Many U.S. primary care doctors are out of step with guidelines on Pap testing for cervical cancer -- largely because they overuse the test, according to a study published Monday.

In a survey of more than 1,200 primary care doctors nationwide, government researchers found that less than one-quarter made Pap-test recommendations that were fully consistent with major guidelines.

And the problem appeared not to be that doctors were failing to recommend testing, but that they were overusing it, according to the researchers, led by Dr. K. Robin Yabroff of the U.S. National Cancer Institute.

They report the findings in the latest issue of the Annals of Internal Medicine.

In the early part of the decade, groups including the American Cancer Society (ACS) and the American College of Obstetricians and Gynecologists (ACOG) revised their guidelines on Pap screening -- reducing the recommended frequency of testing for some women.

The changes were made in response to research showing that for many women age 30 and older, annual Pap screening is not needed -- and could have downsides like unnecessary follow-up testing and patient anxiety.

But many doctors in the current study advised testing in cases where guidelines say it is not necessary.

For example, when presented with the scenario of an 18-year-old patient with no sexual experience, half of doctors said they would recommend no Pap test -- which is consistent with guidelines.

The other half of doctors, however, said they would recommend testing at least every three years.

The findings were similar when the doctors responded to the case of a 66-year-old with lung cancer -- who, according to guidelines should stop Pap screening. More than 40 percent of the survey respondents said they would advise Pap testing, with some recommending yearly testing.

Overall, only 22 percent of doctors were guideline-consistent in all four scenarios the researchers presented. Internists did best, with 27 percent consistently adhering to guidelines; that figure was 21 percent among family and general practitioners, and only 16 percent among obstetrician/gynecologists.

Exactly why many doctors overused Pap screening is not clear, according to Yabroff's team.

Some physicians, they speculate, may disagree with the guidelines, be confused by changes in the recommendations over the years, be worried about malpractice or see a financial incentive in more-frequent testing.

The findings are based on responses from 1,212 primary care doctors who were given four patient vignettes and asked what their Pap testing recommendations would be for each case. Their answers were compared against recommendations from the ACS, ACOG and the U.S. Preventive Services Task Force.

In general, the groups recommend that women begin Pap testing at age

21 or within three years of first having intercourse, whichever comes first. 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 the ages of 65 to 70, if their recent tests have yielded normal results. According to the ACS, women can also stop Pap screening if they've had a total hysterectomy for a non- cancerous condition or have a serious disease that is limiting their life expectancy.

These latest findings suggest that many doctors need a better understanding of those guidelines, according to the researchers.

They did find, though, that some doctors -- including those younger than 40, those who were board-certified and those who were part of large, multi-specialty practices -- were more likely than others to follow Pap screening guidelines.

SOURCE: Annals of Internal Medicine, November 3, 2009.

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