Table 1.

Demographic characteristics and VZV history of respondents

Age at last clinic visit (mean (SD))	53 (11)
Female (%)	73.2
Clinical phenotype at last clinic visit (%)
Relapsing remitting	49.3
Primary progressive	8.7
Secondary progressive	32.4
Unknown	9.6
Disease duration, years (mean (SD))	19.3 (10.7)
Chickenpox
Ever had chickenpox (%)
No	5.6
Yes	85.9
Don’t know	8.4
Age at the time of chickenpox (mean (SD))	10 (8)
Interval between chickenpox and onset of MS (mean (SD), range)	25 (13), − 39 to 60
Job that may involve contact with chickenpox (%)
Never	51.6
Past	35.9
Now	12.5
Zoster (shingles)
Ever had zoster (%)
No	78
Once	14
More than once	3.5
Don’t know	4.4
Age at the time of first zoster (mean (SD))	37 (16)
Timing of first zoster episode (%)
Before MS onset	56
- Median time to MS (years)	8
After MS onset	42
- Median time after MS (years)	15
Don’t know	2