Results of a control quality strategy in cervical cytology

Abstract

Objective: To determine the efficacy of a quality control strategyin cervical cytology in the detection of high-grade squamousintraepithelial lesions. Methods: Forty-two patients were selectedwho underwent a Pap smear and cervical uterine biopsy betweenApril 2008 and December 2009, with evidence of a high-gradesquamous intraepithelial lesion in one or both tests. The statisticalparameters of the smear test were calculated before and aftersystematic meetings for review of the archived test results (6years), in which the following was done: interobserver diagnosticconsensus; cytohistological correlation, with the latter as goldstandard; and evaluation of the therapeutic status of each patient.Results: Once these controls were applied, it was noted thatsensitivity and positive likelihood ratio of the test for high-gradesquamous intraepithelial lesion increased 9.5% (34.5 to 44%) and0.45% (1.64 to 2.09%), respectively, while specificity remained at79%. Reduction in interference of false-negative results associatedwith errors in the analytical phase of the cytological productiveprocess gave an estimate of failures in collection of the specimens(pre-analytical phase). Conclusion: In addition to improving theperformance of the cytological diagnosis of the high-grade squamousintraepithelial lesion, the proposed quality control strategy allows areflection on the causes of incorrect or conflicting scrutiny.

Keywords

• Efficacy
• Quality control
• Intraepithelial cervical neoplasia
• Cervix uteri/pathology