You can integrate human factors engineering (HFE) research into clinical trials to assess whether patients can use your device safely and effectively. This article describes key considerations when preparing, collecting and analysing HFE data collected during a clinical trial with the goal of improving commercial device design.
Human factors engineering (HFE) is crucial in developing an effective device and is critical to meeting global regulatory expectations. HFE is a multidisciplinary field involving engineering, psychology and design, and it focuses on ensuring that a device’s design is well-matched to its intended users. Specifically, drug–device combination products should be safe, usable and satisfying while accounting for intended users’ skills, knowledge, abilities and limitations.
HFE activities can occur throughout the device development process, with the ultimate end goal of demonstrating that intended users can use the device safely and effectively. At the same time, clinical trials play a well-known and crucial part in the drug development process, where each trial exposes the drug’s potential efficacy. Clinical trials require such a significant time and monetary investment that you might wonder whether there is an opportunity to integrate HFE data collection within clinical trials.
A clinical trial provides an excellent opportunity to collect HFE data, such that you can gain valuable insights about the device’s use alongside data about the drug’s efficacy. Sample HFE-oriented research questions that you can embed in clinical trials include: will intended users know the proper injection angle for injecting the drug within your prefilled syringe such that the drug is injected into the proper tissue? Will the intended user know the appropriate way to disinfect their nebulizer to avoid infection? Can intended users understand how to properly reconstitute the drug so they receive the intended benefit?
This article explores how HFE activities can play a critical role throughout the drug-device development process — particularly during clinical trials — by describing how to prepare for HFE activities and collect and analyse HFE data.
While HFE research is often a standalone activity, collecting HFE data during a clinical trial can prove advantageous. Because intended users of a device are already participating in the clinical trial, collecting HFE data alongside clinical trial data allows you to maximise participant engagement and your monetary investment. When collecting HFE data during clinical trials, consider the following key points during preparation to optimise the quality of data and, ultimately, the positive impact on your device.
The data collection method for your clinical trial will impact the methods for collecting HFE data. For example, if the clinical trial participants are undergoing treatment at a clinical trial site, as is traditionally the case, you could observe and interview the involved users, including healthcare professionals (HCPs) or lay people in the case of supervised selfadministration, regarding their experience preparing and administering the drug. However, if the clinical trial is fully or partially decentralised, participants might administer medication at home. In that case, it would not be practical to observe them directly, and you would need to use other data collection methods, such as remote interviews or questionnaires.
Within the HFE field, a wide array of data collection methods are aimed at refining a device’s design and labelling, including contextual inquiry, individual and group interviews, surveys, expert reviews and usability tests. Certain HFE data collection methods are more or less suitable based on the clinical trial approach. Direct observation of device use is often the most powerful method because you observe interactions firsthand rather than relying on self-reported experiences. Observations are often paired with interviews to gather participants’ perspectives and maximise he value of the exercise, but interviews about device interactions could also be used as a stand-alone activity if direct observations are not practical. While surveys typically do not yield data with as much richness or depth as interviews and observations, they can still be a valuable tool to rapidly collect participants’ perceptions of using a device from relatively large sample sizes. Manufacturers can also pair their clinical trials with a diary study, a form of survey in which participants record their responses to questions or prompts over multiple days or weeks to gain in-depth data over a sustained period.
You can use the aforementioned data collection methods individually, but combining different approaches within a clinical trial provides the opportunity to dig deeper into the data. For example, combining a diary study with telephone or in-person interviews enables you to follow up on data collected in the diary study to gain a greater understanding of the intended users’ needs and preferences. Furthermore, consider implementing multiple rounds of HFE research at different clinical research stages and throughout your device’s development process to work toward the strongest possible design.
The stage of device development often influences the goal of HFE research, considering the device itself as well as instructional materials, packaging and training.
If the manufacturer has more flexibility to refine the device design earlier in the device development process, they can appropriately scope HFE research to collect and analyse feedback on the device itself. For example, observations and interviews regarding the use of a pen injector might reveal that participants struggled to read the dose counter when dialling up a dose because the numbers were too small. Consequently, the manufacturer could opt to increase the size of the numerals on the dose counter.
