Practice Alert

Preventive services: The good, the bad, and the unproven

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Latest recommendations from the USPSTF reinforce some long-standing advisories and contradict others.


 

References

The past 12 months have been busy ones for the United States Preventive Services Task Force (USPSTF), which issued 34 new recommendations since our last Practice Alert on the group’s activity a year ago. Some recommendations address controversial topics, such as cholesterol screening, and several others—on topics such as prostate cancer screening and acceptable tests for detecting colorectal cancer—differ from those of such prominent groups as the American Cancer Society (ACS).

TABLE 1 provides a breakdown of the 5 categories of USPSTF recommendations (A, B, C, D, I). We’ll start with recent D recommendations (TABLE 2), services the Task Force recommends against, to emphasize that some preventive measures—even if they are widely touted—either provide no benefit or cause more harms than benefits.

TABLE 1
USPSTF recommendation categories

A Recommendation: The Task Force recommends the service. There is high certainty that the net benefit is substantial.
B Recommendation: The Task Force recommends this service. There is high certainty that the net benefit is moderate or there is moderate certainty that the net benefit is moderate to substantial.
C Recommendation: The Task Force recommends against routinely providing the service. There may be considerations that support providing the service in an individual patient. There is at least moderate certainty that the net benefit is small.
D Recommendation: The Task Force recommends against the service. There is moderate or high certainty that the service has no net benefit or that the harms outweigh the benefits.
I Statement: The Task Force concludes that the current evidence is insufficient to assess the balance of benefits and harms of the service. Evidence is lacking, of poor quality, or conflicting, and the balance of benefits and harms cannot be determined.

TABLE 2
The USPSTF recommends AGAINST

  • Using aspirin to prevent stroke in women <55 years of age and to prevent myocardial infarction in men <45 years.
  • Screening for asymptomatic bacteriuria in men and nonpregnant women.
  • Screening adults for chronic obstructive pulmonary disease using spirometry.
  • Screening for colorectal cancer in adults >85 years of age.
  • Routine screening for colorectal cancer in adults ages 76 to 85 years. There may be individual considerations that support screening in individual patients.
  • Screening for prostate cancer in men ≥75 years of age.

What not to do

The most notable new D recommendations advise against screening men ≥75 years of age for prostate cancer and against screening for colorectal cancer after age 85. The Task Force also recommends against routine screening for colorectal cancer after age 75, although individual patient considerations may influence your decision about this screen for patients between ages 76 and 85. Bear in mind that the benefits of early detection of colon cancer decline after age 75 because of the time lag between early intervention and benefit and because of competing causes of morbidity and mortality.1

Cancer screening controversies. The recommendations for an age cutoff for prostate and colon cancer screening differ from those of the ACS, which lists no age cutoff for screening for either condition.2 In fact, the Task Force does not recommend screening for prostate cancer at all. Its rationale is that before age 75, the evidence is insufficient to evaluate benefits and harms, and after 75 there is good evidence that screening does more harm than good. The ACS no longer recommends routine prostate cancer screening, but does say that when a patient leaves the decision to the physician, screening should be performed.

Thumbs down on these, too. The Task Force now recommends against using spirometry to screen for chronic obstructive pulmonary disease and against using aspirin for preventing stroke in women <55 years and myocardial infarction (MI) in men <45 years. (See below for a fuller discussion of aspirin as a preventive measure.) The Task Force also recommends against screening for asymptomatic bacteriuria in men and nonpregnant women.

Recommended interventions

Now for the preventive interventions the USPSTF advises you to perform. They include:

Prescribing low-dose aspirin. The most complicated positive recommendations are those for low-dose aspirin to prevent MI in men and stroke in women. Aspirin is effective in preventing these conditions, but carries the risk of major gastrointestinal (GI) bleeding and cerebral hemorrhage. For younger patients, as we’ve seen in the previous section, the Task Force finds the risks of prophylactic low-dose aspirin therapy outweigh the benefits. But for older patients (men between the ages of 45 and 79 years and women ages 55-79), aspirin is recommended when the potential benefit of reducing the incidence of MI in men and stroke in women outweigh the harms. To assist clinicians in weighing the potential benefits and harms, the USPSTF provides a link to a coronary heart disease risk calculator, as well as several tables comparing numbers of prevented heart attacks for men and strokes for women by age and risk category, as well as risks of bleeding complications.3

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