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Long-term outcome in polymyositis and dermatomyositis
  1. I M Bronner1,*,
  2. M F G van der Meulen2,*,
  3. M de Visser1,
  4. S Kalmijn3,
  5. W J van Venrooij4,
  6. A E Voskuyl5,
  7. H J Dinant6,
  8. W H J P Linssen7,
  9. J H J Wokke2,
  10. J E Hoogendijk2
  1. 1Department of Neurology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
  2. 2Department of Neurology, University Medical Centre Utrecht, Utrecht, The Netherlands
  3. 3Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht
  4. 4Department of Biochemistry, Centre for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, The Netherlands
  5. 5Depertment of Rheumatology, Free University Hospital Amsterdam, Amsterdam
  6. 6Department of Clinical Immunology and Rheumatology, Academic Medical Centre
  7. 7Department of Neurology, St Lucas Andreas Hospital Amsterdam, Amsterdam
  1. Correspondence to:
    M de Visser
    Department of Neurology, Academic Medical Centre, University of Amsterdam, PO Box 22660, 1100 DD Amsterdam, The Netherlands;m.devisser{at}


Background: Although polymyositis and dermatomyositis are regarded as treatable disorders, prognosis is not well known, as in the literature long-term outcome and prognostic factors vary widely.

Aim: To analyse the prognostic outcome factors in polymyositis and adult dermatomyositis.

Methods: We determined mortality, clinical outcome (muscle strength, disability, persistent use of drugs and quality of life) and disease course and analysed prognostic outcome factors.

Results: Disease-related death occurred in at least 10% of the patients, mainly because of associated cancer and pulmonary complications. Re-examination of 110 patients after a median follow-up of 5 years showed that 20% remained in remission and were off drugs, whereas 80% had a polycyclic or chronic continuous course. The cumulative risk of incident connective tissue disorder in patients with myositis was significantly increased. 65% of the patients had normal strength at follow-up, 34% had no or slight disability, and 16% had normal physical sickness impact profile scores. Muscle weakness was associated with higher age (odds ratio (OR) 3.6; 95% confidence interval (CI) 1.3 to 10.3). Disability was associated with male sex (OR 3.1; 95% CI 1.2 to 7.9). 41% of the patients with a favourable clinical outcome were still using drugs. Jo-1 antibodies predicted the persistent use of drugs (OR 4.4, 95% CI 1.3 to 15.0).

Conclusions: Dermatomyositis and polymyositis are serious diseases with a disease-related mortality of at least 10%. In the long term, myositis has a major effect on perceived disability and quality of life, despite the regained muscle strength.

  • CTD, connective tissue disorder
  • MRC, Medical Research Council
  • MSA, myositis-specific autoantibodies
  • s-IBM, sporadic inclusion body myositis
  • SIP, Sickness Impact Profile
  • SRP, signal recognition particle

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  • * These authors contributed equally to this work.

  • Published Online First 10 April 2006

  • Competing interests: None.

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