FDA Guidance on Medical Devices for Home Use

By William A. Hyman, ScD

Home use of medical devices includes both prescription and over-the-counter products. Among prescription devices, some may be intended by the manufacturer to be used at home, and others may not have that intent but are provided nonetheless to patients by or through prescribers. All home use devices raise basic questions:

• Is the design of the device such that the intended patient population and/or their caregivers can expect the device will be used safely and appropriately?
• Do the contents of the instructions for use (IFU)—if read—provide appropriate directions including necessary warnings and cautions?
• Is the design of the IFU such that it is likely to be read and understood by the user population?
• Are the content and design of the label appropriate to attract and enable reading?
• Where applicable, has the prescribing or recommending professional provided adequate patient-specific instructions?
• Is follow-up with the provider necessary to see if the device is being safely and effectively used?

A recent FDA Guidance Document (GD) dated August 5, 2014, addresses some of these issues. GDs are FDA’s effort to explain its “current thinking” about regulatory issues, without in principle actually creating new regulations that would require formal rule making. This GD is addressed to manufacturers in order to assist them in their design process and to show them what issues the FDA may address in any FDA review of the device before it is marketed. The degree of scrutiny in such reviews depends on device classification. In most cases Class I devices receive no review, Class II devices receive a moderate (and sometimes controversially light) degree of review under the “510(k)” process, and Class III devices receive extensive review under the premarket approval process.

In addition to informing manufacturers what the FDA is thinking, a GD also informs other FDA staff what the FDA has said it is thinking. Thus review staff might use a GD to see if the manufacturer has followed FDA’s advice, even though compliance with the GD is not officially mandatory.

Elements of the Guidance Document

This GD addresses a number of elements of safe use at home including sections on the environment of use, consideration of the intended and likely users who for the most part are not medical professionals, general design considerations as they might apply in particular to home use devices, human factors (although human factors considerations apply throughout the above), and post-market considerations.

Environment

Environment of use considerations addressed include location, potential contaminants, utilities, temperature and humidity, airflow, travel-related issues, fluid ingress, and storage. In all of these regards it should be remembered that there is a wide range of at-home situations across our population and that assumed normative conditions with which designers and healthcare professionals are familiar may not apply to all potential users.

Aside from travel, the GD does not address the multitude of things a user might be doing at home or elsewhere (e.g. shopping, fishing, playing) while also wearing or carrying their home-use medical device. The problems that this might create depend on the acuity of the patient and the nature of the device.

User

User considerations address the personal characteristics of the user and/or caregiver population. These characteristics include strength, mobility, cognitive and sensory functionality, general education and language skills, and emotional attributes that may influence safe and effective use. A classic example in this regard is that people with diabetes may also be frail, have limited manual dexterity, and have reduced vision. Thus a device that is mechanically difficult to use and has components or labels with small font may present challenges to the intended population. Similarly, bed-rail entrapment may be a particular risk to mobility or cognitively impaired individuals, yet these are the very people for which bed rails are generally used. Since this GD addresses FDA regulations it should be noted that bed rails and other assist devices are examples of products that might be purchased in the consumer market and which have seen no FDA scrutiny including even registration with the FDA.

Design

The FDA has previously promulgated Design Control requirements that apply to medical devices. In the GD, general aspects of Design Controls are mentioned, including establishing user needs and using a risk management plan. For the latter the GD says that manufacturers “should consider” developing a risk management plan, and one that includes in particular home users. Yet the words “should consider” might suggest that doing so is optional.

One of the specific design areas mentioned, without explanation as to why this deserves particular attention, is lock-out mechanisms to limit the user’s ability to alter settings. It is stated, also without explanation, that “the safety of home use devices should not depend solely on such mechanisms.” Such a statement might be expected to trigger an FDA challenge when a design that is presented for review has such a feature. 

Other special considerations addressed are maintenance, calibration, mechanical durability, electrical supply variability, electromagnetic interference, wireless components, and alarms. The wireless discussion provides another example of the potential interaction of FDA design advice with FDA review expectations in that the GD says that “the device description in the premarket submission should contain a complete description of the exact wireless technology used…” including the applicable risk management. In other words, having provided this advice, the FDA will explicitly want to see if the manufacturer has followed it, not withstanding that the advice in a GD is officially non-binding. For alarms the FDA “recommends that you provide alarm signals in at least two of the three following modes: visual, auditory, tactile.”

