Figure 2. Using a stepped-wedge design, we will conduct this study over six 3-month long waves at eight high-volume trauma centres. During the first wave, all patients will receive usual care. With each subsequent wave, two randomly selected sites will enter the implementation phase. Data collection will cease during implementation and the study implementation team will train clinicians to use the Best Case/Worst Case-ICU tool. Following the wave for implementation training, patients will receive care from a trauma team that routinely uses the Best Case/Worst Case-ICU tool. ICU, intensive care unit.