The American Cancer Society and American College of Obstetricians and Gynecologists recommend that women begin pap testing at age 21 or within three years of becoming sexually active. They also advise yearly screening until age 30, at which point the frequency can be cut to every two to three years if a woman has had normal results on three consecutive pap tests.
Women can stop screening after age 65 if their recent tests have been normal.
The findings are reported in the latest issue of the Annals of Internal Medicine.