This project aims to explore the strategies that patients with lower health literacy/math skills use in processing and applying numerical outcome information in their own choice process. Additionally a product-service system will be develeped, that initiates a new mode of communication tailored to those strategies of patients. Patients with lower health literacy/math skills themselves actively participate in the project. All of this is being explored in oncology care for patients with gastrointestinal cancer.
Within cancer care, more and more outcome information is available, including information from clinical prediction models. Outcome information is about both clinical outcomes and quality of life, the latter usually reported through patient-reported outcome measures (PROMS). This is also the case for gastrointestinal cancer, where the Dutch SOURCE prediction model predicts personalized patient outcomes. The use of such outcome information offers benefits for clinical decision-making of doctors, but also for Shared Decision Making (SDM) between doctors and patients. Therefore, a SOURCE tool has been developed for use in the consulting room. Numbers are displayed with visual representations. Doctors received training to use the tool.
An initial analysis of consultations in the consulting room (N=15) showed that patients understood displayed SOURCE numbers reasonably well. For example, a 60% survival rate means that 60 out of 100 patients will be alive in X years. This is also called "verbatim understanding," i.e. literal understanding. Often this understanding arises immediately, but it also quickly subsides. It was less clear whether patients also developed "core comprehension," or knowledge of the underlying core meaning. This knowledge tends to stay in memory longer and is essential in making choices. Analyses further showed that doctors' explanations were quite time-consuming. This left less time to discuss how the patient can weigh the numbers, and what the patient himself considers more and less important in this. This SOURCE case is consistent with the literature: when more information becomes available, doctors put a lot of effort into explaining numbers well. This is positive in itself, but not if it comes at the expense of clarifying patient preferences. This poses particular problems for patients with lower health literacy and/or numeracy skills, who already have more difficulty using numbers.
The central problem is that patients with lower health literacy/math skills still have great difficulty processing numerical outcome information in cancer care and applying it in their own choice process. It has also proven difficult to examine the voices of those patients because they are less likely to participate in scientific studies.
