title: [Reproducibility and accuracy of the diagnosis of cervical intraepithelial neoplasia (CIN) in 15 Italian laboratories: a national pilot project. Development of new indices of diagnostic variability. National Work Group for the expert quality control in cervico-vaginal cytopathology].
abstract: OBJECTIVE
  To assess reliability and accuracy of cervical smear diagnoses, to evaluate the effectiveness of the participation in a programme of slide exchange in increasing reliability and to re-examine the agreement in discriminating between CIN 2 and CIN 3 (merged in High grade SIL in the Bethesda System).
  
  
  METHODS
  15 laboratories participating on a voluntary basis throughout Italy, for a period of 1 year.
  
  
  METHODS
  Phase one: circulation of 40 slides including all main diagnostic categories; discussion of results by representatives of participating centres. Phase two: circulation of another 40 similar slides. For each slide, not only a diagnosis but also recommendations for further examinations and a judgment on diagnostic difficulty were asked. Common measures of reliability and accuracy and (the latter only for slides on which a consensus diagnosis was reached corresponding to the histological diagnosis) were calculated; three new indices of diagnostic variability were also computed.
  
  
  RESULTS
  Consensus diagnosis among representatives of participating laboratories on about 90% of the slides was reached both in the first and in the second phase. On 3 slides it was impossible to reach a consensus diagnosis even among external referees. In both phases, the study showed a marked variability among diagnoses, recommendations and judgment on diagnostic difficulty and, on some slides, a worrying lack of reliability in the determination of precancerous lesions. The agreement on discrimination between CIN 1 and CIN 2 was low, but it was slightly better between CIN 2 and CIN 3. No significant relationship between accuracy and workload was found. External quality control or better said, continuous quality improvement activities are essential but should be conducted in a more systematic way with greater involvement of cytotechnicians.
authors.affiliation: Laboritorio di Epidemiologia e Biostatistica, Istituto Superiore di Santià, Roma.
authors.forename: M
authors.initials: M
authors.lastname: Branca
authors.forename: P G
authors.initials: PG
authors.lastname: Duca
authors.forename: P
authors.initials: P
authors.lastname: Verderio
authors.forename: E
authors.initials: E
authors.lastname: Rossi
authors.forename: L
authors.initials: L
authors.lastname: Leoncini
authors.forename: E
authors.initials: E
authors.lastname: Turolla
authors.forename: P L
authors.initials: PL
authors.lastname: Morosini
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D010865:Pilot Projects; D015203:Reproducibility of Results; D002583:Uterine Cervical Neoplasms / Q000473:pathology*; D002578:Uterine Cervical Dysplasia / Q000473:pathology*
vernacular_title: Riproducibilità ed accuratezza nelle diagnosi di CIN in 15 laboratori italiani: progetto pilota nazionale. Messa a punto di nuovi indici clinici di variabilità diagnostica. Gruppo Nazionale di lavoro per il controllo di qualità esterno in Citopatologia cervico-vaginale.