Human factors and usability engineering in the development of SMT-101 for the treatment of pulmonary arterial hypertension

Formative Study on the Wearability and Usability of a Large-Volume Patch Injector

Background

The subcutaneous self-administration of biologics using a single large-volume bolus dose requires novel large-volume patch injectors. However, the usability and wearability of such on-body devices has rarely been investigated thus far. Therefore, this formative simulated use experiment studies the overall handling and acceptability in terms of the size and weight of a novel 10 mL large-volume patch injector device platform.

Methods

Twenty-three participants, including patients and healthcare professionals, simulated two injections with the large-volume patch injector, each lasting 17 min. During the injections, the patient participants performed predefined movements and activities with the on-body devices. Perceived usability and wearability were assessed through observation by the moderator and participant-reported feedback using five-point Likert scales and open-ended interviews.

Results

All participants successfully completed the simulated injections. Only non-serious usability issues were identified. Users rated the device acceptability in terms of wearability and usability with high ratings.

Conclusion

The results suggest the safe and effective usage of a novel prefilled large-volume patch injector that enables the subcutaneous delivery of a single bolus dose of up to 10 mL with an injection duration of 15 min. The participants of the simulated use study successfully used the device regardless of the disease state, age, or body size and habitus.

How to prevent medication errors: a multidimensional scaling study to investigate the distinguishability between self-injection platform device variants

Background: The importance of subcutaneous drug delivery using self-injection devices based on common device platforms continues to grow. The resulting broad adoption of potentially look-alike or similar devices, however, raises concerns over limited device distinguishability and ensuing risk of medication errors. The objective of the study is thus to understand whether and how users effectively distinguish between self-injection device variants. Methods: Seventy-four patients, caregivers, and healthcare professionals were asked to pairwise rate the similarity of eight platform autoinjector variants. Multidimensional scaling was then used to convert individual ratings into spatial configurations and thereby identify the attributes that influence device distinguishability. Results: Five different device attributes driving distinguishability were identified. Three of the attributes corresponded to single design features (the label color, device size and device shape). Two device attributes (the aspect ratio and chromaticity) combined distinct yet interrelated design features. Conclusions: The study provides initial empirical evidence that users are able to distinguish between device variants and as to what device attributes drive distinguishability. Furthermore, the results highlight patterns in how various user groups distinguish between device variants. These patterns relate with the user group characteristics (e.g. age, sight or dexterity) and the context of device usage (e.g. healthcare professionals).