High incidence and increasing prevalence of multiple sclerosis in British Columbia, Canada: findings from over two decades (1991–2010)

Abstract

Province-wide population-based administrative health data from British Columbia (BC), Canada (population: approximately 4.5 million) were used to estimate the incidence and prevalence of multiple sclerosis (MS) and examine potential trends over time. All BC residents meeting validated health administrative case definitions for MS were identified using hospital, physician, death, and health registration files. Estimates of annual prevalence (1991–2008), and incidence (1996–2008; allowing a 5-year disease-free run-in period) were age and sex standardized to the 2001 Canadian population. Changes over time in incidence, prevalence and sex ratios were examined using Poisson and log-binomial regression. The incidence rate was stable [average: 7.8/100,000 (95 % CI 7.6, 8.1)], while the female: male ratio decreased (p = 0.045) but remained at or above 2 for all years (average 2.8:1). From 1991–2008, MS prevalence increased by 4.7 % on average per year (p < 0.001) from 78.8/100,000 (95 % CI 75.7, 82.0) to 179.9/100,000 (95 % CI 176.0, 183.8), the sex prevalence ratio increased from 2.27 to 2.78 (p < 0.001) and the peak prevalence age range increased from 45–49 to 55–59 years. MS incidence and prevalence in BC are among the highest in the world. Neither the incidence nor the incidence sex ratio increased over time. However, the prevalence and prevalence sex ratio increased significantly during the 18-year period, which may be explained by the increased peak prevalence age of MS, longer survival with MS and the greater life expectancy of women compared to men.

ECTRIMS/EAN Guideline on the pharmacological treatment of people with multiple sclerosis

“…1 The incidence of MS varies across regions, with rates as high as 8 to 10 new cases per 100,000 in high latitudinal regions. 2,3 Current estimates suggest that over 700,000 people are affected in Europe, with over 2.5 million cases worldwide, 4 which represent a significant burden in terms of impact on quality of life, societal costs and personal expenses. 5,6 Most patients (85%-90%) have a relapsing course from onset that is characterized by relapses and remissions of neurological symptoms Methods: This guideline has been developed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology and following the updated EAN recommendations.…”

Multiple sclerosis in Canada 2011 to 2031: results of a microsimulation modelling study of epidemiological and economic impacts

“…Incidence and prevalence rates estimated from the British Columbia (BC) population were of comparable magnitude to those of the published studies from Canadian settings and provincial/territorial pilots. [22][23][24][25] Using these age-and sex-specific incidence rates, actors were classified as being diagnosed with MS, based on each actor's risk of developing MS at the beginning of each new calendar year. Incident MS cases accumulated over time to generate prevalent cases of MS.…”

Prevalence of Multiple Sclerosis in Saudi Arabia

“…A study conducted in Santarém -a district in the center of Portugal the crude prevalence rate found was 46.3/100,000. According to a Canadian study conducted through tow decades the province of British Columbia founded to have a prevalence rate that is among the highest globally 5 .…”