The effect of numerical statements of risk on trust and comfort with hypothetical physician risk communication

Objective. To contribute to the debate about whether numeric statements of risk ought to be included in risk communications. Design. Subjects (n = 115) completed a questionnaire involving a physician risk communication and 4 scenarios, each of which described a patient with symptoms and signs potentially suggestive of cancer. Each scenario was presented in 3 risk communication versions (a verbal version and 2 numeric versions) in a within-subject 4 x 3 design. Subjects rated their trust in and comfort with the information and their belief that the physician distorted their risk level. Results. Subjects were significantly more trusting of (t = 4.0, P < 0.001) and comfortable with (t = 3.4, P = 0,001) the risk information, less likely to believe that the physician minimized the risk in the numeric versions than verbal versions (t = 4.3, P < 0.0001), and just as likely to believe that the physician exaggerated the risk in the 2 versions (P = 0.588). Conclusions. Including a numeric statement of risk in a risk communication can increase trust and belief in and comfort with the risk information.