Figure 4. Kaplan-Meier survival analysis comparing relapse-free periods without medications between 0 and 24 months from onset and later.

The analysis compared the relapse-free period without relapse-preventive therapies between 0 and 24 months from the onset (36 patients with no relapse-preventive therapy) and 24–48 months from the onset (14 patients without relapses in the first 24 months). The latter group represents the “nonclustered” intermittent period status. The former group showed a shorter relapse-free period and a higher relapse rate than the latter group (p = 0.0206, generalized Wilcoxon test).