Alternative Sensory Presentation Formats in Asymptomatic Carotid Stenosis
Alternative Sensory Presentation Formats in Asymptomatic Carotid Stenosis
Background: In a previous study, information verbally presented as relative risk (e.g. "50%
 less likely") or qualitative risk (e.g. "significantly less likely") resulted in many more
 people (66%) choosing a surgical procedure for narrowing or artery in the neck than people
 presented with absolute risk (e.g. "11% versus 5% over 5 years"), annualized risk (e.g. "2%
 versus 1% per year for 5 years") and event-free survival (e.g. "95% versus 89% over 5 years")
 (33%).

 Objectives: The purpose of this study is to determine whether the same observations are true
 for information that is presented visually as a bar graph. In addition, the investigators
 also seek to determine whether subjects feel that they understand the information better when
 presented visually as compared with verbally.

 Methods: 450 subjects will be approached in the neurology clinic as they are waiting for
 their office visit. If the subject agrees to participate in this 10 minute study, they will
 be taken to a quiet room where they will watch a 1 minute video on a laptop. The video will
 feature an acting physician. The presenter will be the same for all experiment groups. The
 presenter will describe a hypothetical medical situation in which a narrowing of one of the
 carotid (neck) arteries is present. The presenter will then describe the risk of a stroke
 related to that condition if the subject chooses medical therapy versus medical and surgical
 therapy. The presentation of risk will vary and may be presented in one of 3 different ways
 including a qualitative description, an absolute risk reduction over a fixed time period, and
 a relative risk reduction. These three risk groups will be presented either verbally or
 visually through bar graphs. In the visual subject groups, the presenter will be holding up a
 graph and remain silent while the graph is shown. The amount of time allotted for the graph
 on the video will be equal to the amount of time it takes the presenter to say the
 information in the auditory subject groups. Given that there will be 2 sensory modalities
 (verbal of visual) and 3 different presentation formats, there will be a total of 6 different
 videos. After the video is complete, the subject will be asked to complete a 1 page survey
 which will ask about the patient's age, gender, educational level, reason for the medical
 visit, and final decision about choice of treatment. The subjects will also answer how well
 they understood the data by making a mark on a 10 cm horizontal line.
Background: A previous randomized study found that verbal presentation of benefit of surgery
 in asymptomatic carotid stenosis expressed as qualitative or relative risk resulted in a
 higher proportion (66% versus 33%) of subjects choosing surgery as compared to subjects
 presented absolute risk, yearly risk, or event-free survival. Other variables that increased
 the choice of surgery were male gender, younger age, and higher level of education.
 Nevertheless, presentation format was the strongest predictor of treatment choice.

 Objective/Hypothesis: To determine whether presentation format affects visual representation
 of information. The investigators hypothesis is that visual representation of both positive
 and negative outcomes in a single bar graph will result in less subjects favoring surgery as
 compared to those only shown relative information in a bar graph. The investigators also
 hypothesize that subjects shown visual information will express a greater understanding of
 information presented to them as compared to those given verbal information.

 Specific Aims: 1) To determine whether presentation format affects visual representation of
 information. 2) To determine whether subjects given visual representations of information
 express a greater understanding of the information as compared with subjects given verbal
 representations of information.

 Study Design: 450 subjects will be approached in the neurology clinic as they are waiting for
 their office visit. Subjects without carotid stenosis will be approached randomly by the
 principal investigator or one of the co-investigators. They will be asked to participate in
 the study after completing their office visit with their physician. In the event that the
 patient is expecting longer than a 30 minute delay to see their physician, they will be asked
 to participate in the study prior to the office visit. If the subject agrees to participate
 in this 10 minute study, they will be taken to a quiet room where they will watch a 1 minute
 video on a laptop. The video will feature an acting physician. The presenter will be the same
 for all experiment groups. The presenter will describe a hypothetical medical situation in
 which a narrowing of one of the carotid arteries is present. The presenter will then describe
 the risk of a stroke related to that condition if the subject chooses medical therapy versus
 medical and surgical therapy. The presentation of risk will vary and may be presented in one
 of 3 different ways including a qualitative description, an absolute risk reduction over a
 fixed time period, and a relative risk reduction. These three risk groups will be presented
 either verbally or visually through bar graphs. In the visual subject groups, the presenter
 will be holding up a graph and remain silent while the graph is shown. The amount of time
 allotted for the graph on the video will be equal to the amount of time it takes the
 presenter to say the information in the auditory subject groups. Given that there will be 2
 sensory modalities (verbal of visual) and 3 different presentation formats, there will be a
 total of 6 different videos. Randomization will be performed by selecting a video number from
 an opaque envelope. The subject will be allowed to watch the video up to 3 times, if
 requested. After the video is complete, the subject will be asked to complete a 1 page survey
 which will ask about the patient's age, gender, educational level, reason for the medical
 visit, and final decision about choice of treatment. The subjects will also answer how well
 they understood the data by making a mark on a 10 cm horizontal line. A mark further to the
 right signifies better understanding than a mark placed to the left. Data will be entered
 into a spreadsheet which will then be used to analyze aggregate data.
Inclusion Criteria:

 -  Age 18 or greater

 Exclusion Criteria:

 -  No history or carotid stenosis

 -  No history of dementia