Quality in cytopathology: an analysis of the internal quality monitoring indicators of the Instituto Nacional de Câncer

Abstract

Introduction: Quality control programs are required to ensure the effectiveness of Pap smear, which still remain a key strategy for control of cervical cancer worldwide. Objective: This study was based on the retrospective and quantitative analysis of the post-analytical phase indicators from the internal quality monitoring (IQM) program for cytopathology laboratories, such as: positivity rate, atypical squamous cell (ASC)/satisfactory exams ratio, ASC/abnormal test results ratio, ASC/squamous intraepithelial lesions (SIL) ratio, percentage of tests compatible with high-grade squamous intraepithelial lesion (HSIL), and total of false negative. Materials and methods: The information was extracted from the computerized system of the Section for Integrated Technology in Cytopathology (Seção Integrada de Tecnologia em Citopatologia [SITEC]), a reference institution for cancer cytopathology, from July 2013 to June 2014. From a total of 156,888 Pap smears, 157,454 were considered satisfactory for indicator analysis and 566 were excluded because they were considered unsatisfactory and/or rejected for analysis. The data was organized in tables using Microsoft Excel 2010 software, and categorized as indicators. Results: The averages for the indicators were: 7.2% for positivity rate, 56.9 for ASC/abnormal test ratio, 4.1 for ASC/satisfactory tests ratio, 1.4 for ASC/SIL ratio, 0.6% percentage for tests compatible with HSIL, and 2.1% for false-negative rate. Conclusion: The results show that an Internal Quality Monitoring Program is essencial to ensure quality for cytopathology laboratories, and a randomized review of at least 10% of the negative exams, as recommended by the Brazilian Ministry of Health/Instituto Nacional de Câncer (INCA), since is an effective method, especially for large laboratories.

Keywords

• citopatologia
• colpocitológico
• colo uterino
• indicadores da qualidade