RESUMEN
BACKGROUND: Both interferon beta-1b (IFN-ß-1b) and interferon beta-1a (IFN-ß-1a) are immunomodulators that require regular subcutaneous self-administration by patients with multiple sclerosis (MS). However, no electronic autoinjector is available for IFN-ß-1a in the US. OBJECTIVE: This retrospective cohort study investigated adherence to two subcutaneous disease-modifying therapies, IFN-ß-1b and IFN-ß-1a, during two periods (before and after the introduction of the BETACONNECT® autoinjector for IFN-ß-1b). PATIENTS AND METHODS: Data were evaluated from the MarketScan database for adults in the US with an MS diagnosis and a medical claim for subcutaneous IFN-ß-1b or IFN-ß-1a, either before (October 2013-September 2015) or after the introduction of BETACONNECT (October 2016-September 2018). Patient populations were propensity-score matched by demographic and clinical characteristics. Persistence was recorded, and adherence was evaluated by medication possession ratio (MPR). RESULTS: The study included 196 IFN-ß-1b and 365 IFN-ß-1a people with MS (PwMS) (pre-BETACONNECT period), and 126 IFN-ß-1b and 223 IFN-ß-1a PwMS (post-BETACONNECT period). In the pre-BETACONNECT period, the proportion with at least 80% MPR was higher for IFN-ß-1a (90%) than for IFN-ß-1b (83%), but in the post-BETACONNECT period the proportion with ≥ 80% MPR was higher for IFN-ß-1b (92%) than for IFN-ß-1a (86%). In the pre-BETACONNECT period, median persistence (in days) was higher for IFN-ß-1a (199) than for IFN-ß-1b (152), while in post-BETACONNECT period persistence was higher for IFN-ß-1b (327) than for IFN-ß-1a (229). CONCLUSIONS: Following the introduction of BETACONNECT, this exploratory study suggested that PwMS taking IFN-ß-1b were more adherent compared with those taking IFN-ß-1a, with higher persistence, and more than 90% reached 80% MPR, a threshold commonly used to define good adherence.