics and Space Administration task load index (NASA-TLX) administered following each simulation debrief. Prehospital and interhospital simulations were compared separately by building a multilevel model for complete case and all study data. Post hoc comparisons of NASA-TLX score for each group were performed using estimated marginal means (EMMs). Results: We enrolled 70 participants, comprising 49 physicians (70%), 19 paramedics (27%), and two flight nurses (3%). From the complete case analysis, statistically significant differences were observed for total NASA-TLX scores between active participants and directed observers in both prehospital (participant EMM 78, observer EMM 65, estimated difference -13, 95% confidence interval [CI] -20 to -7) and interhospital simulations (participant EMM 69, observer EMM 59, estimated difference -10, 95% CI -16 to -3). When all available data were included, the pattern of results did not change. Conclusions: In our sample of senior clinicians, the task load experienced by both active participants and directed observers in high-fidelity simulation education was high for both prehospital and interhospital simulation exercises. The statistically significant differences we report are unlikely to be practically significant. Our results support the use of directed observers when resource limitations do not allow all course attendees to participate in every simulation.