Despite improved treatment methods, 450,000 Norwegians live with chronic cardiovascular conditions, which not only affect their daily lives but also have implications for clinicians, health care systems, and society at large. The Patient-Reported Outcomes in Cardiology (PROCARD) research group focuses on patient-reported and clinical outcome measures to promote patient-centered care and treatment in cardiology. Through embedded collaboration with regional, national, and international hospitals, municipalities, and academic institutions, the consortium has initiated several large projects aimed at developing and researching equitable CR across the cardiovascular disease (CVD) population. Despite these efforts, many people diagnosed with CVDs are unable to reduce known risk factors for CVD. Therefore, PROCARD initiated the eCardiacRehab study embedded in clinical practice. The group has an interdisciplinary approach as the foundation for shared decision-making between patients and clinicians.

Based on a user-centered design [17], the development process (Figure 1) of the digital CR program entailed an iterative 3-staged co-creation process (Figure 2) according to the Medical Research Council (MRC) framework [18]. The project used well-established multidisciplinary CR concepts and class 1A recommendations for secondary prevention of CVD from clinical guidelines [3] as an evidence-based foundation for the co-creation process. The development process was reported in accordance with the GUIDED (Guidance for Reporting Intervention Development Studies in Health Research) checklist (Checklist 1) [19].

The multidisciplinary project team consisted of researchers, clinicians, a software team of technology developers and designers, and user representatives, who helped ensure that content and materials were presented in an understandable manner. The project team was involved in all phases and met on a regular basis: monthly, weekly, and sometimes more often during the development process from January 2021 until the feasibility phase in January 2025.

Health care and research participants were sampled purposively [20] to contribute their competence and experience to the co-creation process, reflecting the multidisciplinary nature of CR (eg, cardiology, nursing, physiotherapy, clinical nutrition, and pharmacology), cardiac and outpatient care (general practitioners [GPs], nurses, and cardiologists), eHealth development, and software and technology.

To be eligible as a user representative, the person had to be aged 18 years or older, have a diagnosis of CVD, and be Norwegian-speaking. A specific goal was to recruit a diverse group of user representatives across age groups and genders through the local branch of the National Association for Heart and Lung Diseases.

The data material was compiled through a 3-phase, iterative process using several data sources (Table 1).

Phase 1 provided insights into end users’ needs through multiple methods: contextual inquiry, stakeholder workshops, and individual interviews, ensuring that the project was well anchored.

Phase 2 included an iterative process consisting of 12 co-creation sessions and content development. Dedicated user representatives (n=8), aged 39 to 73 years (Table 2), participated in 12 co-creation sessions from July 2022 to December 2023. All participants lived in an urban area, and each co-creation session lasted approximately 2 hours, including 9 in-person meetings and 3 digital meetings. The purpose was to elicit ideas on design and content features and further explore users’ requirements for a digital CR program, with each session informing the next. First, a low-fidelity paper prototype, based on evidence-based topics, clinical guidelines, and logistics from local CR programs, was discussed. Throughout the process, the content was continuously shaped, adjusted, and adapted using an iterative approach based on user representatives’ feedback.

All co-creation sessions were facilitated by the second author (KJR) in collaboration with other team members (TMN, NH, TRP, and OKN) and documented in meeting minutes. The first author summarized the material and ensured that it provided essential input into the ongoing development process. The written material was analyzed using qualitative content analysis [28] and sorted into categories representing (1) content, (2) functionality, (3) design, and (4) barriers and facilitators to use (Table 3).

Furthermore, the development of the technology underwent several iterations depending on the topic, with the involvement of the information and communication technology (ICT) team and clinical experts to ensure the use of appropriate language in brief, readily understandable sentences suitable for computer screens. To evaluate the readability of the text, the Gunning Fog Index tool [29] was used. The tool is designed to estimate the years of formal education required to understand a piece of written text on the first reading.

The aim of phase 3 was to test and optimize the user interface and further develop the technical specifications and details of the program.

The study was reviewed and approved by the Regional Ethics Committee (REK 2015/57 and 459136) and registered at ClinicalTrials.gov (NCT06759805). User involvement was guided by the PRO-Ethics framework [34], a European Union Horizon initiative that emphasizes ethical, inclusive, and transparent participation in research and innovation. This framework supported the design of a participatory process that ensured all participants were treated with respect and had equal opportunities to contribute.

