Evaluation of agreement between conventional and liquid-based cytology in cervical cancer early detection based on analysis of 2,091 smears: experience at the Brazilian National Cancer Institute

The aim of this work was to evaluate the agreement between conventional cytology (CC) and liquid-based cytology (LBC) in cervical cancer early detection.The results of CC and LBC (DNACitoliq in 2,059 women aged 25-59 years were compared. The percent agreement, kappa coefficient, prevalence-adjusted bias-adjusted kappa coefficient (PABAK), and Chamberlain's percent positive agreement (PPA) were calculated.The percent agreement between the two methods was very good (80% and 79%, respectively, for normal versus ASCUS+; and normal versus ASCUS, AGUS and LSIL+ vs. HSIL+). The kappa coefficient indicates slight agreement (0.26 and 0.23, respectively), but when PABAK was used the agreement was good (0.61 and 0.68, respectively). PPA was high for normal results (79.2%) and low for the remaining categories.To conclude, in this study, agreement between LBC and CC was only good for normal results, which involves the majority of cases and positively influences the overall agreement rate.