Effect of risk communication formats on risk perception depending on numeracy

To examine the influence of numeracy on interpreting various risk communication formats.

. A random sample of women (N = 266) completed a questionnaire assessing numeracy and risk perception of prenatal test results and results of colon cancer screening tests. The authors examined the relationships between risk level (high v. low) and format of risk presentation (ratio, pictogram, or Paling Perspective Scale) and whether these relationships differed based on the numeracy skills of the participant.

The authors identified a significant (P<0.001) 3-way interaction between format, risk level, and numeracy: high-numerate participants in the low-risk group perceived the test results as less risky compared with participants in the high-risk group (P < 0.001) with the Paling Perspective Scale but not with the other formats. For low-numerate participants, they did not observe differences between low- and high-risk scenarios for any of the 3 formats. The results were similar for the Down syndrome and colon cancer scenarios. Overall, the pictogram resulted in significantly lower risk ratings compared with the Paling Perspective Scale and the ratio with numerator 1 (P < 0.001).

Different communication formats may produce different risk perceptions, but the effect is qualified by patients' numeracy skills.