What the Grades Mean and Suggestions for Practice
| Grade |
Definition |
Suggestions for Practice |
| A |
The USPSTF recommends the service. There is high certainty that the net benefit is substantial. |
Offer/provide this service. |
| B |
The USPSTF recommends the service. There is high certainty that the net benefit is moderate or there is moderate certainty that the net benefit is moderate to substantial. |
Offer/provide this service. |
| C |
Note: The following statement is undergoing revision.
Clinicians may provide this 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 from this service. |
Offer/provide this service only if other considerations support the offering or providing the service in an individual patient. |
| D |
The USPSTF recommends against the service. There is moderate or high certainty that the service has no net benefit or that the harms outweigh the benefits. |
Discourage the use of this service. |
I
Statement |
The USPSTF 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. |
Read the clinical considerations section of USPSTF Recommendation Statement. If the service is offered, patients should understand the uncertainty about the balance of benefits and harms. |
Levels of Certainty Regarding Net Benefit
| Level of Certainty * |
Description |
| High |
The available evidence usually includes consistent results from well-designed, well-conducted studies in representative primary care populations. These studies assess the effects of the preventive service on health outcomes. This conclusion is therefore unlikely to be strongly affected by the results of future studies. |
| Moderate |
The available evidence is sufficient to determine the effects of the preventive service on health outcomes, but confidence in the estimate is constrained by such factors as:
- The number, size, or quality of individual studies.
- Inconsistency of findings across individual studies.
- Limited generalizability of findings to routine primary care practice.
- Lack of coherence in the chain of evidence.
As more information becomes available, the magnitude or direction of the observed effect could change, and this change may be large enough to alter the conclusion. |
| Low |
The available evidence is insufficient to assess effects on health outcomes. Evidence is insufficient because of:
- The limited number or size of studies.
- Important flaws in study design or methods.
- Inconsistency of findings across individual studies.
- Gaps in the chain of evidence.
- Findings not generalizable to routine primary care practice.
- Lack of information on important health outcomes.
More information may allow estimation of effects on health outcomes. |
* The USPSTF defines certainty as "likelihood that the USPSTF assessment of the net benefit of a preventive service is correct." The net benefit is defined as benefit minus harm of the preventive service as implemented in a general, primary care population. The USPSTF assigns a certainty level based on the nature of the overall evidence available to assess the net benefit of a preventive service.
Current as of: June 2007
