OBJECTIVES : This retrospective analysis of a US claims database evaluated adherence, as indexed by medication possession ration (MPR) and persistence, to two subcutaneous disease-modifying therapies (DMTs) for multiple sclerosis (MS); interferon beta (IFNβ)-1a and IFNβ-1b, during the period prior to and following the introduction of an electronic autoinjector device (eAID) for IFNB-1b.

METHODS : Data from MarketScan for patients with a medical claim for IFNβ-1a or -1b either prior to the introduction of the eAID (Oct 2013–Sep 2015) or post approval and uptake of the eAID (Oct 2016–Sep 2018), were evaluated. Patients aged ≥18 years with ≥1 confirmed MS diagnosis in the 12-month period prior to the first prescription of relevant DMT within the defined time periods were included in this analysis. Four cohorts were defined, consisting of incident IFNβ-1a or -1b users over the 24-month periods prior to and following the introduction and uptake of the eAID. Within each time period, patient populations were propensity-score matched on demographic and clinical characteristics. MPR and persistence to IFNβ-1a and -1b are described for the period prior to and following the introduction of the eAID.

RESULTS : MPR: In the pre-eAID period, >80% of IFNβ-1a users met an 80% threshold, while almost 30% of IFNβ-1b users did not. In the post-eAID period, >80% of both IFNβ-1a and -1b users met an 80% threshold.

Persistence: In the pre-eAID period, median persistence in days was higher for IFNβ-1a (199, 95%CI 167 – 235) than for IFNβ-1b (152, 95%CI 105 – 231) while in post-eAID period, persistence was higher for IFNβ-1b (327, 95%CI 244 – 440) than for IFNβ-1a (229, 95% CI 184 – 304).

CONCLUSIONS : Following the introduction of an eAID, users of IFNβ-1b were more adherent, with improved persistence and with >80% of users meeting 80% MPR, a threshold commonly used to define good adherence.