Developing a User-Centered Mobile Application Prototype: Bridging Lower-Limb Fracture Care from Skilled Nursing Facility and Back to the Community

Abstract

This study is part of the OsteoPorotic fracTure preventION System (OPTIONS) project which aims to develop an evidence-based mobile application for older adults transitioning from skilled nursing facilities (SNFs) back to the community after lower limb fractures. The app promotes exercise, nutrition, and bone health medications to prevent future fractures. Using a Design science framework, app requirements were identified by synthesizing scientific knowledge, clinical expertise, and end-user needs. An initial mockup was developed based on these specifications and iteratively refined through design sessions incorporating end-user feedback. The final OPTIONS app features four core functions: (1) task-based self-management support, (2) personalized exercises and education, (3) motivational messaging, and (4) progress tracking allowing users to monitor their progress through visualizations. By addressing usability challenges for older adults, the app provides a personalized, engaging experience for continuous health management.

Introduction

Osteoporosis is a common age-related disorder with substantial health and economic consequences. It is the leading cause of more than two million fragility fractures each year, often resulting in disability, nursing home admissions, and increased risk of morbidity and mortality^1-7. The economic burden of these fractures reaches an estimated $57 billion⁸, and the number of individuals affected by osteoporosis is projected to rise in the U.S.. Despite this growing prevalence, evidence suggests a gap in ensuring the continuity of care, including transitions through skilled nursing facilities (SNFs) to community settings (home health, primary care, and self-care)^9,10. Moreover, there is large variation in the standard of care for patients with fragility fractures receiving rehabilitation in SNFs. This highlights the need for evidence-based, coordinated care models for patients, clinicians, and caregivers to support older adults maintaining rehabilitation gains and reducing the risk of future fractures as they transition from SNFs back to the community.

We initiated the OPTIONS study (OsteoPorotic fracTure preventION System) to develop and provide an evidence-based, trimodal intervention for older adults within the first year following a lower limb fracture. This study focuses on individuals who are 65 and older and entered SNFs for rehabilitation and transitioned back to the community. The intervention which will be delivered in SNFs across the U.S. target three key areas: (1) exercise programs, (2) healthy nutrition, and (3) bone health medication management. The intervention is designed to improve bone health by integrating clinical decision support (CDS) for healthcare providers and educating and training for patients, caregivers, and healthcare providers. Additionally, educational materials will be provided in both high-tech (e.g., a mobile application) and low-tech (paper-based workbook) formats to ensure participants can continue engaging with the OPTIONS program post-discharge and reinforce the content provided in SNF. By providing these three components, the study aims to enhance patient’s functional status and quality of life throughout SNF and community care transitions.

As part of the larger OPTIONS study, our research focuses on developing the OPTIONS mobile application (app) for older adults transitioning from SNFs to the community. Successful app development requires addressing two primary considerations: (1) the variability in care for patients with fragility fractures within SNFs, and (2) the challenges older adults often face when adopting new technologies. Ensuring real-world usability necessitates a deep understanding of older users’ needs and preferences and the technical feasibility of integrating evidence-based app content. To meet these needs, we adopt the Design science framework, which incorporates scientific knowledge and clinical expertise into design science activities to develop a user-centered app¹¹. Central to this process are three iterative and interrelated cycles: the Relevance Cycle (identifying real-world problems and stakeholder needs), the Rigor Cycle (incorporating scientific foundations and domain knowledge), and the Design Cycle (iteratively creating and refining the technological artifacts). By continually engaging in these cycles, we strive to ensure that the OPTIONS app remains evidence-based, clinically relevant, and user-friendly. Our goal is to develop an OPTIONS app prototype within the Design science framework to bridge the continuum of care after SNF discharge.

Methods

Team and Study Setting

The study team consisted of multi-disciplinary experts, organized into five expert teams and led by the study’s two Principal Investigators. The composition of each team was as follows: the exercise team, the nutrition team, the bone health medication team, the app development team, and a human factors expert. Each team comprised specialists in their respective fields, including nurses, physicians, bone health experts, dietitians, physical therapists, and gerontologists who contributed their expertise in clinical practice, research, and app development.