Not mentioned are considerations of the availability of suitable Internet or other data connections for devices that are intended to have external communication capability. Lack of or inadequate service is another example of design assumptions that may be based on our personal life style that possibly may be inapplicable to someone else’s life style.

Human Factors

As in the Design section, the GD reminds us of general human factors considerations and then provides some particular discussion of user training and certification. Here the FDA notes that home users may not understand multiple steps, may receive minimal training or teaching on how to operate their devices, and may not be able to understand multiple warnings and precautions. Although not discussed in the GD, the same issues of reading and understanding instructions can also apply to professional users of medical devices. “Certification” is not described other than with respect to the mention of “recertification.” Certification might imply, however, that some kind of affirmative proof of user understanding and ability should be obtained before the device is deployed in the home. This is an important concept that could also have broad implications for all users of medical devices. Namely, how do users get trained, is that training adequate, and how do we know?

Labeling

The GD reiterates general labeling requirements and notes that reliance on information in the IFU “assumes that the user will remember or refer back to the information.” This skips over the assumption that they read it in the first place, and if so, that they functionally understood it. In the case of rental equipment, the GD also skips discussion of the unfortunate fact that rental suppliers do not always provide the original IFU.

Specific labeling issues addressed include using the device in an emergency, disposal, and hygienic maintenance. The emergency considerations address natural disasters that might interfere with power or supplies. Interestingly, the FDA suggests having the manufacturer’s telephone number handy without considering that telephone service might also be unavailable. There are of course many other “emergencies” that could be considered such as device failure. Disposal includes biohazards, a home use issue that in general receives little attention.

An issue with some home-use devices is that the labels on the device may be in a very small font and awkwardly positioned. One of my favorites in this regard is the label on a patient lift which was wrapped more than half-way around an angled cylindrical tube. Even if the intended reader could manage the tiny font, the label could not be read from any one fixed position but instead required repeated movement of at least the head from one side of the tube to the other and back. This type of label is not one that could be expected to be carefully read and understood.

Post-market Activities

Two issues are addressed for post-market activities. One is the availability of phone, email, or web support. The second is adherence to Medical Device Reporting requirements. The latter is applicable to all medical device manufacturers, so it is not clear if a reminder here is just a simple reiteration of this, or if there is a suggestion that manufacturers of home use devices may, at least in some cases, be out of the mainstream of the medical device industry and therefore need particular instruction in this regard.

Conclusion

It is no doubt correct that the home use of medical devices presents some design and labeling issues that are distinct from similar issues for devices intended for professional users. There has also been much discussion that home use will increase, perhaps particularly enabled by “smart” or at least connected devices. Thus the home use arena does deserve special attention, and this GD could potentially be useful in giving some designers ideas that they might not otherwise have thought of, and/or notice of specific expectations the FDA will have when reviewing their products.

What is unlikely to ever be measured is whether the GD has had (in time) any actual impact on home device safety. This is of course an issue for any proactive intervention when there is no means or intent to assess the effect of the intervention on outcomes. This is often the missing link of a simple three-part test for a safety intervention:

1. What is the problem exactly?

2. How does the intervention address that problem?

3. How will we know that it did?

The FDA, like other regulatory or accreditation agencies, proceeds on the assumption that what they are doing is beneficial. This once led to an email exchange I had with an FDA official I knew on the value of the Quality Systems Regulations. I emailed the somewhat snarky but friendly question: “Do the Quality System Regulations lead to quality systems that lead to quality products?” The answer was: “That’s our position and we are sticking to it.”

William Hyman is professor emeritus of biomedical engineering at Texas A&M University. He now lives in New York, where he is adjunct professor of biomedical engineering at The Cooper Union. Hyman may be contacted at w-hyman@tamu.edu.

Reference

U. S. Food and Drug Administration. (2014, August 5). Design considerations for devices intended for home use: Guidance for industry and Food and Drug Administration staff. Retrieved from http://www.fda.gov/downloads/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/UCM331681.pdf