Characteristics of the British Columbia multiple sclerosis cohort
| Patient characteristics (n=6917*) | n (%) |
| Sex | |
| Male | 1919 (28) |
| Female | 4998 (72) |
| Disease course | |
| Relapsing onset† | 6172 (89) |
| Primary progressive | 694 (10) |
| Age at symptom onset (years) | |
| <20 | 646 (9) |
| 20–<30 | 2415 (35) |
| 30–<40 | 2205 (32) |
| ≥40 | 1634 (24) |
| Age (years) | |
| <30‡ | 1091 (16) |
| 30—<40 | 2128 (31) |
| 40–<50 | 2119 (31) |
| ≥50 | 1579 (23) |
| Disease duration (years) | |
| <5‡ | 3088 (45) |
| 5–<9 | 1212 (18) |
| 9–<15 | 1123 (16) |
| ≥15 | 1477 (21) |
| Time period | |
| 1980–1985 | 1178 (17) |
| 1986–1991 | 1164 (17) |
| 1992–1997 | 1767 (26) |
| 1998–2004 | 2808 (41) |
↵* Clinical course unknown for 51 (1%) patients; age at symptom onset (and hence disease duration) unknown for 17 (<1%) patients.
↵† Relapsing onset cohort includes those who later became secondary progressive.
↵‡ Age and disease duration measured at cohort entry (date of first visit to a British Columbia multiple sclerosis clinic).