title: Comparison of cytology proficiency testing: glass slides vs. virtual slides.
abstract: OBJECTIVE
  To compare proficiency testing in gynecologic cytology using glass slides vs. virtual slides.
  
  
  METHODS
  To compare performance, a sample of 111 individuals (pathologists = 52, cytotechnologists = 59) from participating in-state laboratories were administered 2 proficiency tests. The annual test of the Maryland Cytology Proficiency Testing Program (MCPTP) was administered to individuals in their laboratories following normal work practice (i.e., using microscopes and equipment with which they were familiar). The other test was CytoView II (Centers for Disease Control and Prevention, Atlanta, Georgia, U.S.A.), a computer-based test composed of virtual slides captured from the MCPTP's glass slides, which test administration personnel transported to the individual's laboratory and administered using 1 of 2 laptop computers. ANOVA was used to compare the performance on the 2 tests and the effect of various potential confounding variables. The slides were evaluated by comparing the performance average for each glass slide to that of the matching virtual slides. All data analysis was performed at the 95% confidence interval.
  
  
  RESULTS
  The mean score of the individuals (n = 111) on the MCPTP test was 99.2% (SD = 2.2, range = 90-100%). The mean score of the individuals (n = 111) on CytoView II was 96.8% (SD = 5.8, range = 70-100%). No individual scored < 90% on the glass slide test (pass rate = 100%). Eight individuals (pathologists = 3, cytotechnologists = 5) scored < 90% on the CytoView II (pass rate = 93.8%). Comparison of an individual's performance on the 2 tests demonstrated a significant difference. When virtual slides that did not attain a 90% consensus were excluded from the scoring, a comparison of individual pass rate for the glass slide test (100%) and computer-based test (99.1%) did not demonstrate significant difference.
  
  
  CONCLUSIONS
  Each slide (glass or virtual) must be field validated by cytotechnologists and pathologists. If field validation and Clinical Laboratory Improvement Amendment referencing of virtual slides are comparable to those of glass slides, computer-based testing can be equivalent.
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia 30341-3724, USA. mbg0@cdc.gov
authors.forename: MariBeth
authors.initials: M
authors.lastname: Gagnon
authors.forename: Stanley
authors.initials: S
authors.lastname: Inhorn
authors.forename: John
authors.initials: J
authors.lastname: Hancock
authors.forename: Barbara
authors.initials: B
authors.lastname: Keller
authors.forename: Dana
authors.initials: D
authors.lastname: Carpenter
authors.forename: Toby
authors.initials: T
authors.lastname: Merlin
authors.forename: Thomas
authors.initials: T
authors.lastname: Hearn
authors.forename: Pamela
authors.initials: P
authors.lastname: Thompson
authors.forename: Rhonda
authors.initials: R
authors.lastname: Whalen
mesh_terms: D003585:Cell Biology / Q000193:education / Q000592:standards*; D004521:Educational Measurement / Q000379:methods / Q000592:standards* / Q000706:statistics & numerical data; D005260:Female; D005833:Genital Neoplasms, Female / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D007755:Laboratories, Hospital / Q000592:standards / Q000639:trends; D008396:Maryland; D008853:Microscopy / Q000379:methods / Q000592:standards*; D015588:Observer Variation; D010338:Pathology, Clinical / Q000193:education / Q000592:standards*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012107:Research Design / Q000592:standards*; D014584:User-Computer Interface