title: CT colonography: interpretative performance in a non-academic environment.
abstract: OBJECTIVE
  To investigate interpretative accuracy and reporting time for radiologists performing computed tomography (CT) colonography in day-to-day non-academic clinical practice.
  
  
  METHODS
  Thirteen radiologists from seven centres, who were reporting CT colonography in non-academic daily clinical practice, interpreted a dataset of 15 colonoscopically validated cases in a controlled environment. Ten cases had either a cancer or polyp >10mm; one case had a medium polyp and four were normal. Correct case categorization and interpretation times were compared using analysis of variance to aggregated results obtained from both experienced observers and observers recently trained using 50 cases, working in an academic environment. The effect of experience was determined using Spearman's rank correlation.
  
  
  RESULTS
  Individual accuracy was highly variable, range 53% (95% CI 27-79%) to 93% (95% CI 68-100%). Mean accuracy overall was significantly inferior to experienced radiologists (mean 75 versus 88%, p=0.04) but not significantly different from recently trained radiologists (p=0.48). Interpretation time was not significantly different to experienced readers (mean 12.4 min versus 11.7, p=0.74), but shorter than recently trained radiologists (p=0.05). There was a significant, positive, linear correlation between prior experience and accuracy (p<0.001) with no plateau.
  
  
  CONCLUSIONS
  Accuracy for sub-specialist radiologists working in a non-academic environment is, on average, equivalent to radiologists trained using 50 cases. However, there is wide variability in individual performance, which generally falls short of the average performance suggested by meta-analysis of published data. Experience improves accuracy, but alone is insufficient to determine competence.
authors.affiliation: University College Hospital, London, UK.
authors.forename: D
authors.initials: D
authors.lastname: Burling
authors.forename: S
authors.initials: S
authors.lastname: Halligan
authors.forename: J
authors.initials: J
authors.lastname: Atchley
authors.forename: R
authors.initials: R
authors.lastname: Dhingsar
authors.forename: P
authors.initials: P
authors.lastname: Guest
authors.forename: S
authors.initials: S
authors.lastname: Hayward
authors.forename: A
authors.initials: A
authors.lastname: Higginson
authors.forename: C
authors.initials: C
authors.lastname: Jobling
authors.forename: C
authors.initials: C
authors.lastname: Kay
authors.forename: R
authors.initials: R
authors.lastname: Lilford
authors.forename: G
authors.initials: G
authors.lastname: Maskell
authors.forename: I
authors.initials: I
authors.lastname: McCafferty
authors.forename: J
authors.initials: J
authors.lastname: McGregor
authors.forename: D
authors.initials: D
authors.lastname: Morton
authors.forename: M
authors.initials: M
authors.lastname: Kumar Neelala
authors.forename: M
authors.initials: M
authors.lastname: Noakes
authors.forename: A
authors.initials: A
authors.lastname: Philips
authors.forename: P
authors.initials: P
authors.lastname: Riley
authors.forename: A
authors.initials: A
authors.lastname: Taylor
authors.forename: P
authors.initials: P
authors.lastname: Bassett
authors.forename: J
authors.initials: J
authors.lastname: Wardle
authors.forename: W
authors.initials: W
authors.lastname: Atkin
authors.forename: S A
authors.initials: SA
authors.lastname: Taylor
mesh_terms: D002983:Clinical Competence / Q000592:standards*; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging; D003111:Colonic Polyps / Q000000981:diagnostic imaging; D023881:Colonography, Computed Tomographic / Q000592:standards*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D015588:Observer Variation; D013997:Time Factors