Later in the development process, manufacturers tend to be more limited in their flexibility for design refinements. HFE research might focus on improving the instructions for use or device labelling in such a case. For example, interviews might reveal that participants found the steps related to priming a syringe confusing. To improve clarity, the manufacturer could refine the text and enhance the images for those steps.
The data yielded from HFE research described thus far would be considered “formative” in that they are data collected during the device’s development. Contrasting this is an HF validation test. From an HFE perspective, manufacturers must conduct an HF validation test for any medical device posing potential harm to users to validate that the intended users can safely use the device design in the intended use environments. HF validation tests require a high level of rigour and control related to participant user groups and the test environment. Because of this, formative data lends itself to collection alongside a clinical trial. However, manufacturers can focus formative data collection on interactions that could lead to harm — which are typically the focus of an HF validation test — with the goal of improving the overall safety of the device for any subsequent HF validation testing.
Though the scope of formative research is up to manufacturers, a common practice for formative usability testing (including observations and interviews) is that five to eight participants per type of user (e.g., patient, HCP) will yield the majority of potential interaction challenges. If the research involves only interviews and no observations, consider skewing higher (e.g., eight to 10, depending on the user group’s homogeneity) than this recommendation, as you likely will not uncover as many interaction challenges. Along those lines, a survey could include even more participants, noting the data is not as rich and the time associated with distributing a survey to a larger group is minimal.
Researchers should prepare for data collection after planning the HFE research parameters. Below are some key points to keep in mind when collecting data. Notably, each point requires significant skill and practice to get the most out of your HFE activities. When staffing HFE research projects, consider the experience researchers bring to bear to help ensure that you collect meaningful and relevant data.
While there is no specific requirement for who can collect HFE data, choose someone who has a deep enough understanding of the device, the research goals and at least a minimal level of training on how to best collect HFE data to yield robust and unbiased results. This person could be a representative from the manufacturer, particularly if the study takes place at a clinical site, or they could be an HCP overseeing patient self-administration. Manufacturers with limited internal resources to support HFE research can also choose to engage HFE consultants to leverage the consultant’s expertise.
The most important thing to keep in mind when conducting an observation of device use is to be a neutral observer. The observer likely has a deep knowledge of the device but should avoid intervening and keep a neutral demeanour. Encourage the participant to think independently as if they were working on their own. For example, if the participant asks, “What do I do now?,” you can ask, “What do you think you should do?”
When conducting an interview, either as a standalone activity or after observing device use, the moderator’s ultimate goal is to understand what aspects of the interaction participants struggle with and why. If the moderator observes or the participant reports a difficult or incorrect interaction, the moderator should ask questions to understand the root cause of the challenge. When doing this, avoid leading questions, such as “That small needle made the medication difficult to draw up from the vial, right?,” and ask open-ended questions, such as “Why do you think that happened?” or “Is there something about the device or the instructions that led to that mistake?”
Surveys can yield valuable insights if you have limited access to participants during device use. For example, participants could be using the device at home without the presence of an HCP. Begin your survey with an introduction and collection of participants’ background information (e.g., age, injection experience, impairments). Consider digging into the ease or difficulty of each step of device use, perhaps with a numerical rating and an open response for participants to describe the rationale behind their rating. You can also seek more general feedback, such as overall impressions of device use, use safety or instructions.
After you have collected HFE data, it is time to synthesise it into valuable information that you can use to improve your device’s design and, if all goes well, boost your commercial success. With formative data, focus on trends rather than one-offs to uncover design refinements that benefit many rather than tailoring the device design to a single user. Document your findings in a report that could describe, for example, the strengths and opportunities for improvement for the device and instructions. With this information, you can improve the design of the device and/or instructions and, if time allows, conduct further formative research to reveal if the changes are effective or require more refinement.
Notably, depending on the clinical trial participants’ characteristics, HFE data collected alongside the clinical trial might not fully represent all intended users or how the device is used in a natural environment. For example, participants might have more intensive training on the device in the clinical trial than they would in the real world. In such cases, collecting additional HFE data outside of clinical trials is essential to capture the full scope of realistic interaction with the device by your intended users.
Though clinical trials are often a primary focus of drug development, consider conducting HFE research to ensure that people can use your device safely and effectively. Integrating HFE into clinical trials provides an opportunity to collect valuable insights from users, ultimately leading to improved commercial device design. With the proper preparation and data collection techniques, you can successfully combine both activities.