title: Incidence of rare systemic rheumatic and connective tissue diseases in Finland.
abstract: OBJECTIVE
  To obtain information on the incidence of rare systemic rheumatic and connective tissue diseases in Finland.
  
  
  METHODS
  Population-based epidemiological study.
  
  
  METHODS
  Five out of 21 central hospital districts in Finland (population: about 1 million adults > or = 16 years of age).
  
  
  METHODS
  Subjects entitled under the nationwide sickness insurance scheme to receive specially reimbursed medication for rare systemic rheumatic or connective tissue diseases in 1990.
  
  
  METHODS
  Incidence.
  
  
  RESULTS
  A total of 30 incident cases occurred. Nine patients had mixed connective tissue disease, four had systemic sclerosis, four had dermato/polymyositis and one patient had inclusion body myositis; the corresponding annual incidence rates were 8, 4, 4 and 1/million of the adult population. Only one patient had adult Still's disease. The overall annual incidence rate of systemic vasculitides was 9/million of the adult population.
  
  
  CONCLUSIONS
  This study provides population-based figures on the incidence of rare systemic rheumatic and connective tissue diseases in Finland.
authors.affiliation: Department of Medicine, Kuopio University Hospital, Finland.
authors.forename: O
authors.initials: O
authors.lastname: Kaipiainen-Seppänen
authors.forename: K
authors.initials: K
authors.lastname: Aho
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003240:Connective Tissue Diseases / Q000453:epidemiology*; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012216:Rheumatic Diseases / Q000453:epidemiology*