Geographic distribution of Multiple Sclerosis (MS) mortality rates in Canada, 1975-2009

Background: Our study examined whether there are differences in MS mortality rates across regions of Canada, which might suggest differences in environment or health care practice that influence outcome. Methods: Statistics Canada data on deaths due to MS and populations at risk, 1975-2009, were derived from the Research Data Centre, University of Alberta. Mortality rates and 95% confidence intervals (CIs) were calculated per 100,000 population for the Atlantic Provinces, Quebec, Ontario and Western Provinces (including Northwest Territories, Yukon, Nunavut), age-standardized to the 2006 population. Results: The average annual MS mortality rates for 1975-2009 per 100,000 population (CIs) were: Atlantic Provinces 1.09 (0.43,1.74); Quebec 1.30 (0.89,1.71); Ontario 1.08 (0.77,1.38); Western Provinces 1.39 (0.99,1.78). Female mortality rates were consistently higher than male rates but there were no differences in the female:male mortality rate ratios across regions. Trend analysis showed that rates were stable over the 35 year time span in 3 regions with non-significant average annual per cent increases/decreases of: Atlantic Provinces –0.43%; Quebec +0.12%; and Western Provinces +0.27%. Only Ontario showed a slight but significant increase of +0.81% (p