A prevalence study of multiple sclerosis in the Crowsnest Pass region of southern Alberta.

Reports of a high prevalence rate for multiple sclerosis in Southern Alberta led to an epidemiologic study of this disease in the Crowsnest Pass and Cardston regions. In Cardston, the prevalence rate for multiple sclerosis was 88 per 100,000. In the Crowsnest Pass, the prevalence rate was 217 per 100,000. Previous epidemiologic studies of the prevalence rate of multiple sclerosis in Western Canada have shown rates between 93 and 111 per 100,000. Two prevalence studies of multiple sclerosis in Barrhead County, Alberta and Westlock County, Alberta show prevalence rates of 196 and 201 per 100,000. The prevalence rate in the Crowsnest Pass is comparable to the prevalence in Barrhead County and Westlock County, Alberta. However, there is no statistically significant difference between prevalence rates in the Cardston and Crowsnest Pass regions and our overall feeling is that the results of studies of small populations should be interpreted with caution.