Findings
While verification, analytical validation, and clinical validation have been well-established, usability validation has not been systematically incorporated into digital health technology evaluation.
Variability in device designs, patient populations, and regulatory environments creates barriers to widespread adoption of sensor-based digital health technologies.
Usability problems, such as poor user interfaces and technical errors, can lead to significant data loss in clinical trials and real-world applications.
While some guidance exists for usability in medical devices, there is no unified global standard for assessing usability in digital health products, leading to inconsistencies in implementation.
Stakeholders, including regulators, industry leaders, and researchers, recognize the need for usability validation to ensure the real-world effectiveness of digital health technologies.

Recommendations
Adopt the V3+ framework as a standardized method to ensure that usability is rigorously tested alongside verification, analytical validation, and clinical validation.
Establish clear protocols for usability testing, including use specification development, risk analysis, iterative formative evaluations, and summative evaluations.
Bring together regulators, technology developers, clinicians, and patients to create guidelines that ensure fit-for-purpose digital health solutions.
Work with regulatory agencies such as FDA, EMA, and MHRA to establish harmonized global standards for usability validation.
Encourage the publication of usability study results, including negative findings, to facilitate transparency and continuous improvement in digital health technologies.

Regulatory Considerations
Agencies like FDA and EMA increasingly require usability data for digital health technologies, but standardized methodologies are still evolving.
Usability validation should align with regulatory requirements for medical devices and digital biomarkers, ensuring clinical relevance and data integrity.
Digital health technologies must adhere to HIPAA, GDPR, and other data protection regulations while ensuring seamless usability.
Poor usability can lead to missing or unreliable data, which affects regulatory submissions and real-world evidence generation.
A consistent approach to usability evaluation is needed to support regulatory decision-making and digital health product approvals globally.

Findings
The Library of Human Factors Resources compiles external documents related to human factors, human-centered design, and usability in the context of Digital Health Technologies (DHTs), especially sensor-based DHTs (sDHTs). The resources in the library are categorized by usability validation activity:
Use-related risk assessment (topics include user tasks, use-errors, use-related hazards, and risk mitigation).
Design considerations (topics relate to product design).
Formative evaluation (topics related to usability evaluation of a prototype product).
Summative evaluation (topics related to usability evaluation of a final-version or marketed product).

Recommendations
The page recommends that users, developers, and evaluators utilize the library's interactive index to find relevant documents to their DHT:
Use the Search by Activity tab to filter by one of the usability validation activities listed above.
Use the human factors topic column to further narrow the search.
Review the document name, issuing body, and product of focus columns to identify the most relevant document.
Click the hyperlink to access the selected document, then use the information in the relevant sections column to locate the specific topics of interest.

Regulatory Considerations
The library is a collection of resources for accelerating sDHT adoption, and it specifically includes documents like regulatory guidance and industry standards. This emphasizes the importance of understanding and applying human factors principles for validation and achieving regulatory acceptance for sDHTs.

Findings
The V3+ Use Specification must contain a detailed description of the user groups, use environments, and the sDHT user interface. The user groups include end-users (individuals from whom data is captured) as well as carepartners, clinicians, researchers, and administrators. Characteristics of users (e.g., demographics, literacy, physical/cognitive capabilities, disease characteristics) and use environments (e.g., temperature, network availability, clutter) must be considered for risk management .

Recommendations
Developers must follow these four steps to create the Use Specification:
Identify all user groups: Create a list of users, including sub-categories (e.g., different types of researchers), and describe the characteristics of each group (e.g., health literacy, physical capabilities) to create detailed descriptions of representative users.
Identify all likely use environments: Create a list of typical environments (e.g., Home, Hospitals) and describe their characteristics (e.g., temperature, noise, network availability), also considering "edge cases" (e.g., extreme weather).
Describe the sDHT user interface: Detail all aspects of the hardware and software (visual, auditory, tactile cues), accessories (e.g., packaging, chargers), and all written materials and training (e.g., instructions for use, helpdesk troubleshooting).
Keep it up to date: The Use Specification is a living document that requires ongoing updates and maintenance throughout the sDHT development and usability validation process.

Regulatory Considerations
The development of the Use Specification is presented as the foundational step for the usability validation component of the V3+ framework. This document directly informs the subsequent Use-Related Risk Analysis.

Findings
The development of this standardized questionnaire highlights a critical gap in clinical research: the lack of a consistent method for collecting participant feedback. It implicitly finds that understanding the patient experience is essential for addressing issues like high dropout rates and patient burden. The tool's detailed sections suggest that factors from communication and scheduling to technology usability and visit burden are key determinants of a participant's trial experience.

