title: Influence of interstitial lung disease on outcome in systemic sclerosis: a population-based historical cohort study.
abstract: BACKGROUND
  Interstitial lung disease (ILD) is a frequent complication of systemic sclerosis (SSc) and a major cause of SSc-related deaths. This study aimed to determine the influence of ILD on SSc in a population-based historical cohort study. The hypothesis was that patients with SSc who develop ILD have increased morbidity and mortality when compared with patients with SSc without ILD.
  
  
  METHODS
  Using the record linkage system of the Rochester Epidemiology Project in Olmsted County, Minnesota, this study identified the incidence of SSc between 1980 and 2010 and point prevalence on December 31, 2010 and determined the progression of organ involvement and its influence on outcome.
  
  
  RESULTS
  During the 30-year interval, we identified 64 incident cases of SSc: 57 women and seven men, median age 49.1 years (interquartile range [IQR], 39.8-67.6 years). There were 43 prevalent cases. ILD occurred in 19 cases, usually after the diagnosis of SSc (median, 2 years; IQR, 0-10 years), with only three cases occurring 6 to 24 months beforehand. Pulmonary arterial hypertension (PAH) was diagnosed in 14 cases, heart failure in 27 cases, and chronic kidney disease (CKD) in 21 cases. Seventeen patients died during the study period, with a median survival time after diagnosis of 22.9 years. ILD, PAH, and CKD were associated with an increased risk of death.
  
  
  CONCLUSIONS
  The incidence of ILD associated with SSc was relatively low in this population-based cohort. ILD appeared to be a contributing factor to mortality. Other factors, including age, PAH, and CKD, were also associated with poor outcome.
authors: Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN. Electronic address: bauer.philippe@mayo.edu.
authors: Philippe R
authors: PR
authors: Bauer
authors: Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN.
authors: Dante N
authors: DN
authors: Schiavo
authors: Rheumatology, Mayo Clinic, Rochester, MN.
authors: Thomas G
authors: TG
authors: Osborn
authors: Radiology-Diagnostic, Mayo Clinic, Rochester, MN.
authors: David L
authors: DL
authors: Levin
authors: Health Sciences Research-Epidemiology, Mayo Clinic, Rochester, MN.
authors: Jennifer
authors: J
authors: St Sauver
authors: Health Sciences Research-Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN.
authors: Andrew C
authors: AC
authors: Hanson
authors: Health Sciences Research-Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN.
authors: Darrell R
authors: DR
authors: Schroeder
authors: Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN.
authors: Jay H
authors: JH
authors: Ryu
mesh_terms: D000328:Adult; D000368:Aged; D018450:Disease Progression; D005260:Female; D006801:Humans; D015994:Incidence; D017563:Lung Diseases, Interstitial / Q000209:etiology* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors; D012595:Scleroderma, Systemic / Q000150:complications* / Q000401:mortality