Epidemiology of sporadic inclusion body myositis and polymyositis in Olmsted County, Minnesota
Wilson, F.C.; Ytterberg, S.R.; St Sauver, J.L.; Reed, A.M.
Journal of Rheumatology 35(3): 445-447
2008
ISSN/ISBN: 0315-162X PMID: 18203321 Document Number: 619488
Objective. To determine the incidence and prevalence of sporadic inclusion body myositis (sIBM) and polymyositis (PM) in a population-based study.Methods. Charts of patients with myositis in Olmsted County, Minnesota, USA, from 1981 to 2000 were reviewed.Results. For sIBM, the age- and sex-adjusted incidence rates per 100,000 were 0.79 (95% confidence interval = 0.24-1.35), and for PM, 0.41 (95% Cl 0.08-0.73). The age- and sex-adjusted prevalence rates per 100,000 were 7.06 (95% CI 0.87-13.24) for sIBM and 3.45 (95% CI 0.00-7.35) for PM.Conclusion. The incidence and prevalence rates for sIBM are higher than previously reported.