Design and usability of the CUMACA-M mobile app for long-term breast cancer survivors

Long-term breast cancer survivors often continue to experience physical and psychological sequelae that affect their quality of life and self-efficacy. Mobile health interventions offer a promising approach to providing personalized and continuous support; however, few have been specifically developed for the long-term survivorship stage. This study describes the design, development, and usability assessment of CUMACA-M, a mobile application aimed at improving quality of life and self-efficacy among long-term breast cancer survivors by supporting the management of persistent sequelae. The research followed the Medical Research Council framework for complex interventions. In the first phase, CUMACA-M was created using a user-centered design approach. Its content was validated by a multidisciplinary panel of experts, whose feedback was complemented by insights from a focus group of long-term breast cancer survivors. In the second phase, usability was evaluated through a mixed convergent design combining the System Usability Scale (SUS), the think-aloud method, and semistructured interviews. Sixteen women recruited from a patient association participated in this stage. The application achieved an average SUS score of 84.84, indicating excellent usability. Participants emphasized the app’s ease of use, personalized content, and intuitive interface, while also suggesting improvements such as clearer tutorials and enhanced visualization. Qualitative findings confirmed the app’s positive influence on organization and motivation for self-care. Overall, CUMACA-M represents a valuable advancement in the digital support of long-term breast cancer survivorship. Its user-centered development and validation by both experts and end users reinforce its relevance and acceptability, while also guiding future enhancements to broaden its functionality and accessibility.