The Comparison of The Bethesda System (TBS) and Richart Score (RS) in the evaluation of cervical cancer lesions among women attending Machakos Level Five County hospital in Kenya

The laboratory performance of The Bethesda System against the Richart Score for quality assurance

Abstract

Cervical cancer diagnosis is achieved through simultaneous conductance of both cellular as well as tissue biopsy screening. TBS grades cellular lesions while the gold standard (RS) is a confirmatory quality assurance test for ascertaining cervical tissue lesion localization.  To compare the laboratory performance of TBS against RS. Cervical specimens for cancer lesion examination from 176 women of >22<58, in this cross-sectional study were obtained. Laboratory performance of TBS against RS was done by assessing variable associations (Multivariate regression), evaluating test accuracy (McNemar test), test analogy (Kappa test) and degree of test sensitivity, specificity and predictive value (plotting the receiver operating characteristic-ROC curve), at 95% CI. TBS results were classified as Normal epithelial cells 51%, ASCUS 28%, LGSIL 15% and HGSIL 6%. RS recorded Normal cervix 76%, CIN1 16%, CIN2 7% and CIN3 1%. The sensitivity of TBS against the gold standard was 88%, specificity 61%, positive predictive values 49%, negative predictive values 93%, Kappa, 0.810, McNemar, 0.035 at 95% CI and Fishers exact <0.001. TBS achieved a high level of accuracy, analogy and reliability in terms of sensitivity, specificity and predictive value against the gold standard. TBS is an effective test for assessing cervical cancer lesions. Regular quality assurance conductance of TBS is therefore recommended.