Interobserver agreement for colposcopy quality control using digitized colposcopic images during the ALTS trial.
OBJECTIVE
To estimate interobserver agreement among colposcopy quality control reviewers viewing digitized cervical images during the Atypical Squamous Cells of Undetermined Significance/Low-Grade Squamous Intraepithelial Lesion Triage Study (ALTS).


METHODS
Three colposcopy quality control reviewers independently examined modem-transferred digitized colposcopic images from subjects examined at four clinical centers. Reviewers indicated colposcopic impression, Reid colposcopic index scores, lesion size, and the technical quality of the image. Rates of agreement were evaluated using the kappa statistic and McNemar and Bowker tests of symmetry.


RESULTS
Regarding colposcopic impressions, the average weighted kappa for pairs of initial reviewers was 0.36 (95% confidence interval, 0.33-0.39). kappa scores with respect to Reid colposcopic index, cervical image quality, and lesion size ranged from 0.23 to 0.28, 0.18 to 0.27, and 0.33 to 0.42, respectively.


CONCLUSIONS
Fair rates of agreement and poor to fair kappa scores among ALTS colposcopy quality control reviewers were noted for colposcopic impression, Reid colposcopic index scores, image quality, and lesion size. Great latitude exists in the interpretation of digitized cervical images. Poor image quality partially may explain these suboptimal results.
Ferris
Daron G
DG
Gynecologic Cancer Prevention Center, Department of Family Medicine, The Medical College of Georgia, Augusta, GA 30912, USA. dferris@mail.mcg.edu
Litaker
Mark
M
D002584:Cervix Uteri / Q000473:pathology; D003127:Colposcopy / Q000379:methods / Q000592:standards*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D015588:Observer Variation; D011786:Quality Control; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis*; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis*