Objectives
This systematic review examines how design methodologies support Shared Decision Making (SDM), identifies the most suitable for future use, explores types of methodologies used, challenges faced, and the impact on patients, clinicians, and care pathways.

Methods
Studies were searched on Medline, Web of Science, Scopus and grey literature (Google Scholar, CORDIS) up to July 2024, following PRISMA guidelines.

Results
were analysed to identify patient involvement, design strategies, SDM solutions, and their impact on care paths, professionals, and patients.

Results
Out of 2499 studies and 39 grey literature projects identified, 22 studies (reported in 35 publications) were selected, primarily from the USA and Europe (2015 onward). User-Centered Design predominated, involving health professionals more than patients. IPDAS standards were common. Evaluations showed improved patient experience and SDM role, with a potential increase in healthcare professionals' workload.

Conclusion
Although design methodologies are used in SDM implementation, improvement is needed. Service Design can enhance implementation by analysing the entire SDM process, while co-creative approaches develop patient-focused solutions that integrate smoothly into health professionals' workflows.

Practical implications
Introducing SDM in healthcare is complex, but design methodologies can help by analysing stakeholder needs, providing a broader care path view, and facilitating SDM implementation.@en

Background:
Patients with cancer often have to make complex decisions about treatment, with the options varying in risk profiles and effects on survival and quality of life. Moreover, inefficient care paths make it hard for patients to participate in shared decision-making. Data-driven decision-support tools have the potential to empower patients, support personalized care, improve health outcomes and promote health equity. However, decision-support tools currently seldom consider quality of life or individual preferences, and their use in clinical practice remains limited, partly because they are not well integrated in patients’ care paths.

Aim and objectives:
The central aim of the 4D PICTURE project is to redesign patients’ care paths and develop and integrate evidence-based decision-support tools to improve decision-making processes in cancer care delivery. This article presents an overview of this international, interdisciplinary project.

Design, methods and analysis:
In co-creation with patients and other stakeholders, we will develop data-driven decision-support tools for patients with breast cancer, prostate cancer and melanoma. We will support treatment decisions by using large, high-quality datasets with state-of-the-art prognostic algorithms. We will further develop a conversation tool, the Metaphor Menu, using text mining combined with citizen science techniques and linguistics, incorporating large datasets of patient experiences, values and preferences. We will further develop a promising methodology, MetroMapping, to redesign care paths. We will evaluate MetroMapping and these integrated decision-support tools, and ensure their sustainability using the Nonadoption, Abandonment, Scale-Up, Spread, and Sustainability (NASSS) framework. We will explore the generalizability of MetroMapping and the decision-support tools for other types of cancer and across other EU member states.

Ethics:
Through an embedded ethics approach, we will address social and ethical issues.

Discussion:
Improved care paths integrating comprehensive decision-support tools have the potential to empower patients, their significant others and healthcare providers in decision-making and improve outcomes. This project will strengthen health care at the system level by improving its resilience and efficiency.@en