title: Reproducibility of left ventricular mass by echocardiogram in the ELSA-Brasil.
abstract: BACKGROUND
  Echocardiography, though non-invasive and having relatively low-cost, presents issues of variability which can limit its use in epidemiological studies.
  
  
  OBJECTIVE
  To evaluate left ventricular mass reproducibility when assessed at acquisition (online) compared to when assessed at a reading center after electronic transmission (offline) and also when assessed by different readers at the reading center.
  
  
  METHODS
  Echocardiographers from the 6 ELSA-Brasil study investigation centers measured the left ventricular mass online during the acquisition from 124 studies before transmitting to the reading center, where studies were read according to the study protocol. Half of these studies were blindly read by a second reader in the reading center.
  
  
  RESULTS
  From the 124 echocardiograms, 5 (4%) were considered not measurable. Among the remaining 119, 72 (61%) were women, mean age was 50.2 ± 7.0 years and 2 had structural myocardial abnormalities. Images were considered to be optimal/ good by the reading center for 110 (92.4%) cases. No significant difference existed between online and offline measurements (1,29 g, CI 95% -3.60-6.19), and the intraclass correlation coefficient between them was 0.79 (CI 95% 0.71-0.85). For images read by two readers, the intraclass correlation coefficient was 0.86 (CI 95% 0.78-0.91).
  
  
  CONCLUSIONS
  There were no significant drifts between online and offline left ventricular mass measurements, and reproducibility was similar to that described in previous studies. Central quantitative assessment of echocardiographic studies in reading centers, as performed in the ELSA-Brasil study, is feasible and useful in clinical and epidemiological studies performed in our setting.
authors.affiliation: Programa de Pós-Graduação em Epidemiologia, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Alexandre Pereira
authors.initials: AP
authors.lastname: Tognon
authors.affiliation: Programa de Pós-Graduação em Epidemiologia, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Murilo
authors.initials: M
authors.lastname: Foppa
authors.affiliation: Programa de Pós-Graduação em Epidemiologia, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Vivian Cristine
authors.initials: VC
authors.lastname: Luft
authors.affiliation: The University of North Carolina, Chapel Hill, NC, Estados Unidos.
authors.forename: Lloyd Ellwood
authors.initials: LE
authors.lastname: Chambless
authors.affiliation: Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Paulo
authors.initials: P
authors.lastname: Lotufo
authors.affiliation: Universidade Federal do Espírito Santo, Vitória, Espírito Santo, Brazil.
authors.forename: Lilia Maria Mameri
authors.initials: LM
authors.lastname: El Aouar
authors.affiliation: Universidade Federal da Bahia, Salvador, Bahia, Brazil.
authors.forename: Luciana Pereira
authors.initials: LP
authors.lastname: Fernandes
authors.affiliation: Programa de Pós-Graduação em Epidemiologia, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Bruce Bartholow
authors.initials: BB
authors.lastname: Duncan
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001938:Brazil; D004452:Echocardiography / Q000379:methods / Q000592:standards; D005260:Female; D006352:Heart Ventricles / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results