Concordance in the Interpretation of Cervical Cytology for the Early Diagnosis of Cervical Cancer

摘要

Objective: To identify the diagnostic concordance in the interpretation of cervical smears. Material and Methods: Cross-sectional study from October 2011 to January 2013. 50 samples were read by every 4 cyto-technologists who are the total staffs that read and interpret cytological specimens from a public health institution of the city of San Luis Potosí, México. The cytological diagnosis was confirmed by a certified pathologist. Checklist was developed to determine the quality of the interpretation composed of three sections: adequate sample, inadequate sample and cytological diagnosis. The diagnostic report was made by Bethesda System 2001 classification. Diagnostic concordance was measured through the Kappa coefficient. To establish the differences in cytological diagnosis between each cyto-technologist, chi square test was applied. Results: The concordance is acceptable in the classification of samples as inadequate (k = 0.66). The negative diagnosis was a significant concordance between each cytotechnologist and pathologist; however, no case had very good concordance. In the epithelial abnormalities, only the cytotechnologist 2 had significant concordance with the pathologist, however, its concordance is low. In the case of glandular abnormalities, only cytotechnologist 1 had no significant concordance with the pathologist. The percentage of true negatives was 30%, true positives 20%, false negatives 50% and false positives 0 %. There are significant differences between the readings of cyto-technologist 1 and 2 (p < 0.008), between 1 to 4 (p < 0.001), between 2 and 3 (p < 0.05), and finally between 3 and 4 (p < 0.003). Conclusions: The concordance between cyto-technologists and pathologists is below the required minimum level set by national and international standards.