title: Design, baseline characteristics and carotid intima-media thickness reproducibility in the PARC study.
abstract: BACKGROUND
  Intima-media thickness (IMT) is associated with an increased risk of cardiovascular and cerebral ischemic events, but its correlation with the absolute cardiovascular risk is not known in large populations. The Paroi Arterielle et Risque Cardiovasculaire (PARC) Study is an epidemiological study designed to correlate conventional assessment of cardiovascular risk with the mean IMT of the common carotid.
  
  
  METHODS
  In the PARC study, 6,416 subjects were enrolled, including 80.7% subjects with cardiovascular risk factors and 19.3% without. A specific methodology was designed to harmonize the acquisition and processing of data at the 283 centers. Interreader agreement on image quality and IMT measurement of the common carotid artery (CCAIMT) was assessed from a random sample of 10% of the PARC study population.
  
  
  RESULTS
  The intraclass correlation coefficient was 0.98 (95% CI 0.966-0.985), and the accuracy was high (standard deviation of the error measurement: 0.0185 mm).
  
  
  CONCLUSIONS
  The reproducibility of the measurements assessed by means of the intraclass correlation coefficient and the accuracy of the CCAIMT measurement obtained in the PARC Study demonstrate the feasibility of large multicenter studies of IMT measurement.
authors.affiliation: Department of Neurology and Stroke Center, Bichat Claude Bernard University Hospital and Medical School, Denis Diderot University Paris-VII, Paris, France.
authors.forename: P J
authors.initials: PJ
authors.lastname: Touboul
authors.forename: E
authors.initials: E
authors.lastname: Vicaut
authors.forename: J
authors.initials: J
authors.lastname: Labreuche
authors.forename: J P
authors.initials: JP
authors.lastname: Belliard
authors.forename: S
authors.initials: S
authors.lastname: Cohen
authors.forename: S
authors.initials: S
authors.lastname: Kownator
authors.forename: I
authors.initials: I
authors.lastname: Pithois-Merli
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D008078:Cholesterol, LDL / Q000097:blood; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012307:Risk Factors; D017539:Tunica Intima / Q000000981:diagnostic imaging; D017540:Tunica Media / Q000000981:diagnostic imaging; D014463:Ultrasonography / Q000592:standards*
chemical_list: D008078:Cholesterol, LDL