The effect of different sampling devices on the presence of endocervical cells in cervical smears. A systematic literature review.

A literature search examined 39 reports on the relationship between the absence of endocervical cells in a cervical smear and the sampling technique used. Using (pooled) ratios we compared the results for different pairs of sampling devices, thereby controlling for the design of each study when appropriate. The Cytobrush appears the most efficient sampling method with regard to the presence of endocervical cells. Combining the results of this review with the results of a previous meta-analysis on the effect of the sampling technique on the detection of pathology, the combined spatula and Cytobrush technique seems to be the best sampling method.