Appendix Table 1.

Risk Concepts, Task Descriptions and Multimedia Strategies for Displaying Risk Estimates.

Risk Concept	Task Description	Multimedia Strategies
1. Relevant Group	Relevant group: Understand the nature and size of relevant population Group identification: Understand that pictograph “represents individuals like you” Personal risk identification: User should be able to identify that he/she is in the at-risk group	Relevant group: Icons are highlighted/colored/halo’d when narrator mentions the relevant group. Group identification: Uses U.S. map to indicate the entire population Is the relevant group Group identification/Personal risk: Graph shows slope indicating colorectal cancer risk increases sharply after age 50, stops increasing after age 75
2. Denominator	Denominator is a sample representing total population.	We use bulleted text to show both the numerator and denominator We consistently use 100 as the denominator for incidence, mortality, and incremental benefit We present the sample denominator from the population: Sample population is shown from U.S. map and then immediately the 10×10 icon array Narration explicitly states taking a random sample from the U.S.
3. Numerator	Affected and unaffected group: User should understand what the numerator represents (how many affected and how many unaffected) in relationship to the denominator Identify how the numerator is drawn from the denominator Uncertainty around will be affected and who will not be affected	Affected and unaffected group: Both positive and negative framing is used throughout (i.e., narration and bulleted text) Affected and unaffected group: Icons representing the numerator are highlighted and haloed while the unaffected group remains static – no highlights Numerator drawn from the denominator: Narration says, “Of the 100 people” Uncertainty: We use narration such as: “we do not know today who will get colon cancer” 3 of 6 people with colon cancer will die from it. We do not know today who these 3 will be” Uncertainty: Affected group Icons are chosen at random to indicate the affected to indicate the randomness of who will get colorectal cancer or who will die from colorectal cancer. After they are chosen/highlighted, the affected group is lined up in the first row for easier counting. When the narration states “We do not know today who will get colon cancer” the affected icons are chosen again at random
4. Time Frame	Time period for event to occur: User should understand time frame for risk estimate as well as the change per time frame (the change in rate of change) Personalize risk over time: Interpret the given time from in regards to the user (i.e. their age) Change in the rate of change: Understand the concept of a change in the rate of change (e.g., as you age, the risk goes up even faster)	Time period: Narration uses “over their lifetime” to indicate the time period for the event to occur Change in the rate of change: Narration: “People are more likely to get colon cancer as they get older” Graph: Slope indicating colorectal cancer risk increases sharply after age 50, stops increasing after age 75
5. Increment-al Benefit	Incremental benefits/risk: Understand the benefit/risk associated with 2 or more strategies (e.g., no screening graphic and screening graphic, depicting mortality benefit).	Changes in the icon array for benefit of screening (with screening, without, deaths with and without) 1.5 of the 3 icons change from red to white to indicate that they are saved from dying by being screened Text on the bottom of the screen: 1–2 out of 100 people will die from colon cancer 1–2 out of 100 people will be saved from dying from colon cancer Narration emphasizes how many people are saved from colon cancer by screening
6. Rare Events	Magnitude of rare events: Understand how common a rare event is within the content of the at-risk population Fractions of a person: How to handle an event that occurs as a fraction of a person, such as 1.5 people will…..?	Fractions: Narration uses “number of deaths due to colon cancer will be cut in half” 1.5 of the 3 icons change from red to white to indicate that they are saved from dying by being screened
7. Uncertainty with Risk Estimate*	Uncertainty around point estimates: Understand that probability is an estimate involving a degree of imprecision Issues for research: Understand what the uncertainty means in terms of preferences and decisions.

^*Note: Understand uncertainty with risk estimate (7) was not included.