Table 1. Demographic characteristics of cases, age-matched controls and past lifetime risk controls.

Characteristic	Cases (%)	Age-matched controls (%)	1936 Controls (%)
Number	88	88	87
Sex
Female	64 (72.7)	62 (70.5)	61 (70.1)
Male	24 (27.3)	26 (29.5)	26 (29.9)
Female:male ratio	2.67:1	2.34:1	2.35:1
Place of residence
Orkney	37 (42)	54 (61)	55 (63)
Shetland	21 (24)	29 (33)	30 (34)
Grampian	16 (18)	4 (5)	0 (0)
Highland	7 (8)	0 (0)	1 (1)
Lothian	4 (5)	1 (1)	1 (1)
Fife	1 (1)	0 (0)	0 (0)
Strathclyde	1 (1)	0 (0)	0 (0)
USA	1 (1)	0 (0)	0 (0)
Age (years)
Age at onset of disease
Mean (n=87)	32
Range	8–63
Age at diagnosis
Mean (n=85)	40
Range	8–76
Age at time of interview
Mean	50.7	50	72.8
Range	27.4–77.0	26.9–76.7	70.1–89.2
Disease course
Relapsing-remitting type	35 (39.8)
Secondary progressive – with relapses	26 (29.5)
Secondary progressive – without relapses	15 (17.0)
Primary progressive	12 (13.6)
Clinically isolated syndrome	0 (0)
Expanded disability status score
<3	27 (30.7)
3–<6	12 (13.6)
6–<7	29 (33.0)
≥7	20 (22.7)