Prediction of high-grade squamous intraepithelial lesions using the modified Reid index

Colposcopic grading provides an objective and meaningful guide to histologic severity and neoplastic progression of squamous intraepithelial lesions of the cervix. The objective of this study was to develop a more efficient and convenient method to overcome procedural complexities involved with the traditional Reid index in prediction of high-grade squamous intraepithelial lesion (HSIL).

The Reid index uses four colposcopic signs (margin, color, vessel, and iodine staining). The proposed modified Reid index system specifically incorporates the location of the lesion within the transformation zone in place of iodine staining. Three hundred women with suspected or abnormal cytologies or abnormal cervicographic findings were evaluated by colposcopy, directed biopsy, and HPV testing by the Hybrid Capture II method, which detects high-risk HPV DNA types.

The sensitivity of high-risk HPV testing for detecting HSIL was 94.4%, the specificity was 65.0%, the positive predictive value was 75.5%, and the negative predictive value was 91.0%. The results of the colposcopic impression using the modified Reid index were superior to HPV testing. The sensitivity, specificity, positive predictive value, and negative predictive value of the colposcopic impression for detecting HSIL were 91.3, 92.9, 93.6, and 90.3% respectively.

These results strongly indicate that the modified Reid index can accurately predict the histologic grade of squamous intraepithelial lesions of the cervix and can be applied easily and objectively in clinical practice without affecting the diagnostic accuracy of the traditional Reid index.