title: Systematic review of pleural plaques and lung function.
abstract: BACKGROUND
  US EPA proposed a Reference Concentration for Libby amphibole asbestos based on the premise that pleural plaques are adverse and cause lung function deficits.
  
  
  OBJECTIVE
  We conducted a systematic review to evaluate whether there is an association between pleural plaques and lung function and ascertain whether results were dependent on the method used to identify plaques.
  
  
  METHODS
  Using the PubMed database, we identified studies that evaluated pleural plaques and lung function. We assessed each study for quality, then integrated evidence and assessed associations based on the Bradford Hill guidelines. We also compared the results of HRCT studies to those of X-ray studies.
  
  
  RESULTS
  We identified 16 HRCT and 36 X-ray studies. We rated six HRCT and 16 X-ray studies as higher quality based on a risk-of-bias analysis. Half of the higher quality studies reported small but statistically significant mean lung function decrements associated with plaques. None of the differences were clinically significant. Many studies had limitations, such as inappropriate controls and/or insufficient adjustment for confounders. There was little consistency in the direction of effect for the most commonly reported measurements. X-ray results were more variable than HRCT results. Pleural plaques were not associated with changes in lung function over time in longitudinal studies.
  
  
  CONCLUSIONS
  The weight of evidence indicates that pleural plaques do not impact lung function. Observed associations are most likely due to unidentified abnormalities or other factors.
authors.affiliation: Gradient Corporation , Cambridge, MA , USA and.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Kerper
authors.forename: Heather N
authors.initials: HN
authors.lastname: Lynch
authors.forename: Ke
authors.initials: K
authors.lastname: Zu
authors.forename: Ge
authors.initials: G
authors.lastname: Tao
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Utell
authors.forename: Julie E
authors.initials: JE
authors.lastname: Goodman
mesh_terms: D006801:Humans; D008137:Longitudinal Studies; D008168:Lung / Q000000981:diagnostic imaging / Q000502:physiology*; D010995:Pleural Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology*; D011859:Radiography; D013147:Spirometry
keywords: Asbestos; FEV; FVC; X-ray; high-resolution computed tomography; lung function; pleural plaques