The FDA issued a new guidance, Applying Human Factors and Usability Engineering to Medical Devices in early Feb 2016. On April 3, 2016, it will replace Medical Device Use-Safety: Incorporating Human Factors Engineering into Risk Management issued in 2000. This lengthy document (49 pages) contains some very specific language on how human factors should be incorporated into medical device product development, risk management, and on how human factors should be validated.
While this is a guidance document, it represents the current FDA direction on human factors. In addition, CDRH has released a draft guidance document, List of Highest Priority Devices for Human Factors Review, Draft Guidance for Industry and Food and Drug Administration Staff, to clarify CDRH’s expectations regarding which device types should include human factors data in premarket submissions.
- The primary focus is on use related hazards and incorporation into the risk management process. It includes the necessary elimination or reduction based on your risk management process. Documentation is expected to demonstrate that you considered the needs of intended users in the design of the device and determined that the device is safe and effective for the intended users, uses, and use environments.
- You are expected to characterize the device users, the device use environment, and the device user interface. Each of these are detailed in the guidance.
- While the formal documentation begins with the risk management file, it is clear, that the device designers should be considering the characteristics prior to design controls (for example, early activities to understand the customer needs and evaluation of early product concepts).
- Several sections are included to help product developers identify use related hazards or specific points where they could occur.
- Human factors validation testing (Section 8) appears to represent the most significant change for product development. Design verification and validation use structured protocols, often in controlled environments, allowing intervention when the device might be improperly used. In human factors testing, you are looking for use in a user like setting, providing typical training that the user would receive, and watching how it is used. The observer captures what was done correctly, as well as, how it was used incorrectly or almost used incorrectly (close calls). Those observations may lead to further product changes. For products that could be used in multiple settings or by different user groups, you are expected to test in the different settings using representative users for those settings. Below are a couple examples.
- A product which will be used by both adults and pediatric users should include testing by both user groups.
- A device which could be used in a hospital, skilled nursing facility, and at home represents 3 distinct user environments and 2 distinct user groups. Human factors validation testing is expected to cover these unique situations.
Additional expectations for participant interviews and example questions are included in the guidance.
- Sample size considerations are covered in Appendix B. Table C.1 contains hypothetical sample results of human factors validation test analyses. While the results are hypothetical, the columns “Medical device use task” and “Hypothetical Task Failure” appear to come from actual medical device reports (MDRs).
- FDA encourages manufacturers to submit a draft of the HF validation protocol to them through the Requests for Feedback on Medical Device Submissions: The Pre-Submission Program and Meetings with Food and Drug Administration Staff
Human factors are important to overall medical device safety. While a guidance document, often they set the expectations for product development testing and inclusion in the device design history file (DHF). The changes included in the guidance document need to be evaluated and included in each medical device company’s product development process so that human factors are appropriately integrated into your products.