Abstract 277: Conveying Risks and Benefits of rt-PA: the Eyes Have It

Abstract

Background: During the early phase of ischemic stroke (IS), thrombolytic (recombinant tissue plasminogen activator; rt-PA) therapy has been shown to effectively reverse symptoms and improve outcomes. However, serious bleeding can occur, which has discouraged both patients and physicians from using rt-PA. The purpose of the overall study is to create a decision-making tool that accurately depicts the risk and benefits of rt-PA in a graphical format that effectively engages physicians, patients and their families. Methods: To better understand the most effective method for presenting the probabilities of outcomes we used eye-tracking technology (Applied Science Laboratories D-6 optics) to assess the manner in which participants studied graphs of varying formats. We recorded which components of the graphs that participants looked at, and how long they looked at these graph components. The graphs were developed from a series of qualitative studies and showed 3 representations rt-PA benefits drawn from the NINDS data: bar; stacked bar; and iconic (person outline figures) graphs. Each presented probabilities for outcomes ranging from little/no disability to severe disability/death and risk of bleeding with or without rt-PA use. Stroke survivors or family members were randomly presented with one of the graphs and asked to imagine they were consulting with a physician about using rt-PA for a family member who had just had a stroke. Comprehension was tested with questions assessing knowledge of the risk and outcome percentages presented in the graphs. Results: Participants (n=12) spent a longer time studying the iconic and bar graphs (mean = 64 seconds and 63 seconds, respectively) than the stacked bar graph (mean = 46 seconds). Study time in different graph regions varied by graph type. Participants spent 16%, 7.5 %, and 1.4 % of their study time looking at the key risk information in the stacked bar, bar, and iconic graphs, respectively. In addition, 4 out of 5 subjects who incorrectly identified the risk of bleeding on the comprehension test had studied the iconic graph. When shown all three formats, participants indicated the iconic graph to be confusing and the stacked bar to be most informative. Conclusions: Our preliminary data suggest that stacked bar graphs facilitate better understanding of the risks and benefits of rt-PA in acute IS. Presenting data in this format could better engage patients and families in making treatment decisions in the setting of IS.