Incidence of Multiple Sclerosis and Related Disorders in Asian Populations of British Columbia.
BACKGROUND
Global variation in the incidence of multiple sclerosis (MS) is generally ascribed to differences in genetic and environmental risk factors. Here we investigate temporal trends in the incidence of MS and related disorders in British Columbia, Canada, from 1986 to 2010, focusing particularly on the Asian ethnic subpopulation.


METHODS
A longitudinal database was screened to identify newly diagnosed cases of MS and related disorders, including neuromyelitis optica and clinically isolated syndromes. Age-standardized, sex-specific mean annual incidence was calculated for the Asian and non-Asian population of British Columbia for 5-year intervals from 1986 to 2010. Temporal changes and cohort differences in incidence rates and demographic characteristics were evaluated.


RESULTS
During this period, the incidence of MS and related disorders in the non-Asian population remained relatively unchanged, from 10.41 (95% confidence interval [CI]: 9.87-10.97) to 9.91 (95% CI: 9.46-10.39) per 100,000 (p=0.167). In contrast, incidence in the Asian population doubled during the same period. This increase was driven by a precipitous rise in the incidence of MS in females from 0.71 (95% CI: 0.01-1.50) to 2.08 (95% CI: 1.43-2.91) per 100,000 (p=0.004), including both Canadian-born and immigrant Asians. The incidence of neuromyelitis optica did not change significantly during this period.


CONCLUSIONS
The incidence of MS may be increasing among females in the Asian ethnic population of British Columbia.
['Lee|Joshua D|JD|', 'Guimond|Colleen|C|', 'Yee|Irene M|IM|', 'Vilariño-Güell|Carles|C|', 'Wu|Zhi-Ying|ZY|', 'Traboulsee|Anthony L|AL|', 'Sadovnick|A Dessa|AD|']
D000328:Adult D017668:Age of Onset D000368:Aged D001213:Asian Americans D001955:British Columbia D016208:Databases, Factual D054242:Emigrants and Immigrants D005260:Female D006801:Humans D015994:Incidence D008297:Male D008875:Middle Aged D009103:Multiple Sclerosis D009471:Neuromyelitis Optica D012737:Sex Factors D012959:Socioeconomic Factors
Incidence Multiple sclerosis Neuromyelitis optica