Cervical Cancer Screening in Cameroon: Interobserver Agreement on the Interpretation of Digital Cervicography Results

Abstract

OBJECTIVE: The World Health Organization recommends visual inspection with acetic acid (VIA) for cervical cancer screening in resource-limited settings. In Cameroon, we use digital cervicography (DC) to capture images of the cervix after VIA. This study evaluated interobserver agreement of DC results, compared DC with histopathologic results, and examined interobserver agreement among screening methods. METHOD: Three observers, blinded to each other's interpretations, evaluated 540 DC photographs as follows: (1) negative/positive for acetowhite lesions or cancer and (2) assigned a presumptive diagnosis of histopathologic lesion grade in the 91 cases that had a histopathologic diagnosis. Observer A was the actual screening nurse; B, a reproductive health nurse; C, a gynecologic oncologist; and D, the histopathologic diagnosis. We compared inter-rater agreement of DC impressions among observers A, B, and C, and with D, with Cohen kappas. RESULTS: For interpretations of DC, (negative/positive) strengths of agreement of paired observers were the following: A/B, moderate [K, 0.54; 95% confidence interval (CI), 0.47-0.61], A/C, fair (K, 0.37; 95% CI, 0.29-0.44), and B/C, moderate (K, 0.45; 95% CI, 0.37-0.53). For presumptive pathologic grading, strengths of agreement for weighted Ks were as follows: A/B, moderate (K, 0.42; 95% CI, 0.28-0.56); A/C, fair (K, 0.33; 95% CI, 0.20-0.46); B/C, fair (K, 0.54; 95% CI, 0.40-0.67); A/D, moderate (K, 0.59; 95% CI, 0.45-0.74); B/D, moderate (K, 0.58; 95% CI, 0.46-0.70); and C/D, moderate (K, 0.50; 95% CI, 0.37-0.63). CONCLUSIONS: Interobserver agreement of DC interpretations was mostly moderate among the 3 observers, between them and histopathology, and comparable to that of other visual-based screening methods, i.e., VIA, cytology, or colposcopy.