The overall study process and its corresponding cycles within the Design science framework are illustrated in Figure 1. The study begins with establishing app requirements, followed by developing an initial app mockup based on these specifications. Subsequently, we actively incorporate user feedback through iterative design sessions to develop and refine the app prototype, progressing to before the stage of a fully functional prototype.

1. Development of App Requirements

   A multi-phase research approach was employed by integrating scientific knowledge, clinical domain expertise, and end-user requirements to derive the app requirements. To identify scientific evidence, we conducted a scoping review across the three key domains. To capture the needs from the clinical domain, we held focus group interviews (FGIs) with healthcare providers in SNFs and conducted a Professional Stakeholders’ Board meeting. To capture end-user needs, we conducted a Patient Stakeholders’ Board meeting and incorporated findings from our previous studies that identified end-user requirements for developing the eSTEPS app for older adults^12,13. Finally, we synthesized these findings through team discussions to develop app requirements appropriate for older adults.

   The exercise, nutrition, and bone health medications teams independently conducted scoping reviews to identify the latest evidence-based knowledge. The literature search was performed across four database: OVID Medline, Embase, Web of Science, and CINAHL. Table 1 presents the key questions for each domain, along with the key search terms, study inclusion and exclusion criteria. Following the scoping review, we held team meetings focused on the three components, who reviewed the findings and extracted key information relevant to patient education about the OPTIONS app’s contents or services.

   For the FGIs, we invited voluntary participants and healthcare providers from 20 SNFs affiliated with two collaborating institutions across the U.S. The interview questions were guided by the aims and purpose of the app and were designed to explore the three key domains: the current standard of care for lower limb fracture, the ideal care model, including perceived facilitators and barriers to its implementation, and strategies to ensure continuous care after discharge. We conducted a content analysis using Atlas.ti software, employing both inductive and deductive coding approaches. The identified themes were validated through intercoder reliability checks.

   Additionally, we conducted a Professional Stakeholders’ Board meeting with a panel of 12 international experts. This group encompassed professionals from diverse fields, representing areas such as geriatric and fragility fractures, hip fracture rehabilitation, bone health and osteoporosis, orthopedics, and physical therapy. The discussions focused on providing academic advice on the study’s content and direction and evaluating its clinical relevance and practical feasibility. For the Patient Stakeholders’ Board meeting, the panel consisted of 11 members including seven patients, family care partners, and four clinical care partners working with older adults after a fragility fracture participated.

2. Development of App Prototype

   1. Initial app mockup development
      We initially developed the eSTEPS app using a participatory design process involving community-dwelling older adults. The app served as the foundation for the initial app mock-up in this study. We then refined and expanded it to incorporate additional features specifically designed to support older adults in improving bone health after experiencing a fragility fracture^12,13. The app development team converted app requirements into a functional app.
   2. Design sessions
      Based on the initial mockup, we continuously refined the design through an iterative improvement process by incorporating user feedback. This involved repeated team-based design sessions where the three key domain teams collaborated with a human factors expert to integrate user feedback and enhance usability and accessibility for older adults. Simultaneously, the domain teams worked with the app development team to assess technical feasibility and proceeded with development accordingly.

3. User Feedback

   Patient feedback was gathered through both large-group and small-group discussions. Large-group feedback was obtained at the Patient Stakeholders’ Board meeting and small-group feedback was collected through the Patient Operation Team Meetings, which consisted of four patients and family care partners with diverse experiences, including those who had experienced falls and served as patient advisors in hospital settings.

   To observe older adults’ reactions and collect feedback, we simulated real post-discharge scenarios and provided a mockup to assess how participants would interact with the app in such situations in both discussions. Additionally, to collect feedback and minimize bias, we presented mock-up screens without explanation and asked questions such as, “What do you think this app is used for?” or “What action would you take on this screen?” to gauge their natural understanding of the app.

Figure 1.

Study process following the Design science framework

Table 1.

