Assessing the Impact of Visualizations of Quantitative and Qualitative Risk Information on the Comprehension of Hypothetical Risk-Based Breast Cancer Screening Results

This study aimed to assess whether, in the context of communicating risk-based breast cancer screening results, visualizations of risk information consisting of an icon array depicting quantified breast cancer risk and simplified drawings for "qualitative" risk information (e.g. risk factors, screening frequency) offer added value compared to a textual format presenting numerical information. An online experiment was conducted with a 3 (information format: text with numbers - text with risk visualizations - interactive) ×4 (breast cancer risk category: slightly decreased, average, slightly increased, increased) between-subjects design. We recruited <i>n</i> = 1,047 women aged 40-74 years from the general Dutch population, including 413 (39.4%) with lower education and 269 (25.7%) with a family history of breast cancer. Participants viewed hypothetical screening results. Primary outcomes were verbatim and gist comprehension of numerical probability information and verbatim comprehension of qualitative risk information. Secondary outcomes (e.g. affective reactions, perceived likelihood) and health literacy, numeracy, and graph literacy were also assessed. Results showed no significant differences in comprehension between "text with risk visualizations" and "text with numbers" formats. Verbatim comprehension of numerical probability and qualitative risk information was worse in the "interactive" format compared to "text with numbers" format. Those assigned to a non-average risk category exhibited lower verbatim and gist comprehension. Overall, the visualizations tested in this study did not enhance comprehension of risk-based breast cancer screening results compared to a text format with numerical information. Understanding risk-based screening results may be challenging regardless of format, particularly for people assigned to a non-average risk category.