Women who get annual pap smears may receive no benefit over women who are tested less frequently and it may in fact be causing harm since frequently tested women may also be at increased risk of unnecessary treatment and anxiety, researchers from the Centers for Disease Control and Prevention (CDC) are warning.

Researchers analyzed 1991-1998 data from a national study of nearly 130,000 women who had a first Pap test reported as normal, and at least one subsequent Pap test performed within the following 9 to 36 months.

"Many times, especially for low-grade abnormalities, there's a lot of false positives (results which appear positive, but are in fact negative), and women may be biopsied and receive other treatment because of the Pap test result," Dr. Mona Saraiya from the CDC told Reuters Health. "These symptoms might have gone away if we'd left (the women) alone," she added. ""There needs to be more research to show what actual harmful morbidity is associated with an abnormal Pap."

"Women who were screened annually rather than less frequently might have worse health outcomes if low-grade results of undetermined clinical importance lead to further testing and unnecessary patient morbidity and anxiety," the researchers conclude.

Current guidelines from the American College of Obstetricians and Gynecologists suggest that most women should have annual Pap tests. The American Cancer Society guidelines suggest that screening less frequently than every year might be adequate for women who have had three negative annual tests.

Morbidity and Mortality Weekly Report 2000;49:1001-1003