WORK-ICU: Understanding Cognitive Load as a Measure of Workload for ICU Physicians

Introduction: Accurate measurement of intensivist workload can improve patient care and physician well-being. Current workload measures (e.g. patient-to-physician ratios) likely miss important aspects of workload. We ultimately aim to assess whether cognitive load (CL) is associated with physician and ICU characteristics as a first step to using CL as a measure of ICU workload.


Methods: We conducted a cross-sectional online survey of intensivists across the US and Canada assessing cognitive load (CL) and its association with physician and ICU characteristics. CL was measured using the NASA Task Load Index (TLX), a validated tool for CL. Participants rated a single day of ICU work across 6 subscales from 0 to 100 (total score 0 to 600, higher scores=higher CL). This study was funded by the SCCM Discovery Research Grant.


Results: We had 685 intensivists participate in the study from 48 states and 6 Canadian provinces. The median age was 43 years (IQR 37, 52), with 46% participants identifying as women. Sixty-two percent of intensivists worked in academic centers and 35% in a community hospital. Most worked in combined medical/surgical ICUs (41%) or medical ICUs (28%). The median ICU census was 14 (IQR 10, 16) and on average, 50% of patients required invasive mechanical ventilation. The median ICU mortality rate was 15% (IQR 5, 25). Most intensivists worked in ICUs with fellows (62%) and/or advanced practice providers (71%). The median TLX score was 335 (IQR 275, 390). Mental demand had the highest median subscale score of 75 (IQR 67, 85), and performance demand had the lowest median score of 25 (IQR 11, 70). Sixty-eight percent of the intensivists reported experiencing burnout symptoms (assessed by the Maslach Burnout Inventory) a few times a month or more often.


Conclusions: Our study enrolled a diverse group of intensivists across North America. We show a high median CL similar to previously reported TLX scores among critical care physicians. This preliminary data is the initial step towards our aim to assess the relationship of CL with individual physician/ICU characteristics in a multivariable linear mixed effects model.