Presenting decision-relevant numerical information about survival rates and side-effects to patients with varying levels of Health Literacy: case example of adjuvant therapy in breast cancer (Oral presentation)

Introduction Decision-relevant numerical information about treatment options presented in Patient Decision Aids/a consultation, is important for Shared Decision Making (SDM). In two experiments risk communication formats to present probabilistic information to patients with varying levels of Health Literacy (HL), numeracy, and Graph Literacy (GL) were investigated using adjuvant therapy for breast cancer as a case example. Methods Two between-subjects experiments were conducted with hypothetical scenarios, among women aged 50-70 years. The first experiment (n = 219) investigated the effect of survival rate format (i.e., textual, bar graph, and icon array) on gist and verbatim comprehension. The second experiment (n = 282) investigated the effect of side-effect presentation format (i.e., text, numbers, visualization, description of the side-effects with numbers or a visualization) on gist comprehension and feeling informed. Results No significant differences in the primary outcomes were found for the different survival rate presentation formats. Although gist and verbatim comprehension were influenced by HL, numeracy, and GL, no interaction effects with format were found. The effect of the presentation format of side-effects on participants’ comprehension and feeling informed are currently being analyzed. Discussion Contrary to previous literature, the format in which survival rates were presented did not affect any of the outcomes assessed, irrespective of the patients’ information processing skills. The number of treatment options, in this case, three, and the presented small difference in survival rates between these options might have influenced these results. Conclusion The survival rate presentation format did not affect patients’ responses to the numerical information presente