(52) Impact of Medication Adherence on Clinical and Economic Outcomes in Multiple Sclerosis: A Scoping Review of Real-World Evidence

Background: : Adherence to disease-modifying therapies (DMTs) is essential for improving outcomes in multiple sclerosis (MS), a chronic immune-mediated neurological condition. Although adherence is widely recognized as important, a synthesis of its measurable real-world impact in MS with regard to relapse rates, disability progression, and healthcare resource utilization, is limited. This scoping review summarizes the current landscape of real-world studies evaluating the association between adherence to DMTs and clinical and economic outcomes in MS.

Objective: : To evaluate the impact of adherence to MS therapies on outcomes and costs using real-world data within a broader scoping review.

Methods: : We conducted a scoping review of studies that evaluated medication adherence or persistence using real-world secondary data such as administrative claims or electronic medical records. Full text articles were identified from PubMed, EMBASE, and Web of Science using the terms compliance, adherence, administrative claims, real-world, and observational. Among 1,505 articles initially retrieved, 596 met the inclusion criteria. We identified 8 studies in MS that examined adherence to DMTs and reported outcomes including relapse rates, hospitalizations, healthcare costs, and work productivity.

Results: : Across multiple datasets, adherence to DMTs in MS was consistently associated with better outcomes. Patients with high adherence, defined as medication possession ratio (MPR) or proportion of days covered ≥80%, had lower relapse rates, fewer hospitalizations, and reduced healthcare costs. For example, U.S. patients adherent to DMTs had 29% fewer relapses, 37% lower hospitalization risk, and reduced MS-related costs ($3,380 versus $4,348) compared to non-adherent individuals. Persistence to fingolimod and natalizumab was associated with sustained relapse reductions and cost savings. A 10% increase in MPR, was estimated to reduce emergency visits and inpatient stays by up to 19%, and to lower work loss and indirect costs by 3% to 8%.

Conclusions: : Adherence and persistence to DMTs in MS are consistently associated with improved clinical outcomes and lower healthcare and societal costs, with several studies demonstrating statistically significant benefits. These findings reinforce the importance of adherence-focused interventions and provide valuable real-world evidence to inform payers, providers, and policymakers.

Sponsorship:: This study was supported by the AMCP Research Institute