Reasons for discontinuation of subcutaneous interferon β-1a three times a week among patients with multiple sclerosis: a real-world cohort study

Table 1 Demographic and clinical characteristics of patients with multiple sclerosis initiating subcutaneous interferon β-1a, three times weekly, by discontinuation status

Characteristics	sc IFN β-1a tiw
	Total sample (N = 5956)		Discontinued (N = 2862)
	n	%	n	%
Female sex	4447	74.7	2177	76.1
Age, mean (SD) years	44 (10.7)		44 (10.8)
Region
Northeast	999	16.8	481	16.8
North Central	1764	29.6	766	26.8
South	2156	36.2	1066	37.2
West	968	16.3	517	18.1
Unknown	69	1.2	32	1.1
Charlson comorbidity index
Index = 0	3974	66.7	1887	65.9
Index = 1	1102	18.5	552	19.3
Index = 2	501	8.4	242	8.5
Index ≥ 3	379	6.4	181	6.3
Relapse per year, mean (SD)	0.21 (0.57)		0.25 (0.55)
High relapse (≥2 relapses)^a	271	4.6	154	5.4
DMD use history	2162	36.3	1143	39.9
Treatment duration, median (IQR) months	9 (3–22)		6 (2–15)
Persistence	5634	94.6	2645	92.4
Adherence to treatment <80% (vs. ≥80%)	3078	51.7	2691	94.0
Baseline corticosteroid use	2384	40.0	1194	41.7
Follow-up
NSAID use	3221	54.1	1862	65.1
Antidepressant use	3020	50.7	1682	58.8
Anxiolytic use	1229	20.6	753	26.3
Corticosteroid use	2222	37.3	1362	47.6

DMD disease-modifying drug, NSAID non-steroidal anti-inflammatory drugs, IFN interferon, IQR, interquartile range, SC subcutaneous, SD standard deviation, Tiw three times a week
^aHigh relapse activity defined as having ≥2 relapses in the first year prior to start of subcutaneous interferon β-1a, three times weekly

ISSN: 1471-2377