title: Performance of 3 methods for quality control for gynecologic cytology diagnoses.
abstract: OBJECTIVE
  To evaluate performance and viability of internal quality control (QC) strategies in a public health laboratory of the state of São Paulo.
  
  
  METHODS
  A retrospective study was performed with 3 QC strategies to improve internal cytologic diagnoses: morphologic guided-list criteria (MGLC), 100% rapid-rescreening (100% RR) of negative slides ("turret" method) and 10% rescreening (10% R) of negative slides. Cases were examined at Adolfo Lutz Institute, São Paulo, Brazil, from 2002 to 2004. Histopathologic results, when available, were considered gold standard; cytologic consensus diagnosis was by 2 pathologists when histologic results were unavailable.
  
  
  RESULTS
  MGLC selected 20.7% samples with cytologic atypias, 10% R selected 0.6% and RR selected 2.5%. Cytologic/histologic initial concordance was 57.4%, low-grade squamous intra-epithelial lesion false negative rate was 34.9% and high-grade squamous intraepithelial lesion false negative rate was 12.2%. After diagnosis, consensus concordance was 97.2%.
  
  
  CONCLUSIONS
  The 100% RR and 10% R QC strategies detected more false negative cases in liquid-based cytology than in conventional Pap smears. The 100% RR strategy reduced the false negative results and allowed evaluation of individual staff performance. The 10% R strategy did not offer significant results. We concluded that association of MGLC and 100% RR strategies might improve cytologic diagnostic quality.
authors.affiliation: Pathology Division, Adolfo Lutz Institute, Department of Pathology, Federal University of São Paulo, Sã Paulo, Brazil.
authors.forename: Maria Lucia
authors.initials: ML
authors.lastname: Utagawa
authors.forename: Neuza Kasumi
authors.initials: NK
authors.lastname: Shirata
authors.forename: Maria da Gloria
authors.initials: Mda G
authors.lastname: Mattosinho de Castro Ferraz
authors.forename: Celso
authors.initials: C
authors.lastname: di Loreto
authors.forename: Miria
authors.initials: M
authors.lastname: Dall' Agnol
authors.forename: Adhemar
authors.initials: A
authors.lastname: Longatto-Filho
mesh_terms: D001938:Brazil; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D007753:Laboratories / Q000592:standards*; D065006:Papanicolaou Test; D011237:Predictive Value of Tests; D011785:Quality Assurance, Health Care; D011786:Quality Control; D012189:Retrospective Studies; D002583:Uterine Cervical Neoplasms / Q000473:pathology*; D014626:Vaginal Smears / Q000592:standards*; D002578:Uterine Cervical Dysplasia / Q000473:pathology*