The impact of persistence with therapy on inpatient admissions and emergency room visits in the US among patients with multiple sclerosis

Abstract

Objective:Disease-modifying therapy (DMT) for multiple sclerosis (MS) can reduce relapses and delay progression; however, poor adherence and persistence with DMT can result in sub-optimal outcomes. The associations between DMT adherence and persistence and inpatient admissions and emergency room (ER) visits were investigated.Methods:Patients with MS who initiated a DMT in a US administrative claims database were followed for 1 year. Persistence to initiated DMT was measured as the time from DMT initiation to discontinuation (a gap of >60 days without drug ‘on hand’) or end of 1-year follow-up. Adherence to initiated DMT was measured during the persistent period and was operationalized as the medication possession ratio (MPR). Patients with an MPR <0.80 were considered non-adherent. Claims during the 1-year follow-up period were evaluated for the presence of an all-cause inpatient admission or an ER visit. Adjusted odds ratios (AORs) for inpatient admission or ER visit comparing persistent vs non-persistent and adherent vs non-adherent patients were estimated using logistic regression models adjusted for patient characteristics.Results:The final sample included 16,218 patients. During the 1-year follow-up period, 35.3% of patients discontinued their initiated DMT and 13.9% were not adherent while on therapy. During that same period, 10.0% of patients had an inpatient admission and 24.9% had an ER visit. The likelihoods of inpatient admission and ER visit were significantly decreased in persistent patients (AOR [95% CI] = 0.50 [0.45, 0.56] and 0.65 [0.60, 0.69], respectively) and in adherent patients (AOR [95% CI] = 0.83 [0.71, 0.97] and 0.86 [0.77, 0.95], respectively).Conclusions:Persistence and adherence with initiated DMT are associated with decreased likelihoods of inpatient admission or ER visit, which may translate to improved clinical outcomes.