Study questions and criteria for the scoping review of three key domains

Study Questions	Exercise: Exercise and physical activity for secondary fracture prevention in elderly adults with osteoporosis Nutrition: The association between nutritional interventions and fractures in elderly patients Bone health medication: Barriers and facilitators to access to bone health medications by elderly patients with osteoporosis in the U.S.
Date restrictions	Exercise and Nutrition: No date restrictions were applied Bone health medication: Year 2014-2023
Key search terms	General for three domains: Older population, patients with fractures and secondary prevention Exercise: Exercise and physical activity Nutrition: Diet and nutritional intervention, randomized controlled trial or controlled clinical trial Bone health medication: Osteoporosis and bone health medications, patient adherence
Inclusion criteria	Age >60 AND mean age >65 with lower limb fracture Outcome: [Exercise, nutrition]: Physical function, quality of life, falls, fractures, mortality [Bone health medication]: Factors influencing access to bone health medication. Include interventions (nutritional interventions, physical activity, bone health medications)
Exclusion criteria	Studies not published in English Studies without full-text availability

Results

We finalized the OPTIONS app requirements by synthesizing scientific knowledge, clinical domain expertise, and end-user needs (Table 2). The scoping review included a final selection of 28 studies on exercise, 24 studies on nutrition, and 30 studies on bone health medication. Additionally, we conducted nine FGIs with 18 healthcare providers, including 7 nurses, 9 physical therapists, and 2 physicians. A Professional Stakeholders’ Board meeting was held with 12 attendees, and a Patient Stakeholders’ Board meeting were conducted with 10 attendees (Detailed results from the scoping review and FGIs will be presented in a separate study; here, we focus on findings relevant to app requirement development). Both FGIs and board meetings were conducted virtually via Microsoft Teams or Zoom and lasted approximately an hour.

Table 2.

App requirements derived from scientific knowledge, clinical domain expertise, and end-user needs

Table 2 outlines how each of the three key domains informing the app requirements was developed through the integration of three approaches: clinical evidence from the scoping review, practical challenges encountered in real-world care settings from the clinical domain experts, and priorities regarding app design and functions identified by prospective end users. The ‘App requirements’ column in Table 2 summarizes the content and design elements to be incorporated into the app based on this integrated input. For the exercise section, the app will provide tailored exercise programs based on users’ health conditions with video and handout materials. In the nutrition section, the app will track weight-loss trends, assess nutritional status and eating habits, and provide personalized education accordingly. Regarding bone health medications, the app will include a medication intake reminder function, help users assess their risk of fractures, and provide multi-format video education sessions to enhance adherence and understanding of osteoporosis.

Based on the app requirements, the initial mock-up was developed and progressively refined through user feedback (Figure 2). Feedback was gathered over time through five small meetings and two large meetings. Participants emphasized the need for a simple, user-friendly app with clear language, standardized formatting, and a streamlined design, as well as the importance of self-management support (Table 3).

Figure 2.

Changes in the App home screen design in the initial mock-up

Table 3.

Summary of feedback from user-perspective

Ensure the app is simple and user-friendly Standardize the order and color coding for three key domains Aim for reading level equivalent to third-grade student Use short, clear, and positive language Simplify the app design Support continuous self-management Ensure the app is self-manageable, allowing users to track and maintain their own progress Separate daily and weekly tasks Limit each tab to one task per day/week. Specify clear timeframes for task completion. Enhance user engagement Visualize task progress, personal health status, or improvements Provide rewards or acknowledgements upon task completion

This feedback also served as the foundation for establishing the four core functionalities of the app prototype (Figure 3). These four core functionalities include: (1) The task management that enables older adults to actively self-manage the three key domains, (2) Personalization that provides customized exercise programs and educational content, messages tailored to individual users, (3) Motivational content where users receive encouraging messages upon completing assigned tasks, and (4) Progress tracking that allows users to monitor their progress and trends through visualizations.

Figure 3.

