What does a 'D' grade mean?

• A. Harms outweigh benefits; the service should not be offered.
• B. The net benefit is moderate; the service should be offered.
• C. Insufficient evidence to assess benefits and harms.
• D. The service should be offered; harms unknown.

Answer: (A)

In USPSTF grading, a grade that recommends against a service is given when the balance of harms to benefits is unfavorable—there is high certainty that harms outweigh benefits or there is no net benefit. So the service should not be offered to patients in general. This is population-level guidance, not a statement about every individual case. It differs from insufficient evidence to assess benefits and harms (where net benefit can’t be determined) and from grades that support offering the service (substantial or moderate net benefit) or offering it selectively (small net benefit).