Table 1 Levels of Evidence for Assessing Effectiveness
Effectiveness Rating | Level of Evidence |
|---|---|
Effective | The product has passed a rigorous scientific review equivalent to a review by the FDA, Health Canada, or other governmental authority and has been found to be effective for a specific indication as an OTC drug, orphan drug, or prescription drug product. |
Likely Effective | Reputable references generally agree that the product is effective for the given indication, based o9n two or more randomized, controlled, clinical trials involving several hundred to several thousand patients, giving positive results for clinically relevant endpoints and published in established, refereed journals. |
Possibly Effective | Reputable references suggest that the product might work for the given indication based on one or more clinical trials giving positive results for clinically relevant endpoints. |
Possibly Ineffective | Reputable references suggest that the product might not work for the given indication based on one human study giving negative results for clinically relevant end-points. |
Likely Ineffective | Reputable references generally agree that the product is not effective for the given indication, based on two or more randomized, controlled, clinical trials giving negative results for clinically relevant end-points and published in established, refereed journals. |
Ineffective | Most reputable references agree that the product is not effective for the given indication, or multiple high-quality studies resulted in negative results; there are no equally reliable human studies offering convincing contradictory data. |