The participants were recruited through a regional patient organization, provided written informed consent, and were informed of the right to withdraw at any time. However, none of the participants withdrew from the study. The majority contributed to all co-creation sessions and participated in workshops, with only a few not participating due to an inconvenient schedule. All contributors were granted full anonymity during the process and in reporting of this study. Participants were involved at all levels of consultation and development, and their voices were given decision-making power in the different steps of the co-creation process, as described.

The 12 co-creation sessions contributed to the development of the prototype from low to high fidelity. The target audience representation was adequate, as the participants included both women and men within the target age range who had CVD, and all used a mobile phone and/or computer in daily life. Prototypes of increasing fidelity were developed, with testing of the content, animations, videos, language, navigation, and labels, including appealing features such as the personal health data entry for self-monitoring (Figure 4).

Throughout the co-creation sessions, a range of viewpoints and preferences regarding the use of a digital CR program were revealed. The role of technology in day-to-day life varied in the group. While most users foresaw great benefits from a digital CR solution, some also highlighted uncertainty about its benefits. Comments made by the user group illustrate the link between categories and end-product features representing (1) content, (2) functionality, (3) design, and (4) barriers and facilitators to use (Table 3). At the start of the co-creation sessions, users listed their preferred attributes for the digital program, highlighting the following: a physical consultation at the start of the program, a chat function during the rehabilitation period, counseling on diet, the involvement of next-of-kin, goal-setting, and progression measures. During the co-creation sessions, users had access to high-fidelity prototypes and specific content, such as modules, animations, and videos. An example of feedback was the setup of the modules, where the module on psychosocial health was deemed so important that it was prioritized as the third component in the sequence. Another example was the suggestion to develop a module on female heart health and a resource library to gather trustworthy information. Although the number of participants in the group was small, a saturation effect in terms of the feedback and input from participants was reached.

Building on the feedback and discussions within the project team, a prototype was developed that included a start page with a menu and 9 cardiac-specific interactive learning modules in 5 main components: (1) physical activity and exercise, (2) healthy lifestyle education, (3) psychosocial health, (4) self-monitoring and self-management, and (5) medication adherence. Furthermore, a registration module for health data entry for self-monitoring (medications, weight, blood pressure, blood sugar, activity, diet, sleep, mental health, and nicotine status) was designed (Figure 4). The program also includes real-time guided workout sessions led by physiotherapists, real-time medical yoga sessions, and educational videos in all modules. An asynchronous messaging service and scheduled digital consultations ensure communication with the multidisciplinary CR team throughout the program. Moreover, 2 user stories were developed to illustrate different CR trajectories (Figure 4), including variations in acute care pathways across the program’s modules. These user stories were included in the program to provide patients with relatable scenarios, compensating for the lack of peer interaction typically present in center-based CR. The readability screening revealed a suitable Gunning Fog Index, with optimal readability levels identified as falling within the range of 4 to 13. This indicates that the text is comprehensible to readers with 9 or fewer years of formal education. The overall SUS score was 86.2 (SD 12.2), indicating excellent usability.

In this study, we describe the iterative co-creation process and design of eCardiacRehab, a multimodal digital CR program. To our knowledge, this is one of the few studies that combine thorough stakeholder and user involvement and research their preferences. Moreover, this approach combined stakeholder and user perspectives with evidence-based knowledge to develop a digital home-based CR program that covers all guideline-directed components of CR.

The development process combined evidence-based and user-centered approaches, a recommended but underused approach to the development of eHealth solutions [36]. In this study, we incorporated all guideline-recommended modalities of CR. Although some initiatives, such as CoroPrevention [37] and INTERCEPT [38], have recently taken the multimodal approach forward, prior digital interventions have focused primarily on physical activity or exercise training and have lacked the full spectrum of core components of CR, such as lipid and diabetes management, nutrition, psychosocial support, and smoking cessation [39]. Given the importance of contextual factors in shaping intervention uptake and effectiveness, interventions should be adapted to local, regional, and national circumstances. Co-designing interventions within users’ own context can help ensure that the intervention is aligned with user needs, priorities, and implementation conditions [10,36]. Our iterative co-creation process identified 5 themes of importance for stakeholders in meeting the end users’ needs. These themes included a tailored solution, options for feedback, peer support, digital reminders, and motivational features. Areas for improvement regarding the 5 themes were identified through contextual inquiries, stakeholder workshops, and iterative content development based on evidence-based strategies for CR. In general, ways to optimize the co-creation process from a user perspective are missing [10], and our results suggest avenues for shaping the process through the use of moderators, guidance, and continuous engagement.

