External quality control of cervical cytopathologicand the reflexinthe health public laboratory

Abstract

Introduction: external quality monitoring system was proposed as an optimal option able to improve the performance of Public Health cytology laboratoriesreducing the interobserver variation. Objective: to evaluate agreements and disagreements in cytology results submitted to diagnoses control. Methods:67,954 cases of gynaecological cytology were revised from 140 Laboratories working for the São Paulo State Public Health System during 2000 to 2004.Results: discordant diagnoses were observed in 9,641 cases (14.2%). During the years of this study it was observed a reduction of discordant results in thefollowing categories: ASCUS/AGUS, from 32.3% to 19.2%; LSIL, from 20.6% to 6.3%; HSIL, from 27.1% to 10.6% and, invasive carcinomas from 31.7% to11.5%. False positive rates (1,348) were: 64.6% ASCUS/AGUS; 28.7% LSIL, 6.5% HSIL and 0.2% of invasive carcinomas. False negative rates (1,137) were:75.1% ASCUS/AGUS; 20.2% LSIL; 3.9% HSIL and 0.8% invasive carcinomas. Conclusion: the results demonstrated progressive rates of diagnoses agreementduring the years of this study and also highlighted the crucial necessity of inter-laboratorial quality control programs.