title: Incidental findings on chest CT imaging are associated with increased COPD exacerbations and mortality.
abstract: BACKGROUND
  This study aimed to evaluate whether incidental CT findings of emphysema, airway thickening and bronchiectasis, as seen on CT scans performed for other non-pulmonary clinical indications, are associated with future acute exacerbations of COPD resulting in hospitalisation or death.
  
  
  METHODS
  This multicentre prospective case-cohort study comprised 6406 subjects who underwent routine diagnostic chest CT for non-pulmonary indications. Using a case-cohort approach, we visually graded CT scans from cases and a random sample of ∼10% of the baseline cohort (n=704) for emphysema severity (range 0-20), airway thickening (range 0-5) and bronchiectasis (range 0-5). We used weighted Cox proportional hazards analysis to assess the independent association between CT findings and hospitalisation or death due to COPD exacerbation.
  
  
  RESULTS
  During a median follow-up of 4.4 years (maximum 5.2 years), 338 COPD events were identified. The risk of experiencing a future acute exacerbation of COPD resulting in hospitalisation or death was significantly increased in subjects with severe emphysema (score ≥7) and severe airway thickening (score ≥3). The respective HRs were 4.6 (95% CI 3.0 to 7.1) and 5.9 (95% CI 3.4 to 10.5). Severe bronchiectasis (score ≥3) was not significantly associated with increased risk of adverse events (HR 1.5; 95% CI 0.9 to 2.5).
  
  
  CONCLUSIONS
  Morphological correlates of COPD such as emphysema and airway thickening detected on CT scans obtained for other non-pulmonary indications are strong independent predictors of subsequent development of acute exacerbations of COPD resulting in hospitalisation or death.
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Pushpa M
authors.initials: PM
authors.lastname: Jairam
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: van der Graaf
authors.affiliation: Department of Pulmonology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Jan-Willem J
authors.initials: JW
authors.lastname: Lammers
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Willem P Th M
authors.initials: WP
authors.lastname: Mali
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Pim A
authors.initials: PA
authors.lastname: de Jong
mesh_terms: D000368:Aged; D001987:Bronchiectasis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000401:mortality; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging* / Q000401:mortality*; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000209:etiology / Q000401:mortality; D013902:Radiography, Thoracic / Q000379:methods*; D012008:Recurrence; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D014057:Tomography, X-Ray Computed
keywords: Bronchiectasis; COPD Exacerbations; COPD epidemiology; Clinical Epidemiology; Emphysema; Imaging/CT MRI etc