Presentation (CTI)

OBJECTIVES: To assess the feasibility of a claims-based algorithm in identifying events often associated with a relapse (EOAR) occurrences amongst patients with Multiple Sclerosis (MS) on natalizumab therapy within the PearlDiver Mariner Database.
METHODS: The PearlDiver Mariner Database from years 2017 to 2022 was utilized for this analysis. Patient inclusion criteria was based on MS diagnosis with at least two years of continuous natalizumab therapy (with allowance for 60 days gap to account for extended interval dosing) with at least 6 months of baseline continuous data prior to their first claim of natalizumab. The EOAR algorithm was defined as either an inpatient admission with MS as the primary diagnosis code or as an outpatient or emergency room visit for MS and use of high-dose intravenous steroids, high-dose oral steroids (greater than 500mg oral prednisolone equivalent per day), adrenocorticotropic hormone, or total plasma exchange within 30 days after the visit. Any relapse event occurring within 30 days of one another were considered the same relapse event. Annualized relapse rates (ARR) were calculated from the person year method.
RESULTS: A total of 2813 patients were included in the study with an average age of 43 years with the majority of patients female (76.5%) and were treated outpatient. Overall, 24 patients experienced a relapse in the follow up period with a total of 14 relapse occurrences in year 1 and 13 relapse occurrences in year 2. The ARR was 0.50 in year 1 and 0.47 in year 2. The majority of relapses were identified by inpatient stays with MS as the primary diagnosis.
CONCLUSIONS: Overall, the claims-based relapse algorithm may overestimate the occurrence of EOAR events within the PearlDiver Mariner dataset likewise to other claims databases in previous studies. Follow up studies with additional criteria for the inpatient admission criteria would be of interest.