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

Internal quality control indicators in cervical cytopathology of a university laboratory

“…The RR of negative and unsatisfactory smears can reduce false‐negative rates . In the study of Araújo et al the average positivity rate between July 2013 and June 2014 at National Cancer Institute was 7.2%, compared with 6.1% in the 2007 study of Manrique et al Costa et al showed a PI of 2.60% by performing an historical analysis of the cervical cancer screening programme in Brazil from 2006 to 2013. In the study of Djemli et al, of 114 false‐positive cases, they found 1.3% on RPS (73% were determined to be reactive changes, whereas the remainder did not show any significant findings upon full screening).…”

“…Low positivity indicates that positive samples are not being identified by the laboratory, leading to false‐negative results. So, when the positivity rate is very low, it is necessary to evaluate and strengthen the IQM and the quality of the data collection . In Brazil, the majority of cytopathology laboratories have positivity rates below the recommended level, indicating that they do not perform IQM properly .…”

“…17 Other rates are 0.5% in the USA, 0.6% in Canada, 1.1% in the UK and 1.14% in Norway. In Brazil, the rate of HSIL has been reported as 0.35% and 0.6% …”

“…When the percentage of detected HSIL among satisfactory examinations is below the recommended level, this can be a sign of high rates of false‐negative results, which consequently delays appropriate clinical management and treatment of women with intraepithelial lesions . It is important to note that the detection of HSIL is the focus of screening programmes for cervical cancer, in an attempt to decrease its incidence and mortality .…”

“…Internal quality monitoring (IQM) in cervical cytopathology allows laboratories to identify any nonconformity, with the aim of improving the detection of epithelial abnormalities and, consequently, reduce false‐negative results . IQM should comprise a regular set of systematized actions, including specimen adequacy monitoring, scrutiny time observation, observers’ workload control, hierarchical review and review of negative smears . The IQM control methods considerably increase the sensitivity, and consequently, the detection of precursor lesions of cervical cancer …”