OPTIONS App prototype and its core functionality

Discussion

We develop an OPTIONS app prototype to provide evidence-based post–lower-limb fracture care in three key domains—exercise, nutrition, and bone health medication—to older adults transitioning from SNFs to community settings. The app development process follows a Design science framework, which serves as the methodological foundation for creating a user-centered app.

A user-centered design approach is particularly critical when developing apps for older adults, as many in this population face barriers that make app usage challenging¹⁴. Nevertheless, smartphone adoption among older adults is significant—76% of those aged 65 and older in the United States now use smartphones¹⁵. Although some older adults still find smartphones difficult to use, this high adoption rate suggests that a mobile app may serve as a valuable tool for managing bone health in daily life. To address usability challenges and maximize efficiency, we actively incorporated patient feedback into the design phase. This process led to the establishment of the app’s four core functionalities: (1) task management, (2) personalization, (3) motivational content, and (4) progress tracking feature. The task management features prompts continuous self-management by offering tasks throughout the 45-week study period. For exercise, daily personalized exercise programs will be provided, while nutrition and bone health medication tasks are intended to be scheduled weekly. The exercise section is designed to use a logic-based system to assess the user’s condition and generate personalized daily exercise programs tailored to their needs. Similarly, the nutrition section aims to offer individualized education based on users’ nutritional status, weight-loss trends, and eating habits, utilizing various resources to ensure personalized guidance. For the bone health medication section, a weekly task is planned to include multi-format video education sessions followed by a quiz. As a part of these tasks, users’ bone health is expected to be assessed, with personalized messages provided based on their responses. The motivational content includes encouraging messages upon task completion and incorporates a reward system designed to promote sustained user engagement. Users can earn e-hearts for exercise and e-diamonds for bone health medication section to sustain engagement. Finally, the progress tracking feature is included to visualize cumulative trends keeping users motivated and engaged. Together, these four core features are intended to offer a personalized, intuitive experience that fosters continuous health management.

By leveraging the eSTEPS app as the foundation for our initial mock-up, we can incorporate core functionalities and more readily adapt to previously unmet user demands—such as task assignment, progress tracking, and reward systems (e.g., e-hearts for task completion). Moreover, the four core functionalities—a task management¹⁸, personalization^19-23, motivational content²⁴, and progress tracking feature²⁵ —have been shown to enhance the effectiveness of health promotion programs and improve adherence in older adults¹⁹.

A multidisciplinary collaboration with domain experts and stakeholders ensures development of evidence-based app content, while cooperation with a human factor’s expert and the app development team enables the continuous integration of user feedback.^16,17 This collaborative effort resulted in the development of the OPTIONS app prototype; a professional, patient-centered solution designed to support the continuous care of older adults recovering from lower limb fractures following SNF discharge. Our next step is to conduct additional usability testing with older adults to evaluate the production version of the app for further refinement. Subsequently, a pilot study will evaluate the app’s real-world use and effectiveness in bridging lower-limb fracture care from SNF and to the community.

Limitations

This study has several limitations. First, as the app was designed for SNF-to-community transition in two large SNF institutions in the U.S., its generalizability to other institutions is unclear. However, since these institutions operate across different regions of the country, there is potential for broader applicability in the future. Second, as the app remains in the prototype design and development stage, usability testing has not yet been conducted. Future research should assess usability with older adults, evaluate real-world user outcomes and effectiveness, and explore specific use cases demonstrating how users would interact with the app in practical settings. This process will ensure that the app effectively supports continuous post-discharge care to improve bone health management.

Conclusions

The Design science framework facilitated the development of a comprehensive OPTIONS app prototype that supports exercise, nutrition, and bone health medication management for older adults transitioning from lower limb fracture rehabilitation at SNFs back to the community. By integrating evidence-based content with practical insights from domain experts and incorporating patient feedback throughout the design process, we created an interactive and engaging app. This prototype has the potential to enhance continuous post-discharge care, promote self-management, and improve health outcomes. Moreover, it highlights the importance of interdisciplinary collaboration among clinical and human factors experts, and app developers in creating patient-centered digital health solutions.