Table 2.

Characteristics of the Swedish and Canadian cohorts used to build and externally validate the decision tree classifier.

	Swedish cohort			Canadian cohort
	Remained in the relapsing–remitting phase at the most recent clinic visit (n = 9,830)	Reached secondary progressive phase at the most recent clinic visit (n = 4,557)	All (n = 14,387)	All (n = 5,431)
Age at the most recent clinic visit mean (SD) (years)	44.0 (11.5)	58.4 (9.7)	48.6 (12.9)	47.0 (11.3)
Sex (female%)	7056 (71.8%)	3211 (70.5%)	10,267 (71.4%)	4432 (74.0%)
Multiple sclerosis symptom onset age mean (SD) (years)	32.1 (10.0)	33.0 (10.5)	32.4 (10.2)	31.6 (9.6)
Disease duration at the most recent clinic visit (years) (median [IQR])	10.0 [5.0–17.0]	25.0 [17.0–33.0]	14.0 [7.0–23.0]	14.0 [7.0–22.0]
Most recent EDSS score (median [IQR])	1.5 [1.0–2.5]	6.5 [4.5–7.5]	2.5 [1.0–5.0]	3.5 [1.5–5.5]

EDSS: expanded disability status scale, IQR: interquartile range, SD: standard deviation.