Human Factors and Packaging: Adventures in Medical Device Usability

By Stephen B. Wilcox, PhD, FIDSA

There have always been human factors issues associated with medical packaging, particularly packaging designed for use by patients, as opposed to medical professionals. For example, packaging designers have struggled for years with making packaging easy to use for target users while still making it childproof. The catch, of course, is that target users may suffer from disabilities like compromised dexterity or vision problems, or even cognitive deficits, by virtue of the very conditions—such as diabetes, glaucoma, and heart failure—that their medical devices or drugs are designed to address.

Stephen B. Wilcox, Ph.D., FIDSA

Thus, the challenge is how to make a package easy to open for a person with a variety of disabilities, but difficult—or, better, impossible—to open for a child. One approach is to take advantage of the relatively larger hand of the adult rather than assuming more strength or a better ability to follow the proper procedure to get a package open. In other words, the idea is to design a packaging-opening procedure that requires a hand of a certain span.

In fact, making packaging usable involves the same methods required for making devices usable:

  • Acquiring a good understanding of real-world users, use conditions, and procedures
  • Applying technical information about the users, such as strength, expectations, and body sizes
  • Performing cyclical testing of prototypes to empirically “work out the bugs” prior to finalization

These methods are collectively referred to as the “usability engineering process.”

One thing that’s changed recently, though, is human factors-related regulatory requirements, particularly those specific to drug packaging. For devices, perhaps the best way to think of the regulatory requirements for packaging is to consult IEC/ISO 62366:2007, “Application of Usability Engineering to Medical Devices.” In reference to “information for safety,” the standard states: “If information for safety is used as a risk control measure, the manufacturer shall subject this information to the usability engineering process (Section 4.1.3).”

Packaging may contain “information for safety,” specifically. But, regardless, the same principle applies to packaging that applies to information for safety: If packaging is used as part of the methods for achieving safety, then human factors methods are required.

In general, packaging must be subjected to the usability engineering process, which is described in the FDA draft guidance on human factors issued by CDRH, “Applying Human Factors and Usability Engineering to Optimize Medical Device Design,” if the packaging has any safety implications. That is, the usability engineering process must be applied if the packaging is required for safety or if flaws in the packaging can cause a safety, or even an effectiveness, problem. Needless to say, effectiveness is affected, and, possibly, safety as well when the intended user cannot open packaging in the first place.

The recent change, though, isn’t with device packaging, but with drug packaging. FDA’s Center for Drug Evaluation and Research (CDER) has issued two draft guidances within the past year and a half that, in effect, bring drug labeling and packaging into the human factors orbit in the way that devices have been for several years.

“Safety Considerations for Product Design to Minimize Medication Errors” was released in December 2012, while “Safety Considerations for Container Labels and Carton Labeling Design to Minimize Medication Errors” followed in April 2013.

The 2012 draft guidance provides a blueprint for building in safety—i.e. addressing use error—with drug products:

  1. Consider a series of issues regarding end-users (“What critical tasks must users perform?”) and environments of use (“Is this product atypical for use within this environment?”)
  2. Proactive risk assessments

In the discussion of proactive risk assessments, the guidance provides a series of specific principles to follow for various drugs and suggests two basic methods—failure modes and effects analysis (FMEA) and simulated use testing. The latter represents the usability testing mandated in the aforementioned CDRH draft guidance regarding human factors, to which the CDER Guidance refers. Also, in its discussion of FMEA, the guidance makes reference to ISO 14971:2007. The 2013 guidance discusses risk assessment as well, but it also provides a set of specific rules for labeling.

In sum, just about anything human factors-related that can be said of any other product that humans use can be said of packaging: It needs to be physically usable, it should minimize use errors, the text must be readable and understandable, etc. Thus, basic methods that have been applied for years to human interfaces of all kinds, also apply to medical packaging.

What’s different, though, is that packaging, for both medical devices and drugs is now subject to a series of regulatory requirements that mandate good human factors practices—at least as they relate to safety and effectiveness. In other words, applying human factors principles and methods to medical packaging has always made good sense. Now, it’s also a regulatory requirement. 

Stephen B. Wilcox, is a principal and the founder of Design Science (Philadelphia), a firm that specializes in optimizing the human interface of products—particularly medical devices. 

Interested in medical packaging design? Download the white paper, "Critical Considerations When Designing Medical Packaging."

 

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