The effects of communicating uncertainty in quantitative health risk estimates

Objective: To examine the effects of communicating uncertainty in quantitative health risk estimates on participants' understanding, risk perception and perceived credibility of risk information source. Methods: 120 first year psychology students were given a hypothetical health-care scenario, with source of risk information (clinician, pharmaceutical company) varied between subjects and uncertainty (point, small range and large range risk estimate format) varied within subjects. Results: The communication of uncertainty in the form of both a small and large range resulted in a reduction in accurate understanding and increased perceptions of risk when a large range was communicated compared to a point estimate. It also reduced perceptions of credibility of the information source, though for the clinician this was only the case when a large range was presented. Conclusions: The findings suggest that even for highly educated adults, communicating uncertainty as a range risk estimate has the potential to negatively affect understanding, increase risk perceptions and decrease perceived credibility. Practice Implications: Communicating uncertainty in risk using a numeric range should be carefully considered by health-care providers. More research is needed to develop alternative strategies to effectively communicate the uncertainty in health risks to consumers. (C) 2012 Elsevier Ireland Ltd. All rights reserved.