USFDA Guidance: Content of Human Factors Information in Medical Device Marketing Submissions

Human factors engineering focuses on understanding how users interact with medical devices and applying that knowledge to design safer and more effective products. The FDA explains that user interface design can significantly impact patient safety, as user errors may lead to incorrect treatment, delayed therapy, compromised medical care, or patient harm.

Manufacturers routinely perform human factors assessments during device development to identify and mitigate use-related risks. The purpose of this guidance is to establish a risk-based framework that helps manufacturers determine the type and level of human factors information that should accompany a marketing submission.

Scope of the Guidance

The guidance applies to medical devices regulated by the FDA’s Center for Devices and Radiological Health (CDRH), including:

• Premarket Notifications (510(k))

• Premarket Approval Applications (PMAs)

• De Novo Classification Requests

• Humanitarian Device Exemption (HDE) Applications

The recommendations are intended to be broadly applicable across medical device types and are designed to help both manufacturers and FDA reviewers determine the appropriate level of human factors information needed to support marketing authorization.

Importance of Human Factors Engineering

The FDA emphasizes that a well-designed user interface is essential for ensuring safe and effective device use. Human factors engineering seeks to identify and reduce use-related risks that may occur when healthcare professionals, patients, or caregivers interact with a device.

The ultimate goal is to design devices that can be used correctly and consistently by intended users under expected conditions of use. Human factors assessments help manufacturers understand how users perceive information, perform tasks, interpret instructions, and respond to device feedback.

By addressing usability concerns early in development, manufacturers can reduce the likelihood of use errors and improve overall device safety. The guidance also defines concepts such as hazards, hazardous situations, residual risk, use environments, use safety, and use-related risk analysis, all of which play important roles in evaluating device usability.

Risk-Based Approach to Human Factors Information

A major feature of the guidance is the introduction of a risk-based approach for determining the amount of human factors information that should be included in a marketing submission.

The FDA explains that not every device requires the same level of human factors documentation. Instead, the level of information should be based on factors such as:

• Presence of critical tasks

• Device complexity

• User interface modifications

• Intended users

• Intended use environments

• Existing risk control measures

• History of safe use

This approach is intended to align regulatory expectations with the level of use-related risk associated with the device.

Human Factors Submission Categories

The guidance introduces three Human Factors (HF) Submission Categories that determine the extent of information expected within a marketing submission.

HF Submission Category 1

Category 1 applies to modifications that do not affect human factors considerations. Examples may include software algorithm updates or internal technical changes that do not alter the user interface, intended users, intended uses, labeling, training, or use environment.

For these submissions, manufacturers are expected to provide a conclusion and high-level summary explaining why the modifications do not impact human factors considerations.

This category represents the least extensive level of human factors documentation.

HF Submission Category 2

Category 2 applies when modifications affect the user interface, labeling, training, or other human factors elements but do not introduce new critical tasks or impact existing critical tasks.

In these situations, manufacturers are expected to provide a rationale explaining why additional human factors validation testing is not necessary.

The submission should include supporting analyses demonstrating that use-related risks remain adequately controlled.

HF Submission Category 3

Category 3 applies when new critical tasks are introduced or when existing critical tasks are impacted by device modifications. This category generally requires the most comprehensive level of human factors documentation.

Manufacturers are expected to submit a complete Human Factors Engineering and Usability Engineering (HFE/UE) Report, including human factors validation testing data.

The report should demonstrate that users can safely and effectively perform critical tasks under expected conditions of use.

Determining Human Factors Submission Categories

The FDA provides a structured decision-making process that guides manufacturers through a series of questions.

The process begins by determining whether the submission involves a new device or a modification to an existing device. Manufacturers then evaluate whether there are changes to:

• User interfaces

• Intended users

• Intended uses

• Use environments

• Training

• Labeling

If such changes exist, manufacturers must assess whether critical tasks are introduced or impacted. This evaluation is supported through a Use-Related Risk Analysis (URRA), which serves as a foundation for determining the appropriate submission category.

The FDA emphasizes that modifications should be assessed holistically, considering cumulative impacts rather than evaluating individual changes in isolation.

Use-Related Risk Analysis (URRA)

The guidance identifies the Use-Related Risk Analysis (URRA) as a key component of human factors evaluation.

The URRA is a systematic process used to identify hazards associated with device use and assess potential use-related risks. It helps manufacturers understand how users may interact with a device and where use errors could occur.

The FDA recommends that URRAs include:

• User tasks

• Potential use errors

• Hazardous situations

• Potential harms

• Severity assessments

• Critical task identification

• Risk control measures

• Validation methods

The URRA should be maintained throughout device development and updated as new information becomes available.

For modified devices, manufacturers are encouraged to compare the revised URRA with the existing device URRA to assess whether changes affect critical tasks or risk controls.

Human Factors Validation Testing

For devices that fall within Category 3, human factors validation testing is a critical regulatory expectation.

The purpose of validation testing is to determine whether intended users can successfully perform critical tasks using the final device design without experiencing serious use-related problems.

The guidance recommends that validation testing evaluate:

• Realistic use scenarios

• Intended users

• Intended use environments

• Critical tasks

• Risk control effectiveness

• Potential use errors

Manufacturers should document observations, user feedback, task performance, use errors, and any residual risks identified during testing.

The FDA notes that validation testing may be conducted using simulated-use environments, actual-use environments, or clinical studies, depending on the nature of the device and associated risks.

The guidance represents an important step toward more consistent, efficient, and evidence-based evaluation of usability within the medical device regulatory process.

References

Content of Human Factors Information in Medical Device Marketing Submissions