Evolution of the RebiSmart® Electromechanical Autoinjector to Improve Usability in Support of Adherence to Subcutaneous Interferon Beta-1a Therapy for People Living with Multiple Sclerosis.

Background: The RebiSmart® electromechanical autoinjector supports people living with relapsing multiple sclerosis (MS) with their adherence to treatment with subcutaneous interferon beta-1a (sc IFN ß-1a; Rebif®), a well-established and effective therapy. We report on the validation of the next-generation device, RebiSmart 3.0, tailored to meet patients' changing needs. Methods: To conclude a series of formative usability studies, a final formative study of an updated prototype version of the RebiSmart electromechanical autoinjector was conducted to identify the device's strengths, potential device-related use errors, opportunities for improvement, and to inform device safety. The findings were incorporated into the next-generation device, RebiSmart 3.0, which was then evaluated in a summative usability study involving 45 participants. The study consisted of evaluation activities - use scenarios and knowledge tasks - designed to validate mitigations to reduce the risks of not successfully completing critical tasks for successful administration of medication. During each evaluation activity, observations (including use errors, instances of moderator assistance, close calls, and difficulties) were recorded, focusing on the potential for serious harm arising from not completing critical tasks. Participants then provided their subjective assessment of RebiSmart 3.0 as part of a user needs survey that assessed device usability and design. Results: Regarding critical tasks, main findings were failure to inspect/dispose of the cartridge and not washing hands or disinfecting the injection site. These issues could be readily overcome by modifying future training. In the subjective assessment, 43 out of 45 participants considered the updated device safe to use as-is. In the user needs survey, overall, the participants rated the device positively. Conclusion: Findings validate the safety of use of the next-generation device, RebiSmart 3.0, through a comprehensive evaluation of use scenarios and knowledge tasks by the study participants, who provided positive ratings of the device in the user needs survey.