Recommendations
The resource strongly recommends that sponsors and research sites proactively gather structured feedback directly from study participants. It advises using this tool to identify specific pain points in trial design and execution. The underlying recommendation is to adopt a more patient-centric and human-centered approach by integrating participant feedback into the continuous improvement of clinical trial protocols and operations, ultimately boosting recruitment and retention.

Regulatory Considerations
While not a formal regulatory guidance document, the tool supports the principles of patient-focused drug development (PFDD) encouraged by regulatory bodies like the FDA. Collecting data on the patient experience can help demonstrate that a trial's design and conduct minimizes undue burden and is ethically sound. This feedback can be a valuable component of submissions, illustrating a commitment to patient centricity and potentially improving the assessment of a trial's overall quality and integrity

Findings
Clinical trial protocols designed without patient input often result in a high participant burden and a poor patient experience, leading to challenges in trial enrollment, adherence, and retention.
A lack of early patient engagement can lead to study designs that are not feasible, collect data on outcomes that aren't meaningful to patients, and require costly protocol amendments later in the process.
Many sponsors and research teams lack a structured, systematic process and standardized tools for effectively planning and executing patient engagement activities.
Meaningful patient partnerships can lead to research of greater quality and relevance, as patients provide unique insights into living with their condition and the practicality of trial procedures.

Recommendations
Adopt a structured toolkit and systematic process to plan patient engagement, define objectives, select appropriate methods, and apply learnings to the protocol.
Engage with patients and caregivers as early as possible in the protocol development lifecycle to ensure their insights can meaningfully influence the study design.
Carefully select diverse patient partners based on criteria like their disease experience, and choose appropriate engagement methods (e.g., advisory boards, focus groups, surveys) to meet defined goals.
Use provided guides, templates, and visual aids to facilitate clear communication, manage expectations, and effectively gather, assess, and implement patient feedback.

Regulatory Considerations
Patient engagement in trial design is strongly encouraged by global regulatory bodies, including the U.S. Food and Drug Administration (FDA).
These activities align with regulatory initiatives like the FDA's Patient-Focused Drug Development (PFDD) guidance, which emphasizes collecting data that reflects patient experiences, needs, and priorities.
Incorporating patient feedback helps ensure that a clinical trial is designed to capture meaningful endpoints and outcomes, which supports subsequent regulatory and Health Technology Assessment (HTA) review.

Findings
Challenges related to data safety, quality, privacy, and regulatory requirements in smart sensor technologies.
Bias in standard RCTs due to exclusion of participants with language or motor barriers.
Need for ICT systems to detect smooth transitions in cognitive abilities and everyday functions.

Recommendations
Develop ICT-based procedures that capture relevant clinical features validly.
Ensure data fidelity and robustness in ICT systems.
Incorporate user needs into ICT solutions.
Address data safety and privacy concerns.
Develop international policies for access, security, and privacy in ICT solutions.

Regulatory Considerations
Need for international efforts to address gaps in policies around access, security, and privacy.
Current laws do not cover health information on mobile apps or the Internet.
Lack of regulation could undermine the credibility of RWE results.

Findings
Home use devices face unique environmental challenges, including power interruptions, fluid exposure, and travel-related conditions.
Lay users often have limited training and varying physical, cognitive, and emotional capabilities, requiring user-friendly designs and clear instructions.
Effective risk management should include designing risks out of the device wherever possible, supplemented by protective measures and labeling as needed.
Verification, validation, and human factors testing are essential to confirm device performance and usability under realistic home-use scenarios.
Postmarket considerations, such as customer service and Medical Device Reporting (MDR), are vital for maintaining device safety and compliance.

Recommendations
Design devices for diverse environmental conditions, such as variable power supplies, fluid exposure, and extreme temperatures.
Include safeguards like lock-out mechanisms, robust alarm systems, and protective casings to mitigate risks.
Develop user-friendly labeling and instructions, employing narrative formats and visuals to address low literacy or technical proficiency.
Conduct human factors engineering and usability testing to identify and resolve potential design issues, ensuring safe device operation by lay users.
Plan for postmarket support, including accessible customer service and robust systems for adverse event reporting.

Regulatory Considerations
Premarket submissions should document efforts to address environmental and user-related risks, supported by verification, validation, and usability data.
Devices requiring electrical power must meet applicable ANSI/AAMI standards for safety, including those related to electromagnetic compatibility.
Manufacturers must comply with labeling requirements under 21 CFR Parts 801 and 809, ensuring clear communication of warnings, instructions, and limitations.
FDA emphasizes the use of recognized consensus standards, such as IEC 62304 for software lifecycle processes and ANSI/AAMI HE75 for human factors engineering.
Devices must incorporate mechanisms for handling emergencies, including power outages, and provide clear labeling on disposal, maintenance, and troubleshooting.