Utilizing gaze patterns and EKG measurements to analyze responses to a “dirty bomb” decision aid in disadvantaged people with limited literacy: How can we make communication materials better?

Background:  Eye tracking and EKG measurements are commonly used evaluation methods in marketing, but have not been used in public health. The purpose of this study was to assess the effect of a decision aid on intended behaviors in a “dirty bomb” in a limited-literacy population in a pilot RCT.  Methods:  Limited-literacy adults were randomized to receive either a CDC “factsheet” ( n=22) or low-literacy decision aid (n=28). Subjects were shown the materials on a computer screen as their gaze pattern and heart rate were measured.  Gaze patterns and EKG readings of participants on content-similar slides were compared and a rating system was used to determine ability to follow text.  Results:  Gaze pattern analysis revealed differing abilities to read densely written material.  Intervention participants took more time to read slide details written at their reading level compared to control participants whose gaze patterns indicated a large amount of unread text, indicating a difference in the ability to understand material and receive key preparedness messages.  EKG data showed that both groups’ heart rates remained relatively constant, however they were slightly slower in the intervention group, suggesting they felt more relaxed and comfortable while processing material they were able to read.  Conclusion: Using these novel methods has potential benefits for analyzing and understanding complex responses to educational material in limited literacy populations, who are vulnerable to negative health events and in the case of a “dirty bomb”, may not be able to understand how to respond based on currently available information.