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 presented