Prevalence of multiple sclerosis in Saskatoon.

In an epidemiologic survey based on a search of all available medical records for 1955 to 1980 at the city's three general hospitals the prevalence in Saskatoon of probable multiple sclerosis was found to be 111/100,000 and that of combined probable and possible multiple sclerosis 134/100,000 on Jan. 1, 1977. The average annual incidence over the three decades was 4.8/100,000. These prevalence and incidence rates were two to three time greater than those reported for other Canadian cities. Of the 150 individuals with probable multiple sclerosis 87 were living in Saskatoon at the time of onset of the disease; thus, the prevalence of the disease among residents was 64/100,000. The prevalence was 77/100,000 among Saskatchewan-born residents, including those born in Saskatoon, and 48/100,000 among immigrants from other provinces and outside Canada.