Neurology. 2003 Nov 25;61(10):1373-1377
Mayr WT, Pittock SJ, McClelland RL, Jorgensen; NW, Noseworthy JH, Rodriguez M.
Departments of Neurology (Drs. Mayr, Pittock, Noseworthy, and Rodriguez) and Biostatistics (Dr. McClelland and N.W. Jorgensen), Mayo Clinic, and Mayo Medical and Graduate School (Dr. Rodriguez), Rochester, MN.
Epidemiologic data for multiple sclerosis (MS) in Olmsted County, MN, have been recorded for almost 100 years and have indicated that the increasing prevalence rate was likely due in part to an increasing incidence rate.
All cases of MS diagnosed from 1985 to 2000 were identified using the centralized diagnostic index at the Mayo Clinic and the Rochester Epidemiology Program Project, a shared database of all medical practitioners in the county.
Patients were required to have established residency at least 1 year prior to diagnosis of MS.
Results were also age- and sex-adjusted to control for shifts in the population structure.
The raw prevalence of MS was determined to be 177 per 100,000 on December 1, 2000, and the raw incidence rate was 7.5 per 100,000 person-years at risk from 1985 to 2000.
After age and sex adjustment to a common population, these prevalence and incidence rates of MS appear to have been stable rather than increasing over the past 20 years.