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.