Instructions that come with a medical device are intended to provide “adequate directions for use” such that the device can be used safely and effectively. To meet that goal, instruction documents must have two key components. One is that the content is accurate and includes all of the elements of safe use of that device. The second component is that the information has to be presented in a way that is likely to successfully transmit the information to the users. This is the human factors part of instruction design.
A recent Food and Drug Administration (FDA) communication on duodenoscope reprocessing safety addressed (in part) problems with the instructions. These instructions were already part of FDA-ordered postmarket studies and were referenced in its March 2018 warning letters to the three scope manufacturers. Based on ongoing studies, the FDA concluded that the instructions in current duodenoscope user manuals are difficult for reprocessing staff to comprehend and follow. As a result, some reprocessing staff missed one or more steps in the process and needed additional training to complete the process properly.
One might ask whether the fault here is with the instructions or the users, although “blame-the-user” is not a productive approach to correcting use errors. The FDA concluded that the descriptions of some of the processing steps in the user manuals were unclear, which clearly takes the users off the hook. In fact, Jeff Shuren, director of the FDA’s Center for Devices and Radiological Health, said in a press release that “it has become clear that following the manufacturer’s reprocessing and maintenance instructions, while critical, is not sufficient to avoid all infections associated with the use of duodenoscopes.”
It should be noted here that these instructions had already passed through both the manufacturer’s development process and FDA scrutiny. This example also reminds us that there can be many “users” of a medical device, including clinical staff, reprocessors, healthcare technology management professionals, and patients.
The role of instructions in medical device issues is certainly not unique to duodenoscopes. The FDA recall database has a pull-down menu of root causes that includes “Labeling False and Misleading” and “Label Design.” The database lists a total of 356 recalls under False and Misleading and more than 500 under Label Design. Note that the database cannot return more than 500 entries. You can narrow the date range and use repeated searches to work around this problem.
An example under the “False and Misleading” category is another cleaning case, this time involving a manufacturer that removed a manual cleaning method from its instructions. A different example was the recall of a surgical device that was intended to remain in place and not be removed—but some surgeons were still trying to remove it. This leaves open the question of what happens if a device needs to be removed for cause. Typically, there are no instructions related to dealing with unintended situations, even when they are known to occur.
Let’s examine some “Label Design” recalls. In one case, a service guide was issued that addressed replacement of a battery that is more than three years old or has been through more than 300 cycles. This category also includes a recall of instructions related to cleaning a heater unit. In another example, the instructions for an implant were revised to provide a more precise description of an unlocking procedure, in order to advise surgeons not to fully unscrew the locking screw.
Setting aside the issue of what the instructions say—do users actually read them? The answers range from “no,” to “I don’t know where to find them.” In some cases, users will justify not having read the instructions. In an informal study I conducted in 2014, users reported that they did not read instructions because:
- They were often too long and too complicated
- In-service or peer training obviated the need to read the manual
- A short, possibly locally produced “cheat sheet” replaced having to read the complete instructions for use
- They couldn’t possibly read all the manuals for the numerous devices they work with
Such declarations may be troublesome when there is an adverse event with the use of a device.
Overall, the intent of device instructions is to provide necessary and useful information in a form that can be easily read and understood. Pre-purchase review should include the instructions to see if they meet this goal. Such a review should be done by people other than those who wrote the instructions or who are highly familiar with the device.
Facilities should set expectations that their users will actually read the instructions, and time should be allocated for this purpose. If there is confusion in the instructions, this should be reported to and resolved with the manufacturer. Risk management should ensure that this takes place so that one never hears the answer “No, I never read the instructions.” Finally, supervisory personnel, as part of their oversight responsibilities, should monitor compliance with the instructions.
William Hyman, ScD, is an adjunct professor of biomedical engineering at The Cooper Union and a consultant in New York. He is also a professor emeritus of biomedical engineering at Texas A&M University.