Real-World Outpatient Resource Use of Patients with Multiple Sclerosis Newly Initiating Subcutaneous Interferon ß-1a vs Oral Disease-Modifying Drugs
Objectives: To evaluate resource use associated with outpatient management of patients with multiple sclerosis (MS) newly initiating subcutaneous interferon β-1a (scIFNβ1a) vs oral disease-modifying drugs (DMDs; ie, teriflunomide, fingolimod, dimethyl fumarate) using real-world data.
Methods: Patients from the IMS LifeLink PharMetrics Plus™ Database between 1/1/2012 and 6/30/2013 met the inclusion criteria: MS diagnosis (ICD-9-CM:340.xx); initiation of scIFNβ1a, teriflunomide, fingolimod, or dimethyl fumarate (1st claim=index date); continuous eligibility 12 months pre- and post-index; no DMD 12 months pre-index (treatment-naïve); and age 18–63 years. Resource use associated with outpatient management was assessed 12 months following DMD initiation and included outpatient visits, neurologist visits, magnetic resonance imaging (MRI), liver function tests (LFTs), and complete blood counts (CBCs). Generalized linear models with gamma distribution and log link assessed resource use controlling for age, sex, region, and clinically meaningful disease severity measures (ie, 90-day pre-index indicators for relapse, neurologist visits, and MRI).
Results: 1665 patients (686 scIFNβ1a, 118 teriflunomide, 455 fingolimod, and 406 dimethyl fumarate) met inclusion criteria (mean age=44.4 years; 75.5% female). After adjustment for demographic and 90-day pre-index indicators, the estimated mean number of outpatient visits per patient was lowest for scIFNβ1a (18.2) vs fingolimod (21.1; p=0.002), dimethyl fumarate (21.5; p=0.001), and teriflunomide (22.9; p=0.003). On average, patients receiving scIFNβ1a had fewer MS-related outpatient visits (6.6) vs dimethyl fumarate (8.7; p<0.001), fewer neurologist visits (5.3) vs fingolimod (6.2; p=0.010), and fewer MRIs (0.54) vs fingolimod (0.72; p=0.018) and dimethyl fumarate (0.77; p=0.007). The mean number of LFTs was lower for dimethyl fumarate (0.45) vs scIFNβ1a (0.63; p=0.037) and higher for teriflunomide (1.16; p=0.010 vs scIFNβ1a). The mean number of CBCs did not differ among DMDs.
Conclusions: In this real-world population, after controlling for demographics and pre-index clinically meaningful indicators of disease severity, several resource use measures associated with outpatient management were lower in patients initiating scIFNβ1a compared with patients initiating oral DMDs.