A study comparing the Cell-Sweep and the Cytobrush and Ayre spatula found that though the proportion of smears lacking endocervical cells was statistically greater with the Cell-Sweep than with the Cytobrush/Ayre spatula, there was no difference in the rate of detection of atypical squamous cells and low grade SIL. The Cell-Sweep appeared to detect an increased number of high grade SILs.