title: Impact of observer experience on the reproducibility of transient elastometry in HIV/HCV co-infected patients.
abstract: BACKGROUND
  Data on the influence of observer experience on transient elastometry (TE) in hepatitis C virus (HCV) infection are scarce, and there are no data on HCV/HIV co-infected patients.
  
  
  METHODS
  TE determination was conducted by an experienced and an inexperienced observer in 93 patients who were divided into three groups according to the chronological order of their attendance. The interobserver variability of TE results was analyzed by the intraclass correlation index (ICC) and the interobserver agreement of the classification of significant fibrosis and cirrhosis by the kappa index.
  
  
  RESULTS
  The overall ICC was 0.970 (95% confidence interval [CI] 0.954-0.980). For groups 1, 2, and 3, the ICCs were 0.952 (95% CI 0.901-0.977), 0.966 (95% CI 0.931-0.984), and 0.986 (95% CI 0.971-0.993), respectively. The kappa index for the classification of cirrhosis (cutoff value >or=14.6 kPa) for the three groups was 0.53, 1.00, and 0.91. The use of two cutoff points to exclude (<6 kPa) or diagnose significant fibrosis (>9 kPa) yielded a kappa index of 0.72, 1.00, and 1.00, respectively.
  
  
  CONCLUSIONS
  In HIV/HCV co-infected patients, the concordance between an inexperienced and an experienced observer is acceptable after a short instruction period. To maximize this concordance, a training period of 60 measurements should be recommended.
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario de Valme, Seville, Spain.
authors.forename: Karin
authors.initials: K
authors.lastname: Neukam
authors.forename: Juan
authors.initials: J
authors.lastname: Macías
authors.forename: Concepción
authors.initials: C
authors.lastname: Ferrete
authors.forename: José C
authors.initials: JC
authors.lastname: Palomares
authors.forename: Ana
authors.initials: A
authors.lastname: Fernández
authors.forename: José A
authors.initials: JA
authors.lastname: Mira
authors.forename: Juan A
authors.initials: JA
authors.lastname: Pineda
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006678:HIV / Q000502:physiology*; D015658:HIV Infections / Q000503:physiopathology / Q000821:virology*; D016174:Hepacivirus / Q000502:physiology*; D019698:Hepatitis C, Chronic / Q000503:physiopathology / Q000821:virology*; D006801:Humans; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000821:virology; D008297:Male; D015588:Observer Variation; D011446:Prospective Studies; D014463:Ultrasonography; D055815:Young Adult