Annual Cost Burden by Level of Relapse Severity in Patients with Multiple Sclerosis

INTRODUCTION: The severity of relapses varies in multiple sclerosis (MS) and may lead to a differential cost burden. This study aimed to characterize the direct healthcare costs associated with relapses in patients with MS by the level of relapse severity. METHODS: This retrospective analysis used claims data extracted from the MarketScan(®) Databases from January 1, 2013 to March 31, 2017 (study period January 1, 2012 to March 31, 2018). Adult patients with at least one diagnosis of MS and 12 months of continuous enrollment prior to the first MS diagnosis to 12 months after the index date were included. On the basis of the severity of the relapse, patients were stratified into three cohorts: severe relapse (SR), mild/moderate relapse (MMR), and no relapse (NR). All-cause and MS-related costs were analyzed during the 12-month follow-up period. Group differences were assessed using descriptive and multivariate statistical analyses. RESULTS: In total, 8775 patients with MS were analyzed: 6341 (72%) in the NR cohort, 1929 (22%) in the MMR cohort, and 505 (6%) in the SR cohort. Overall, patients were mostly female (76%), mean age was 50 years, and 25% were on a disease-modifying therapy. Mean (standard deviation [SD]) all-cause and MS-related costs among patients with a relapse were higher vs patients without a relapse (all-cause $66,489 [$56,264] vs $41,494 [$48,417]; MS-related $48,700 [$43,364] vs $24,730 [$33,821]). Among patients with a relapse, the mean (SD) all-cause costs were $87,979 [$65,991] vs $60,863 [$51,998] and MS-related costs were $69,586 ($51,187) vs $43,233 [$39,292] for patients in the SR vs MMR cohorts, respectively. A similar trend for increase in cost by relapse severity was observed in the adjusted analysis. CONCLUSION: Total annual all-cause and MS-related costs increased with severity of the relapses. High-efficacy treatments might reduce the severity of the relapses, thereby reducing the cost of care in patients with MS.