Quality assurance in cervical screening of a high risk population: A study of 65,753 reviewed cases in Parana screening program, Brazil

Abstract

Epidemiological data from the Quality Assurance Unit (QAU) of the Cervical Cancer Screening Program of Paraná is discussed. Slides (65,753) reviewed by the QAU, from October 1997 to July 1999, were analyzed. Relations between agreement rate, diagnostic categories, and age groups were tested. The overall agreement rate was 97.04% (kappa +/- 95%, confidence interval = 0.888 +/- 0.003). Low-grade squamous intraepithelial lesion (LSIL) showed its peak prevalence in patients < or = 19 yr (8.3%). High-grade squamous intraepithelial lesion (HSIL) was more common in women between 40 and 49 yr (5.0%). Squamous-cell carcinoma (SCC) was almost exclusively seen in women > or = 40 yr. The lowest agreement rates were seen in adenocarcinoma (54.5%; kappa = 0.667) and LSIL cases (76.3%, kappa = 0.822), and in women < or = 19 yr (95.8%). It was concluded that constant monitoring to assess specific errors allows directed measures. The 10% rescreening model of quality assurance proved to be effective in a low resources setting with a positive overall financial impact.

External Quality Monitoring of the Cervical Cytopathological Exams in the Rio de Janeiro City

“…The median K index of the MEQ cycles in the city of Rio de Janeiro in this study was 0.86, coming close to the K indexes of the states of Paraná (0,88) 20 São Paulo (0.80), 19 corroborating the quality warranty of the reliability of cervix cytopathological exams performed by the laboratories evaluated. 19 20 …”

“…The false-positive results presented their highest percentages in the ASC-US category, and although they were low, 20 the “Beta laboratory” showed a tendency towards an increase in the incidence of false positives, while the “Alpha laboratory” showed a significant reduction. This reduction is important and necessary to avoid unnecessary diagnostic investigation, causing physical and emotional harm to women, undue occupation of places in specialized procedures, overloading and honoring health services.…”

“…In this regard, the results found in the present study were better than the results described in studies performed in Mato Grosso do Sul (11.4%), Goiânia (21.0%), and São Paulo (3.8%) and were surpassed only by studies performed in Paraná (1.8%). 17 18 19 20 This data may reflect the good technical quality of the team performing the cervix cytopathological exams in the Municipal Units of Primary Health Care, the continuing education and effectiveness of the External, Internal Quality Monitoring program in improving the quality of these exams.…”

“…The percentage of diagnostic disagreement in the reviewed examinations was 6.63, of which 5.38% required a change of conduct. Despite the low percentages, 20 educational interventions are necessary because of their clinical impact. They were found predominantly in the results of squamous and glandular atypia of undetermined significance, in which the interobserver variability is greater, there is greater difficulty in defining the diagnosis, increasing the chance of false-negative and false-positive results.…”