This study highlights the importance of thorough patient involvement in co-creation sessions over an extended period. Such engagement is not merely beneficial but essential for understanding and integrating the needs and contexts of intended users [40], emphasizing how critical it is to prioritize user perspectives in the development of effective eHealth solutions [41,42]. A recent systematic review [41] identified usability and user-friendliness as prominent technology-related factors for health care professionals’ adoption of digital health interventions. This underscores the value of co-design methodologies in developing interventions that are both acceptable and implementable in clinical practice. Continuous patient involvement is essential not only for maintaining engagement but also for building trust and ensuring that participants feel safe and valued throughout the process [42]. It enabled users to address the core needs for a tailored solution, including options for feedback, peer support, digital reminders, and motivational features. Adopting a tailored approach is crucial for enhancing digital CR programs [43]. Engaging patients throughout the co-creation trajectory enabled the collection of essential feedback that informed the design decisions. The MRC framework [18] emphasizes that meaningful engagement of patients can maximize the potential of novel interventions that are likely to positively affect health. Empirical evidence substantiates that active user participation in development enhances the likelihood of successful adoption and seamless integration into users’ daily lives [11,44]. Furthermore, user involvement serves to diminish barriers to technology adoption, fostering a sense of ownership and agency among users, both of which are crucial determinants of the sustainability and effectiveness of a digital CR program [45].

Patient and public involvement is essential when developing eHealth interventions [18]. We initiated the co-creation process involving stakeholders in workshops using personas, which are fictional representations of characteristic real users [27], to better target the end users’ needs. The deployment of personas can function as an instrumental mechanism for acquiring a nuanced understanding of the user experience, fostering empathy, and elucidating user needs [46]. We constructed robust personas that helped focus the stakeholder workshops on the actual needs and goals of patients. A co-creation process is time-consuming due to the necessity for multiple feedback cycles, and it requires significant resources, both financial and human [11]. The use of personas may contribute to less extensive processes and contribute to the enhancement of self-management behaviors in digital CR [47]. This program was developed to engage a broad range of users, promote diversity, and address inequities in eHealth solutions [48]. Personas may elucidate how diverse patient demographics—such as women, older adults, or individuals with multiple comorbidities (persona 1)—exhibit heterogeneous requirements that necessitate tailored CR programs. Personas may also help narrow the design options, thereby enhancing the effectiveness of co-creation processes [36]. Using personas may also facilitate deeper user engagement, thereby advancing the overall user experience when developing a digital CR program [27].

The active user participation throughout the design process, with a diverse and representative group, is a strength that can lead to increased adoption and advocacy of the program. The same principal investigator (PI) and team followed the process and supervised all development phases, ensuring continuity in all aspects. The PRO-Ethics framework [34] was essential in enabling meaningful engagement and ensuring that participants’ perspectives were genuinely integrated into the development process.

However, this process was not without challenges. Despite strong user involvement, users may lack the technical expertise to provide insightful feedback on all aspects of the design. Therefore, while co-creation holds substantial promise for driving innovation and fostering user-centered design, it necessitates careful management to balance its benefits against inherent challenges.

One key issue is that eHealth approaches are not finalized after a pilot or main trial, but need a strategy for co-creation and revision across the full life cycle. As co-creation processes continue to evolve, there are several future directions to enhance their effectiveness and impact on health service development. One promising avenue is the integration of advanced technologies, such as AI and machine learning, into co-creation platforms in health care [49]. These technologies have the potential to analyze user data more effectively, providing objective insights that can help tailor the co-creation experience by identifying patterns beyond and across individual user preferences and behaviors.

This study offers insights into how to take a user-centered approach to the design and development of an evidence-based digital CR program to secure a tailored solution. The study involved stakeholders and users in all the phases of the iterative process, pointing out important steps for developing useful and meaningful interventions for patients using stakeholder workshops and co-creation sessions. In addition, to inform the development process, this study provides a practical example for future studies. Co-creation sessions with patient engagement over an extended period and the use of personas are recommended. To test usability, feasibility, and acceptability, as well as the potential efficacy of the program, further research is needed. A feasibility study is currently underway to optimize eCardiacRehab in preparation for a full-scale randomized controlled trial.