Conducting HFE Activities to Meet Global Human Factors Engineering Requirements

By Charlotte Wickham

As discussed during our team’s webinar on Global HFE requirements and subsequent webinar debrief, Human Factors Engineering (HFE) requirements for medical devices vary across different countries and regions. As a result, medical device manufacturers face the challenge of meeting multiple sets of requirements to market their products in different countries. Given that meeting the requirements of one set of guidance alone can often be an involved process, it might seem difficult to meet multiple sets of regulations in a cost-and-time-efficient manner. In this article, we will share some guidance on meeting global HFE requirements efficiently.  

Apply HFE early and throughout the design process. While different regulators across the globe have different HFE expectations, the requirements are all based on the same core HFE principles and underlying HFE processes. As such, starting your HFE work early in device development allows you to develop a comprehensive base which can then serve as building blocks for the location-specific HFE requirements, as the following examples will illustrate.  

Let’s consider the FDA’s HFE guidance and IEC-62366, the usability engineering standard upheld by European regulators. FDA’s CDER (FDA’s center responsible for drug-led combination products) requires that an HF validation test evaluate any tasks with the potential to cause harm. IEC-62366, however, suggests that an HF validation test can focus on the evaluation of tasks with the potential to cause serious harm (i.e., the definition of critical tasks – the tasks in scope of an HF validation test – is different). Consider a situation where your company decided to market your combo product in Europe. Accordingly, you have followed IEC-62366, and planned an HF validation that only evaluates tasks associated with serious harm. Then, the marketing strategy for the combo product changes, and your company now wishes to also market the combo product in the USA. If you have previously performed a thorough use-related risk analysis (including preparatory activities such as a task analysis and known problems analysis), you can use this to determine efficiently which additional tasks will be considered a critical task per FDA’s definition and thus in scope for the HF validation test. If your use-related risk analysis is incomplete or only adheres to a particular set of requirements (e.g., IEC-62366’s HF validation scope), you will not be able to adapt your existing HFE work which as much flexibility and pursue new markets with as much efficiency.  

Moreover, if you conduct HFE activities throughout the design process, you can gather a more complete “base” of knowledge and analysis regarding the usability and risk profile of your device. Such a base enables more flexibility when it comes to meeting HF requirements globally. Not only does it reduce the likelihood of having “gaps” in your documentation at the time of submission, the different HFE processes complement each other, and gaps are therefore easier to spot and address early on.  

Document HFE activities and outcomes. This will save you time when it comes to submitting your product for approval. If you apply HFE early and throughout the design process, and document it accurately and completely as you go, you will have a much easier time putting together your HFE report/Usability Engineering (UE) File, because the inputs will be readily available.  

Understand your different users and use environments. Intended user profiles and intended use environment profiles are documents required by all major HFE standards and guidance documents (e.g., IEC-62366 and FDA’s and MHRA’s guidance documents). Additionally, understanding how your users and use environments differ across your different intended markets is an important step if you are looking to go to market in multiple countries. The characteristics that will affect device performance (aptly named “performance shaping characteristics”) include professional practices, experience with other devices, and cultural factors. These will differ across different countries. Thoroughly understanding the intended users and use environments in your chosen market will allow you to:  

1. Foresee use errors based on cultural factors and clinical practice (e.g., in the UK, it is not standard practice to use an alcohol wipe before a subcutaneous injection, and most participants – including healthcare professionals – will not do it).  

2. Correctly define the participant groups for your summative/HF validation test (e.g., in the UK, Gastroenterology nurses are often responsible for performing endoscopies, whereas in the US, they mostly assist physicians, and this difference might affect the participants you include and the tasks you ask them to perform). 

Determine if you can conduct reduced-scope studies. Some countries have requirements to collect local HF validation test data (e.g., the USA, China), whereas for other countries you might be able to (partially) leverage HF validation test data collected elsewhere (e.g., Canada, Australia). When validating your device, you can consider choosing a country with a local requirement for your full-scope summative test, which (subject to regulators) might include up to 15 participants per user group and include the evaluation of all critical tasks. For countries without a local requirement, you could justify leveraging the data collected elsewhere by demonstrating equivalency in use cases, users, and use environments (as per the previous section). If justifying equivalence is difficult, consider supplementing the existing data with local data collected during a reduced-scope test (e.g., subset of user groups, fewer participants per user group, subset of use scenarios). This enables you to evaluate the safety and effectiveness of your product with all your intended users without the time and cost associated with a full-scope HF validation test in each location.  

If there is a gap between market submissions, leverage post-market surveillance (PMS) data. If you have a product on the market in one country and are looking to submit it for approval in another, this gives you the opportunity to use PMS data from your marketed product within your next HFE submission. Leveraging PMS data for HFE enables you to address the shortcomings of pre-market usability data, where findings are often not based on actual use. For example, imagine that you are developing the residual risk analysis for your next submission. Following the HF validation test, you determined that some of the serious use errors observed were due to test artifacts. You can supplement this assertion by providing PMS data which demonstrates this use error has not been identified with devices currently on the market. More generally, you can use your PMS data to demonstrate how the device is currently performing and justify that use-related risks are being effectively managed by mitigations.  

While the variability of global HFE requirements might seem daunting, they share many underlying HFE principles, and there are steps you can take to maximize the value and global reach of your HFE work. Contact our international team to learn more about conducting HFE work around the globe. 

Charlotte Wickham is Senior Human Factors Specialist at Emergo by UL's Human Factors Research & Design division.