Effective communication between patients and medical professionals is essential for achieving positive treatment outcomes [1]. Shared decision-making (SDM) is a collaborative approach that integrates expert medical knowledge with patient preferences to make informed decisions [2,3]. In 2010, OpenNotes—an online patient portal providing shared access to physicians’ notes—was launched in the United States, enabling patients to easily review electronic medical records created by medical staff for clinical communication [4,5]. Studies have explored the perceptions and attitudes of both the general public and hospital workers toward medical records [6,7]. Recently, as part of research focused on the “Smart Patients” concept, definitions and methods for applying SDM and OpenNotes in Korea have been actively discussed.

For successful rehabilitation, quality interactions, efficient provision and collection of information, recognition of patient interests and goals, and reinforcement of health-related behaviors are vital [8]. Mobile applications are increasingly used to monitor chronic diseases and support diagnosis and treatment, including rehabilitation [9]. However, existing platforms in Korea (e.g., MyHealthWay) do not provide patients access to doctor-authored notes, which limits patient-physician interaction. Patients frequently use web-based platforms and mobile apps to share personal health information, yet finding a platform or application enabling patients to review their own health records written by physicians remains challenging.

Therefore, the objective of this study was to develop a mobile application facilitating effective communication between rehabilitation patients and physicians based on the SDM model, thereby delivering patient-centered rehabilitation services and ultimately improving rehabilitation treatment outcomes.

The phrase “shared decision-making” was first introduced by Veatch [10] in 1972 and has evolved into a collaborative decision-making approach among patients, physicians, and family members. SDM occurs when decisions need to be made jointly by doctors and patients. It represents a beneficial collaborative method in which the best available evidence is shared, and patients are supported in considering various options to formulate informed preferences [11]. SDM encompasses open communication, information exchange, and the consideration of patient preferences and values, ultimately leading to a joint decision that respects patient autonomy while leveraging healthcare professionals’ expertise.

Several studies have described the essential elements of SDM [3,12–15], but Stiggelbout et al. [16] specifically outlined four key steps: informing the patient, explaining options, discussing patient preferences, and making a decision.

Benefits associated with SDM include increased patient satisfaction, decisions that align better with patient values, reduced stress, and more appropriate treatment choices. SDM is particularly valuable in contexts where multiple treatment options exist, as it fosters trust and open communication. This ethical and patient-centered approach enhances the overall quality of medical decision-making.

In-depth interviews were conducted with two physicians specializing in rehabilitation, treatment, and patient management. These were one-on-one interviews utilizing a semi-structured questionnaire, held at the participants’ preferred times and locations. Each interview lasted between 40 and 60 minutes. Key questions explored included the general rehabilitation treatment process, criteria for participant selection, specific services provided according to rehabilitation classification, information necessary for rehabilitation treatment and management, preferred methods of communication with patients and guardians, and functions required for the app implementation. All interviews were recorded, transcribed verbatim, and systematically organized.

In this study, the E4 model—a healthcare communication model—was utilized, incorporating the concepts represented by the four E’s: Engage, Empathize, Educate, and Enlist. Accordingly, REHAB NOTE was designed to create an interactive environment for communication between patients and doctors, emphasize empathy for patients, deliver education and information grounded in empathetic understanding, and encourage active patient feedback.

This phase involved defining the relationships between various components of the user interface within the application. As REHAB NOTE comprises multiple pages, a navigation design diagram was created, clearly illustrating the linkages between pages and specifying data migration paths across pages.

During this phase, the screen layouts and functions of each application page were carefully designed. For the REHAB NOTE application, detailed content descriptions and comprehensive page design diagrams were produced to clearly visualize each screen’s features and layout.

The in-depth interviews revealed several important findings. Due to disease specificity and situational uniqueness, patients often lack information regarding rehabilitation treatment approaches and post-discharge management, indicating a strong need to develop services that support effective communication. Particularly, patients undergoing rehabilitation for CNS injuries frequently experience cognitive challenges, while cancer rehabilitation patients typically receive extensive amounts of complex information simultaneously, requiring complementary support strategies. Additionally, patients noted that the information provided when visiting different areas within the hospital could be confusing. Consequently, they sometimes recall incorrect information or management methods, adversely affecting the treatment process.

To address these issues, participants emphasized the necessity of services that improve communication, such as providing access to medical notes after discharge and enabling patients to document their health issues and inquiries. Furthermore, they highlighted the importance of efficiency and convenience in writing medical notes for patient use. The specific requirements for the REHAB NOTE application, derived from the interview content, are summarized in Table 1.

The architecture design diagram employing the E4 model is presented in Figure 1. The diagram clearly illustrates the flow of health-related information, including data input during physician and patient registration and login, medical notes entered by physicians, information accessible to patients, and symptoms or vital signs entered by patients.

During architectural design, the application’s primary objective was to establish an environment that facilitates communication between physicians and patients and implements a patient-centered user experience (UI/UX) for collecting patient-related data. Additionally, the design ensured patients receive the necessary information and are actively encouraged to provide feedback.

The linking relationships and data migration pathways between pages in the REHAB NOTE application are illustrated in Figure 2. Patients and doctors initially apply for membership, after which they can log in upon administrator approval. The doctor’s interface enables selection of patients from a patient list, addition or deletion of patient records, inputting medical notes, and reviewing and modifying patient data. Patients can review information entered by doctors. On the patient interface, patients can access the medical notes entered by physicians, as well as input and manage their health status information.

The screen layouts and specific functions for each page within the REHAB NOTE application are presented in Figure 3. A total of 27 user interface and administrator screens were designed in this study. In November 2022, an installation file (version 0.0.3) was delivered to the application developer and subsequently installed on the researchers’ smartphones for trial operations. The final development version (0.0.4) was completed in December 2022 after adjustments, including repositioning buttons for enhanced usability, revising the rehabilitation treatment list, and supplementing dropdown menu contents when recording medical notes.