title: Why do patients with myositis die? A retrospective analysis of a single-centre cohort.
abstract: OBJECTIVE
  Causes of death in inflammatory myopathies have rarely been studied. We have assessed a cohort of myositis patients followed in a single centre over a 37-year period, reviewing the mortality rate, causes of death and predictors of poor prognosis.
  
  
  METHODS
  We performed a single-centre, retrospective study on patients aged ≥16 years fulfilling 3 or 4 of the Bohan and Peter criteria, noting their demographic data, clinical features, serology, treatment and outcome.
  
  
  RESULTS
  Of 97 patients identified, 74.2% were female. The mean age at diagnosis was 40.5 years (SD 13.2). 38.1% had adult-onset dermatomyositis, 36.1% adult-onset polymyositis and 25.8% overlap myositis. 96.9% had upper and lower limb involvement (UL+/LL+) and 62.9% had a highest CK≥10 times the upper limit of normal. 33% had significant infection(s). The disease course was chronic persistent in 29.9%, relapsing and remitting in 34% and monophasic in 36.1%. All received steroids and 92.8% other immunosuppressant(s). The median follow-up was 9 years (IQR 11.5). The estimated cumulative proportion survival at 5, 10, 15 and 20 years were 94.6%, 82.2%, 72,1% and 66.1%, respectively. 24.7% of patients died, mostly due to infection (29.2%). In univariate analysis, lung involvement (HR 1.78, p=0.013), infection (HR 4.18, p=0.003) and UL+/LL+ (HR 0.13, p=0.010) were statistically significantly associated with the risk of death. In the multivariate analysis infection (HR 3.68, p=0.009) and UL+/LL+ (HR 0.16, p=0.027) were statistically significantly associated with survival.
  
  
  CONCLUSIONS
  A good long-term survival is reported. Nevertheless, careful follow-up of myositis patients is important.
authors: Department of Internal Medicine, Hospital Distrital da Figueira da Foz, Coimbra, Portugal.
authors: Marta
authors: M
authors: Amaral Silva
authors: Department of Internal Medicine, Hospital Principe de Asturias, Alcala de Henares, Madrid, Spain.
authors: Estefania
authors: E
authors: Cogollo
authors: Centre for Rheumatology, Department of Medicine, University College London, UK. d.isenberg@ucl.ac.uk.
authors: David A
authors: DA
authors: Isenberg
mesh_terms: D000328:Adult; D002423:Cause of Death; D003141:Communicable Diseases / Q000401:mortality; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008171:Lung Diseases / Q000401:mortality; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009220:Myositis / Q000175:diagnosis / Q000401:mortality*; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult