Papanicolaou smear adequacy: the cervical cytobrush and Ayre spatula compared with the extended-tip spatula.

Papanicolaou smears have false-negative rates of 6 percent to 56 percent that are due, in large part, to inadequate sampling of endocervical cells. A randomized, prospective trial was conducted comparing the adequacy of Papanicolaou smears obtained with the cytobrush and Ayre spatula with smears obtained with the extended-tip spatula, as measured by the presence of endocervical cells. One hundred of 111 Papanicolaou smears obtained with a cytobrush and Ayre spatula contained endocervical cells (90.1 percent), compared with 68 of 105 smears obtained with the extended-tip spatula (64.8 percent) (chi 2 = 18.6, P less than 0.0001). There were no other significant differences between the two study groups for age, gravidity, parity, and hormone usage. The combination of the cytobrush and Ayre spatula appears to be superior to other methods that are currently used to obtain Papanicolaou smears.