Assessment of adherence to, and persistence with, an electromechanical autoinjector for subcutaneous interferon beta-1a injections for multiple sclerosis treatment over 3 years.

Background: Self-administration of subcutaneous interferon beta-1a (sc IFN β-1a) can be achieved with the RebiSmart® electromechanical autoinjector. This study investigated adherence to, and duration of persistence with, the newest version of the device (v1.6) among 2644 people receiving sc IFN β-1a for multiple sclerosis (MS).

Research design and methods: This retrospective, observational study utilized data from RebiSmart® devices, recorded on the MSdialog database, between January 2014 and November 2019. Adherence and persistence were evaluated over a 3-year period and assessed in relation to age, sex, injection type, and injection depth.

Results: The population of RebiSmart® users (N = 2644) comprised of 1826 (69.1%) females and mean age was 39 (range 16-83) years. Adherence to RebiSmart® use and data transfer to the MSdialog database was consistently high (mean 91.7%; range 86.8-92.6%), including across all variables (81.6-100%). Mean (±SD) persistence during the study period was 1.35 ± 1.06 years, with a maximum recorded persistence of 5.1 years. In multivariate analysis, the longest durations of persistence were observed among older individuals and males (p < 0.0001 and p = 0.0078, respectively).

Conclusions: People living with MS were highly adherent to use of the RebiSmart® device, with higher persistence generally observed for older and/or male individuals.