Table 1 Characteristics of the prospective and retrospective multiple sclerosis cases

CharacteristicsProspectiveRetrospective
No. cases73161
Female sex67125
Source of samples
    Northern Sweden Health and Disease Study1298
    Northern Sweden Maternity Cohort6163
Serum collection
    Median age, y (range)28 (17–59)40 (19–68)
    Median year (range)1984 (1976–1995)1992 (1975–2000)
Duration between symptom onset and serum collection, y
    ≤11226
    2–41617
    5–92640
    10–141218
    ≥15760