What does an 'I' grade mean?

• A. Insufficient evidence to assess benefits and harms.
• B. Clear evidence of benefit or harm exists.
• C. Moderate benefit; offer with caution.
• D. No evidence issues exist.

Answer: (A)

Grade I means there is insufficient evidence to determine whether the screening or preventive service provides net benefit. In other words, the available studies are lacking, of poor quality, or show inconsistent results, so the overall balance of benefits and harms cannot be judged at this time. This signals that more research is needed, and a clear recommendation cannot be made based on current data.

In practice, when a service has an I rating, clinicians should discuss the uncertainty with patients, consider individual risk factors and preferences, and avoid routine, blanket recommendations until better evidence emerges. This is different from ratings that indicate clear benefit (strong or moderate) or a recommendation against routine use. It’s also not a description that “no evidence issues exist,” which would imply a level of certainty that the I rating does not provide.