Developing a subjective instrument for laparoscopic surgical workload in a high fidelity simulator using the NASA-TLX and SURG-TLX

The Surgery Task Load Index (SURG-TLX) and National Aeronautics and Space Administration Task Load Index (NASA-TLX) are subjective workload assessment instruments. These instruments have three coinciding workload dimensions, but each has three unique dimensions. Each dimension is explained by a unique descriptor. It was hypothesized that the SURG-TLX and NASA-TLX workload ratings would differ when assessing the same surgical methods and tasks. Accordingly, the aim of this study was to assess the SURG- and NASA-TLX dimensions toward the creation of a novel workload instrument to better predict simulated laparoscopic surgical workload. Twenty-five (25) participants were selected at a large, midwestern teaching hospital to conduct two simulated surgical tasks using four different laparoscopic methods. Each participant completed a total of eight trials and after each trial workload was assessed using both the NASA-TLX and SURG-TLX. The overall NASA-TLX dimensions were rated significantly higher (greater workload) compared to the overall SURG-TLX dimensions (F = 12.04, p = 0.001). Principle component analysis of workload dimensions suggests that a new surgical subjective workload measurement instrument should include the dimensions of Mental Demand, Physical Demand, Temporal Demand, Performance, Frustration and Situational Stress. However, validation of this novel tool is needed.