Comparative cytologic yield and quality of three Pap smear instruments.

BACKGROUND

Various sampling techniques of the cervix have established false negative rates ranging from 18% to 45%. A number of studies suggest that this false negative rate can be reduced by sampling techniques that are associated with higher yields of endocervical cells.

METHOD

This study enrolled 301 women, each of whom had a Pap smear obtained using three different sampling instruments (a cervical brush, a plastic spatula, and a cotton swab) in random order.

RESULTS

The cervical brush yielded a better endocervical sample than either of the other instruments (P < .001), and there was no difference between the swab and spatula. In addition, the recovery of endocervical cells increased with each additional sample taken, regardless of instrument used (P < .001), although the difference in yield between the second and third samples was not significant.

CONCLUSIONS

To enhance the yield of endocervical cells in Pap smear sampling, consideration should be given to using the cervical brush routinely as a sampling instrument and to taking more than one sample per screening.