Surrogate indicators of sensitivity in gynecologic cytology: Can they be used to improve the measurement of sensitivity in the laboratory?

Abstract

Background:Measuring the sensitivity of screening in gynecologic cytology in real life is problematic. However, other quality measures may correlate with sensitivity, including the atypical squamous cells (ASC)/squamous intraepithelial lesion (SIL) ratio. Whether these other measures can function as “surrogate indicators” for sensitivity and improve the assessment of sensitivity in the laboratory is not known.Materials and Methods:We compared multiple quality measures with true screening sensitivity in a variety of situations.Results:The abnormal rate, ASC rate, and ASC/SIL ratio were all highly correlated (r =.83 or greater) with sensitivity when the overall laboratory sensitivity was low (85%) but became less correlated (.64 or less) or uncorrelated when the screening sensitivity was higher (88% or 95%, respectively). Sensitivity was more highly correlated with the abnormal rate than the ASC/SIL ratio at low screening sensitivity. While thresholds could be set that were highly sensitive and specific for suboptimal screening, these thresholds were often less than one standard deviation away from the mean.Conclusion:The correlation of the abnormal rate and the ASC/SIL ratio with sensitivity depends on overall sensitivity. Standards to define minimum screening sensitivity can be defined, but these standards are relatively narrow. These features may limit the utility of these quality measures as surrogates for sensitivity.

What does the data of 354,725 patients from turkey tell US about cervical smear epithelial cell abnormalities? - the epithelial cell abnormality rate is increasing - quality control studies and corrective activity are musts

“…The AsC/sIl is reported to be less variable when compared to eCA and creates mathematical data recommended for use in QA (16,19,21). This ratio is recommended to be 1.73 -2.05 for cytopathologists and 0.87-4.5 for cytotechnologists in several articles (16,21) and under 2-3 in others (16,19,20).…”

“…This ratio is recommended to be 1.73 -2.05 for cytopathologists and 0.87-4.5 for cytotechnologists in several articles (16,21) and under 2-3 in others (16,19,20). The AsC/sIl ratio in hospital-based studies from Turkey varies between 2.25 and 12.6 (3-13).…”

“…AsC is expressed as the total of AsCus and AsC -cannot exclude High grade squamous Intraepithelial lesion (HsIl) (AsC-H) (16)(17)(18). The recommended AsCus/sIl ratio is 2 to 3 in different publications (16,19,20) and between 0.87 and 4.49 in others (16,20,21). The reported hospital based ratios from Turkey vary between 3.28 and 12.6 (3-13) and 2.83 in the multi-center study of the Turkish Cervical Cancer and Cervical Cytology research Group (14).…”

Patients with epithelial cell abnormality in pap smears: correlation of results with follow-up smears andcervical biopsies

“…The ASC/SIL ratio is reported to be less variable when compared to the other parameters and creates mathematical data recommended for use for quality control (8,10,12). This ratio is reported as 1.73 -2.05 for cytopathologists and 0.87-4.5 for cytotechnicians in the literature (10)(11)(12).…”

“…The ratio of the atypical squamous cells (ASC), which is expressed as the total of ASCUS (Atypical Squamous Cells of Undetermined Significance) and ASC-H (Atypical Squamous Cells -cannot exclude HSIL) diagnoses to the squamous intraepithelial lesion (SIL) diagnosis is an important, easily calculated quality control data for pathology laboratories (4,8,9). The recommended ASC/SIL ratio is 2 to 3 in various articles (8,10,11), and between 0.87 and 4.49 in others (10)(11)(12). Ratios reported from Turkey vary between 3.28 and 12.6 in single-center studies (7,(13)(14)(15)(16)(17)(18)(19).…”