Relation between sampling device and detection of abnormality in cervical smears: a meta-analysis of randomised and quasi-randomised studies.

OBJECTIVE

To assess the diagnostic yield of different sampling devices used in cervical screening.

DESIGN

Meta-analysis of randomised and quasi-randomised studies.

SETTING

All randomised and quasi-randomised studies comparing the yield of cytological or histological abnormalities when two or more different sampling devices were used.

SUBJECTS

85,000 patients included in 29 studies reported in 28 papers.

MAIN OUTCOME MEASURES

Pooled relative risk and 95% confidence interval of the yield of mild dysplasia or worse in smears recovered by each sampling method versus each other method with which it was compared; sensitivity or positive predictive value, or both, of cytological versus histological results in six studies from which sufficient data were available.

RESULTS

There were no substantial differences in the yield of cytological abnormalities between the Ayre spatula, the Cytobrush, and the cotton swab used alone. There were also no substantial differences in the yield of cytological abnormalities between the extended tip spatula, the Ayre spatula combined with the Cytobrush or cotton swab, or the Cervex brush. The Ayre spatula, Cytobruah, or cotton swab used alone generally performed significantly worse than the combinations, the extended tip spatula, or the Cervex brush. There were no substantial differences in sensitivity or positive predictive value between the sampling methods.

CONCLUSIONS

These results support the use of either the extended tip spatula, a combination of any spatula plus the Cytobrush or cotton swab, or the Cervex brush for cervical screening.