5 User-Centered Design Strategies for Mobile Health Apps: Enhancing Usability, Safety, and Regulatory Approval

When regulatory authorities grant authorization for medical devices, both IEC 62366 and the FDA emphasize the importance of human factors and user-centered design in the development process to ensure device safety and enhance usability. The development of mobile health apps is no exception. Developers of mobile health apps are not merely creating applications akin to Angry Birds or Candy Crush; rather, they are building mobile medical device applications capable of monitoring users’ health status, diagnosing symptoms, and providing guidance during sudden medical emergencies.

Therefore, user-friendly mobile health apps, meticulously crafted by developers, meet the needs and expectations of target users while reducing the risk of user operational errors. This approach not only streamlines the CE marking and U.S. Food and Drug Administration (FDA) approval processes but also enhances customer adoption and satisfaction. When planning the development of a mobile health app, the following five user-centered design principles should be implemented to improve user experience and customer satisfaction.



1. Understand the intended use environment and user needs
User research requires the mobile health app development team to understand user needs and the problems that need to be addressed. User research involves directly observing potential users in their anticipated usage environments. When developing a mobile health app, medical experts can bring significant benefits to the members of the development team. Meanwhile, researchers may also need to acquire specific and extensive medical knowledge. By understanding user needs and their contexts, developers will have a better opportunity to integrate all necessary functions and information, thereby making the healthcare app more comprehensive and robust.

The findings from observational studies are documented in user scenarios and task analyses. A user scenario is a brief narrative describing a specific user with particular goals. Task analysis provides a detailed account of the steps required to fulfill the user scenario, addressing human needs. Both require plain language to build consensus among R&D team members and investors, and they are frequently applied in future user-centered design activities.

2. Analyze potential use risks and user errors
During use, the R&D team should concurrently conduct risk analysis and traditional systems analysis to identify potential risks between the app’s intended use and reasonably foreseeable misuse. Designers are responsible for creating workflows and interaction designs that prevent errors. If user errors do occur, the mobile health app should incorporate rapid recovery mechanisms in its design. Additionally, designers should recognize that input methods on mobile devices differ from those on desktop computers, and new users may require more time to become familiar with the app.

Differences in the age, cognitive ability, lifestyle, digital literacy, and health literacy of target users can all affect their proficiency in using mobile apps and lead to errors. If the target user base includes both young, healthy tech-savvy individuals and elderly or disabled users with physical limitations, developers must ensure that both groups can effectively use mobile health apps.

3. The design model aligns with user habits
By adopting the following approaches, application designers can ensure that app designs align with user habits:
● Focus on the user's primary work and basic tasks
● Ensure users can complete tasks with ease
● To achieve user goals, multi-step processes need to be designed.

Many users are already accustomed to non-medical mobile apps and expect the same level of navigation and interactivity. App developers benefit from currently industry-recognized dynamic UI design paradigms for navigation and interaction. The provided intuitive and straightforward experience makes it easy for users to learn and remember. It is well known that users will not invest significant time in learning new, complex interaction patterns, especially in the era of mobile internet, where few users read manuals or help pages.

Designers who understand the principles of interactive design are essential for executing efficient mobile interaction design. Interactive design enables users to enjoy an optimal visual experience and clear navigation when accessing and using apps. By minimizing panning and zooming, optimizing screen dimensions, and facilitating user navigation, interactive design enhances usability.

4. Iterative Design (Prototyping, Testing, Refinement, and Repetition)）
Iterative design methods make the user interface of mobile health apps more intuitive and easier to use. They can also control or mitigate potential risks. Iterative design is a design process involving prototyping, testing, analysis, and optimization, requiring early insights and feedback.
Therefore, any issues can be addressed promptly, allowing for iteration and adjustments before reaching the final design; it is crucial to do this as early as possible. Repeated updates and iterations help minimize errors and problems.
Usability testing aims to gather feedback from potential users on prototypes; this process may be relatively short in duration and involve a small number of participants. Some apps require representative users to evaluate the product and provide key insights. Initial testing can rapidly identify most potential issues.

5. Verify Clinical Efficacy
Final clinical testing demonstrated that the product is safe and effective for its intended use, users, and usage environment. This also confirms the validity of the design, which in practice reduces risks associated with its use. The representative user sample should include all individuals who have tested the mobile health app, potentially encompassing healthcare institutions, administrators, patients, and caregivers.

Summary testing has already become part of iterative design activities. Summary testing should truly play the final role in ensuring the safe use of devices, as from a risk perspective, test usage scenarios should focus on critical and important tasks.

A user-centered design philosophy should permeate the entire development lifecycle of mobile health apps, encompassing research on new users, task and risk analysis, iterative design and evaluation, as well as all summative validation testing conducted in simulated use environments during the final stage. Although this approach may necessitate a more rigorous development pathway than creating the next Angry Birds or Candy Crush app, it facilitates regulatory approval, mitigates the risk of user operation errors, and enhances customer satisfaction.

Translation: Liu Jianqiu

Responsible Editor: Zhang Nan