The United States Preventive Services Task Force (USPSTF) is "an independent panel of experts in primary care and prevention that systematically reviews the evidence of effectiveness and develops recommendations for clinical preventive services." The task force, a panel of primary care physicians and epidemiologists, is funded, staffed, and appointed by the U.S. Department of Health and Human Services' Agency for Healthcare Research and Quality. 
The methods of evidence synthesis used by the Task Force have been described in detail. In 2007, their methods were revised.The USPSTF explicitly does not consider cost as a factor in its recommendations.
The Task Force assigns the letter grades A, B, C, D, or I to each of its recommendations, and includes "suggestions for practice" for each grade. The Task Force also defined levels of certainty regarding net benefit.
- Grade A. Recommended. There is high certainty that the net benefit is substantial.
- Grade B. Recommended. There is high certainty that the net benefit is moderate or there is moderate certainty that the net benefit is moderate to substantial.
- Grade C. No recommendation. Clinicians may provide the service to selected patients depending on individual circumstances. However, for most individuals without signs or symptoms there is likely to be only a small benefit.
- Grade D. The Task Force recommends against this service. There is moderate or high certainty that the service has no net benefit or that the harms outweigh the benefits.
- I statement. The current evidence is insufficient to assess the balance of benefits and harms.
Levels of certainty vary from high to low according to the evidence.
- High. Consistent results from well-designed studies in representative populations that assess the effect of the service on health outcomes.
- Moderate. The evidence is sufficient to determine the effects of the service, but confidence is limited. The conclusion might change as more information becomes available.
- Low. The evidence is insufficient to assess effects on health outcome.
In 2009, the USPSTF updated its advice for screening mammograms. Screening mammograms, or routine mammograms, are X-rays given to apparently healthy women with no symptoms or evidence of breast cancer in the hope of detecting the disease in an early, easily treatable stage. The advice about using mammography in the presence of symptoms (such as a palpable lump in the breast) is unchanged.
The previous advice was for all women over the age of 40 to receive a mammogram every one to two years. The new advice is more detailed.
For women between the ages of 50 and 74, they have recommended routine mammograms once every two years in the absence of symptoms. Most American women who are diagnosed with breast cancer are diagnosed after age 60.
No recommendation is made about mammograms in women over the age of 75, as very little research has been performed in this age group.
The Task Force recommended against routine mammography to screen asymptomatic women aged 40 to 49 years for breast cancer. Patients in this age group should be educated about the risks and benefits of screening, and the decision whether to screen or not should be based on the individual situation and preferences. The old advice was based on "weak" evidence for this age group. The new advice is based on improved scientific evidence about the benefits and harms associated with mammography and is consistent with recommendations by the World Health Organization and other major medical bodies. Their recommendation against routine, suspicion-less mammograms for younger women does not change the advice for screening women at above-average risk for developing breast cancer or for testing women who have a suspicious lump or any other symptoms that might be related to breast cancer.
The change in the recommendation for younger women has been criticized by some physicians and cancer advocacy groups, such as Otis Brawley, the chief medical officer for the American Cancer Society, and praised by physicians and medical organizations that support individualized and evidence-based medicine, such as Donna Sweet, the former chair of the American College of Physicians, who currently serves on its Clinical Efficacy Assessment Subcommittee.
The USPSTF recommendation, which focuses solely on clinical effectiveness without regard to cost, formally reduces the grade given for evidence quality from "B" to "C" (limited evidence prevents a one-size-fits-all recommendation) for routine mammograms in women under the age of 50. With a grade C recommendation, physicians are required to consider additional factors, such as the individual woman's personal risk of breast cancer. Pending health care legislation would require insurance companies to cover any and all preventive services that receive an "A" or "B" grade, but permit them to use discretion on preventive services that receive a worse grade.
The Vitter amendment to pending legislation in the U.S. Senate instructs insurers to disregard the task force's recommendation against frequent routine mammograms in asymptomatic younger women, and requires them to provide free annual mammograms, even for low-risk women, based on the outdated 2002 report. This proposal is not yet law and may change. The efforts by politicians to reject the committee's scientific findings have been condemned as an example of unwarranted political interference in scientific research.
Prostate cancer screening
From 1984 to 1989, the task force's stated purpose was to "develop recommendations for primary care clinicians on the appropriate content of periodic health examinations."
- USPSTF on AHRQ website
- USPSTF website