The quality and accuracy of cervical cytology: A study of five sampling devices in a colposcopy clinic

Abstract

SummaryIn a prospective random allocation trial we compared four cervical spatulas (Ayres, Aylesbury, Multi-Spatula and Cervex) by synchronous cytology and colposcopic biopsy. The spatulas were compared in three ways: (1) the presence of endocervical cells in the smear, (2) the presence of dyskaryotic cells in the smear, and (3) the efficiency of the cytology in predicting abnormal histology. We also looked at the effect of adding information from a second smear taken with an endocervical brush.Differences between spatulas in their ability to sample endocervical cells were not reflected in different frequencies of abnormal cytology, or in differences in the ability to predict abnormal histology. Addition of the information from the brush smear removed the differences in detecting endocervical cells, but did not alter the frequency of abnormal cells or the ability to predict abnormal histology. Use of the brush alone showed high rates of smears containing endocervical cells but, when compared to each of the spatulas, lower rates of abnormal cytology and a poorer ability to predict abnormal histology.Our results cast doubt on using the presence of endocervical cells to compare spatula designs. In optimum sampling conditions, alterations in spatula design appear to make little impact in improving cytology as a predictor of abnormal histology.