What does a 'D' grade indicate?

• A. Insufficient evidence to assess net benefit.
• B. No net benefit or harms outweigh; not routinely recommended.
• C. The service has a small net benefit and should be offered after individual consideration.
• D. The service has a large net benefit and should be routinely offered.

Answer: (B)

A D grade means the preventive service should not be routinely offered because there is high certainty that it has no net benefit or that harms outweigh benefits. This places it in contrast to A and B, which are recommended because there is substantial or moderate net benefit, and to C, which may offer a small net benefit and be considered after individual discussion. The key idea is that, for a D rating, the balance of benefits to harms does not justify routine use, though in rare, highly individual circumstances a clinician might discuss it—but the default recommendation is not to offer it routinely.