RESUMO
BACKGROUND: This study investigated the effects of three different risk displays used in a cardiovascular risk calculator on patients' motivation for shared decision-making (SDM). We compared a newly developed time-to-event (TTE) display with two established absolute risk displays (i.e. emoticons and bar charts). The accessibility, that is, how understandable, helpful, and trustworthy patients found each display, was also investigated. METHODS: We analysed a sample of 353 patients recruited in general practices. After giving consent, patients were introduced to one of three fictional vignettes with low, medium or high cardiovascular risk. All three risk displays were shown in a randomized order. Patients were asked to rate each display with regard to motivation for SDM and accessibility. Two-factorial repeated measures analyses of variance were conducted to compare the displays and investigate possible interactions with age. RESULTS: Regarding motivation for SDM, the TTE elicited the highest motivation, followed by the emoticons and bar chart (p < .001). The displays had no differential influence on the age groups (p = .445). While the TTE was generally rated more accessible than the emoticons and bar chart (p < .001), the emoticons were only superior to the bar chart in the younger subsample. However, this was only to a small effect (interaction between display and age, p < .01, η 2 = 0.018). CONCLUSIONS: Using fictional case vignettes, the novel TTE display was superior regarding motivation for SDM and accessibility when compared to established displays using emoticons and a bar chart. If future research can replicate these results in real-life consultations, the TTE display will be a valuable addition to current risk calculators and decision aids by improving patients' participation.