FDA plans to "be much more specific" about the types of devices that will be subject to human factors data expectations when it finalizes a guidance on the topic, according to a device center staffer.

Molly Follette Story, a human factors and accessible medical technology specialist in CDRH’s Office of Device Evaluation, said the agency is still working its way through more than 600 public comments on its June 2011 “Applying Human Factors and Usability Engineering to Optimize Medical Device Design” draft guidance. (See Also see "Regulatory News In Brief" - Medtech Insight, 27 June, 2011..) FDA hopes to finalize the document by the end of this year, she said.

Human factors and usability engineering focus on making medical devices easier to use so that there are fewer use errors, patient injuries and product recalls. When finalized, the document will replace a July 2000 guidance.

“The only major change I would anticipate between the draft document and the final document is that we will be much more specific about the scope,” says CDRH’s Molly Follette Story.

“As you can imagine, it’s very time consuming. Some of the comments are very simple; others are requiring major conversations within the agency about how we’re going to handle this,” Story said March 21 at the FDA/Association for the Advancement of Medical Instrumentation International Conference on Medical Devices Standards and Regulation in Herndon, Va.

“The only major change I would anticipate between the draft document and the final document is that we will be much more specific about the scope of the document: what it applies to, what types of devices need human factors data and the criteria for us to determine when we want human factors data,” she said.

Overall, she said, written comments were supportive of the draft guidance.

“The human factors people [in industry] are telling us that it is great support for what they know they need to do, and it explains why they need to do it, how they need to do it. They found it to be very useful for their own purposes, which is great. We are supporting them to do what we need them to do," Story said. "I think they’re trying to help us make it better.”

ODE Human Factors Strategy

CDRH is developing an overall strategy for when and how human factors data will be used in the pre-market review process. Story said that Christy Foreman, acting director of the Office of Device Evaluation, asked the human factors team to meet with all the divisions within ODE "to figure out when we're going to get involved and when we're not going to get involved."

FDA currently looks at human factors data only in submissions that are high risk, such as life sustaining and life supporting devices, Story said. Combination products that involve drug delivery tend to be on that list, she noted.

Infusion pumps, in particular, have for many years been prone to usability problems and recalls. To address the issue, FDA in 2010 launched an infusion pump improvement initiative and issued a related guidance document requiring pump makers to submit safety assurance cases for their products. (See Also see "FDA To Impose New Pre-market Requirements On Infusion Pump Makers" - Medtech Insight, 3 May, 2010..)

“But we are beginning to look at other device types,” Story said. “I’m glad to say that FDA is paying more attention to human factors and will be doing so more in the future.”

Firms that are unsure of FDA's human factors data expectations should contact the agency early in the pre-market process, Story said. She said that FDA will often respond to pre-submission related questions or requests within 60 days.

“We are happy to review human factors usability validation protocols. Before implementation is highly recommended so we can get those methods right before you go through a study,” she said.

HFES-AAMI Website

FDA staffer Story referred to a new website – http://www.medicaldevicehumanfactors.org – jointly created by the Human Factors and Ergonomics Society and the Association for the Advancement of Medical Instrumentation at the urging of FDA. It includes:

Links to resources related to human factors, including FDA documents, ISO standards and AAMI standards, as well as several related articles and books
A directory of human factors consultants, including contact information
Information about the Human Factors and Ergonomics Society, and the Association for the Advancement of Medical Instrumentation
Upcoming events related to human factors

Current Scope

The scope section of the draft guidance says that if a manufacturer discovers during device risk analysis that there is moderate to high risk of user error, or if a firm is modifying a marketed device due to problems associated with use, particularly as a corrective and preventative action, the firm should conduct appropriate human factors testing as spelled out in the guidance.

In addition, FDA may request human factors testing for devices subject to special controls or device-type-specific guidance documents. FDA may also request human factors data if it is the least burdensome way to address agency concerns regarding human factors.

Under these circumstances, the draft says, manufacturers would have to submit a report on human factors processes, evaluations and results of validation testing as part of their PMA or 510(k) submissions.

With device interface modifications, Story said, the center believes in taking a risk-based approach to usability data requirements.

“Everything we do for human factors comes to risk profile,” she said. “If the interface has been changed in a way that might have a significant impact on human factors, you might need to do a new study. It depends on the risk of the device in general, but particularly the human factors issues.”

FDA's human factors policy on device modifications is a key concern of AdvaMed's. In comments, the trade group said the draft reads as if it was written for completely new products, even though "the great majority of medical devices are modifications of already cleared medical devices." The group requested more guidance "on adequately determining usability for changed or modified devices."

Human Factors Data Expectations

The draft guidance says that firms should consider device users, device use environments and device user interfaces when they design new products. It recommends that firms use both analytical approaches and formative evaluations for identifying, evaluating and understanding use-related hazards.

Analytical approaches involve "description and systematic decomposition and analysis of device use," the draft says. It requires the identification of known use errors that have occurred in the past with similar devices that could be addressed in the development of the new device. The analytical approach also involves function and task analysis, where the firm breaks down the process of using the device into discrete steps to further analyze potential user error.

Formative evaluations involve studies of how the device is used by end users and can identify problems not understood through the analytical methods. One type of formative study, the cognitive walk-through, involves having an evaluator guide a user or small group through the process of using the device and noting any difficulties the user encounters. Another type, simulated use testing or usability testing, involves observing people using the device in realistic situations.

The guidance provides recommendations for mitigation and control of use-related hazards, as well as design verification testing.

An appendix describes in detail the type of information manufacturers should submit in their human factors engineering (HFE) report to FDA. AdvaMed was highly supportive of this part of the draft guidance, saying in its comments, “We really like the content suggested for the summary HFE report. This is a very helpful guidance to summarize HFE activities for regulatory submission.”

FDA To Clarify Scope Of Devices Covered By Human Factors Guidance

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