User-Centered Design And Usability Evaluation Of A Cancer Prevention Web Application: An Iterative Approach In Germany

ObjectivesLimited public awareness of cancer risk factors necessitates effective dissemination of cancer prevention information. Digital technologies offer an opportunity to address this gap, yet there is scant information on tools for communicating cancer prevention evidence. This article describes the user-centered design, development and usability evaluation of a web application for personalized cancer prevention tailored to the German population. Materials and MethodsPrototypes of the web-app were developed through early and continuous formative evaluations. These prototypes integrated validated cancer risk prediction models and recommendations using an evidence-based risk communication approach. In a graphical user interface (GUI) test usability was assessed using the system usability scale (SUS), deriving scores for overall usability, usefulness, and learnability. Qualitative data on user experience (UX) and user interface (UI) issues were also collected through think-aloud protocols, interviews, and questionnaires. FindingsThe GUI test showed a SUS score of 69.7/100 and a usefulness score of 75.8, indicating acceptable usability, while the learnability score was 48.4. Eight categories of UX/UI problems were identified, including one severe and three moderate issues related to data input, user guidance and risk visualization. Qualitative feedback highlighted strengths in navigation, information presentation, and interactive features such as the risk simulation tool. DiscussionThe iterative development and early user testing yielded valuable feedback, identifying key usability concerns during prototyping. The usability score was within an acceptable range, and the usefulness score was above average. However, the lower learnability score indicated potential challenges in user understanding and satisfaction. Identified usability issues highlight areas for improvement while positive feedback supports the design choices, particularly the use of visual aids, numerical data, and personalized feedback to improve risk comprehension and motivate behavior change. ConclusionThe NCPC cancer prevention web application represents a significant step towards effective digital health promotion in Germany. Addressing identified usability concerns through continued iterative refinement and user involvement is crucial for enhancing the tools effectiveness. The integration of evidence-based risk communication strategies shows promise in improving risk comprehension and motivating behavior change among users.