Table 3.

Relapse characteristics according to discontinuation status at 1, 2 and 3 years

	sc IFN β-1a tiw
	Follow-up at 1 year		Follow-up at 2 years		Follow-up at 3 years
	Continued	Discontinued	Continued	Discontinued	Continued	Discontinued
Total patients, n (%)	2505 (63.0)	1470 (37.0)	1310 (50.5)	1282 (49.5)	736 (44.2)	928 (55.8)
Relapses per year, mean (SD)	0.18 (0.52)	0.32 (0.67)	0.14 (0.34)	0.26 (0.49)	0.12 (0.26)	0.23 (0.42)
Patients with high relapses, n (%)a	97 (3.9)	84 (5.7)	46 (3.5)	73 (5.7)	21 (2.9)	52 (5.6)

IFN, interferon, 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